WO2011011644A2 - Method to improve laser treatment of disease - Google Patents

Abstract

The invention provides methods of administering a non-destructive laser treatment to a subject with a disease condition of a barrier tissue such as the skin or mucosa, wherein the laser exposure raises the temperature in the treated tissue by at least 2°C, leading to improvement in the disease condition treated without causing significant cellular necrosis or tissue disruption in and around the laser-exposed tissue as a result of laser exposure. The laser combines ultrashort pulse durations with high pulse frequency to deliver irradiances of about 0.1-10 W/cm² over treatment periods of seconds to minutes. The laser can be administered externally or internally through an endoscope or catheter. This method can be useful for treating viral, bacterial, fungal or parasitic infections such as human papillomavirus infection, onychomycosis, and leishmaniasis as well as genetic abnormalities such as actinic keratosis, lichen planus, squamous cell carcinoma, basal cell carcinoma and melanoma.

Description

METHOD TO IMPROVE LASER TREATMENT OF DISEASE

RELATED APPLICATIONS

This application claims priority from a U.S. Provisional Patent Application No. 61/227,527, filed on July 22, 2009, which is incorporated herein in its entirety.

BACKGROUND OF THE INVENTION

Therapeutic lasers used in medicine generally fall into two categories: nondestructive, low-energy lasers ("cold lasers") designed to generate largely athermal biological effects in tissue, and destructive lasers designed to selectively damage or destroy tissue.

The first type of laser therapy, sometimes referred to as low-level laser therapy (LLLT) or cold laser therapy, tend to use very low power density or irradiation with a wide variety of wavelengths, pulse durations and frequencies. These lasers are used, for example, for stimulating cellular processes such as mitochondrial respiration resulting in the production of pro-angiogenic or other growth factors that are important in cellular regeneration and repair. By its nature, LLLT is designed to work through photochemical mechanisms and cause almost imperceptible changes in the temperature of the cells subject to such lasers. In essence, LLLT is an athermal medical treatment. In the paradigm of LLLT, the dose response to laser treatment is held to be biphasic, with a maximum effect followed by a suppressive effect. Typical maximum effective irradiances are reported in the range of about 1-45 mW/cm² (Huang et al. 2009). Above this range the biological effects dose-response is often reported to be negative.

In contrast to cold lasers, most FDA-approved medical lasers are designed to selectively damage or destroy tissue. By varying the parameters of laser treatment (wavelength, power, pulse duration, pulse frequency, pulse energy, exposure diameter, and exposure duration), a range of destructive effects can be generated in tissues including protein denaturation, coagulation, welding, cutting, carbonization, vaporization, ablation, fragmentation and disruption. Compared to the irradiance required for LLLT applications, minimal irradiances for tissue destruction effects in the visible to mid- infrared spectrum are generally about 10 W/cm . Laser methods of tissue destruction or disruption rely on progressively higher irradiances. For the most part, increases in power density require shorter treatment durations. At very high irradiances, treatment durations can be as little as fractions of a second. The majority of these destructive laser treatment techniques involve generation of photothermal effects in the tissue, although at specific parameters, photoacoustic, photokinetic and photochemical effects are more prominent. The typical outcome of such laser treatments are selective killing of laser-exposed cells (e.g., protein denaturation, coagulation, welding, carbonization) or disruption of the tissue (e.g., cutting, vaporization, ablation, fragmentation, disruption).

Therapeutic Laser Hyperthermia

Between the zones of athermal biological stimulation and tissue destruction is an area (laser irradiances of about 0.1 W/cm² to 10 W/cm²) where lasers can generate cellular stress (primarily thermal stress) on cells and tissues without causing uncontrolled cell death (necrosis) or disruption of the treated tissue (Figure 1). Very few applications of lasers or approved medical laser devices exist with these parameters because there are currently few indications of medical efficacy at these irradiances,

One useful medical application for lasers operating in the zone of non-destructive thermal stress is the therapeutic hyperthermia of diseased tissues. These approaches to hyperthermia specifically seek to control the thermal energy generated in the tissue to keep it below the level that causes protein damage, cellular necrosis and significant tissue disruption. Avoiding necrosis of the tissue is desirable because cellular necrosis is often accompanied by inflammation, which can represent a complication to treatment, and because causing necrosis of treated tissues can also lead to fibrosis or scarring. Below the thermal dose threshold causing cellular necrosis lays a more desirable therapeutic range that can induce apoptosis instead.

Necrosis and apoptosis both result in the death of a cell, but occur in quite different ways. Necrosis is the chaotic, uncontrolled, and non-programmed death of a cell or, collectively, of a tissue, that typically occurs from irreversible intracellular damage resulting in the severe disruption of the cellular membrane and release of the cellular contents. Necrosis is characterized by impairment of the cell's ability to maintain homeostasis leading to an influx of water and extracellular ions into the cell,

vacuolization of the cytoplasm, breakdown of the cellular DNA, and organelle membrane and cellular membrane rupture. The ultimate breakdown of the cell membrane releases the contents of the cell, including lysosomal enzymes, into the extracellular space. As a result, necrosis often results in inflammatory response.

In contrast, apoptosis is the orderly process of programmed cell death. It is a genetically-regulated process that involves a series of intracellular signaling cascades. Apoptosis is a normal part of the cell life cycle. Apoptotic cells are characterized by membrane blebbing, cell shrinkage, condensation of chromatin, and fragmentation of DNA followed by rapid engulfment of the corpse by neighboring cells or other phagocytic cells. Unlike necrosis, apoptosis does not result in the significant release of the contents of the cell into the extracellular space and therefore does not trigger inflammatory responses.

The threshold for significant necrosis in most cells exposed to a sustained level of heat occurs at about 45° C, which is destructive for may protein structures, while the onset for apoptosis generally occurs around 42° C (Harmon et al. 1990). Between approximately 42-45° C, apoptosis based on hyperthermia is highly temperature sensitive. Small changes in temperature above 42° C exponentially increase the number of cells undergoing apoptosis (Roti Roti 2008). Heat causes increased apoptosis in cells through a variety of means including proliferating abnormally-folded proteins, inducing nuclear damage and destabilizing the cell membrane. Many of these cellular changes trigger intracellular signaling cascades that result in cellular apoptosis. There are a number of well-characterized and independent signaling pathways for apoptosis (Strasser et al. 2000).

Therapeutic hyperthermia is based on the principle that hyperthermic doses affect diseased cells and tissues to a greater extent than normal tissue, resulting in higher rates of apopotosis in abnormal tissues compared to healthy tissues. Based on this principle, clinicians seek to control the hyperthermic dose in a way that maximizes the apoptotic killing of diseased tissue and avoid thermal necrosis. Traditionally, control over hyperthermic apoptosis involves focusing the heat on the diseased tissue volume, as well as careful control over the hyperthermia dose delivered.

Since the effect of hyperthermia is a property of the heat exposure duration and not solely of the temperature, responses to hyperthermia are dose dependent. Delivery of sufficient doses of heat required to cause significant apoptosis in diseased tissues that spare normal tissues typically require reaching temperatures of between 41-45 ⁰C that are maintained over a 30-60 minute period. Hyperthermia can be induced using a variety of modalities including conduction heating, radiofrequency, microwaves and ultrasound. In 1987, Daikuzono and his colleagues (1987) demonstrated an approach to hyperthermia using an Nd: YAG laser as the heating source. Over the last several decades, a number of applications of laser hyperthermia have been explored, most focused on direct or adjuvant treatments of cancer.

Short-Duration Laser Hyperthermia for Diseases of Barrier Tissues

In general, therapeutic hyperthermia for cancer requires sophisticated instruments and careful dosimetry and treatment planning to ensure that an adequate thermal dose is delivered to the total tumor mass. The utility of lasers as means of delivering

hyperthermia is limited because their depth of penetration is restricted by absorption of laser energy to a much greater degree than other types of energy devices. More recently it has been appreciated that laser hyperthermia can be effectively applied to specific diseases of barrier tissues such as the skin where the overall mass and the size of the diseased area is limited, and where the effectiveness of energy absorption is an asset rather than a liability. For the treatment of relatively thin barrier tissues such as the skin, oral and gut mucosa, or the stomach or bladder lining, the efficiency of absorption of laser light by tissue allows large quantities of energy to be efficiently delivered with relatively small devices. In addition, less sophisticated approaches are required to raise the temperature in the target tissue to therapeutic levels. This can be accomplished in a relatively short period of time compared with traditional applications of laser

hyperthermia. Several published studies discuss the results of using short-term laser hyperthermia to treat a variety of diseases in the skin. These studies all utilized a continuous wave Nd: YAG laser operating at 1064 nm, and involved treatment regimens between about 30 seconds and 2 minutes per treatment.

The initial study was published by a group at University of Regensburg in 1994

(Pf au et al. 1994). This pilot study involved treatment of a resistant skin wart with a 20 second laser dose at 10 Watts with a beam diameter of 8 mm. The treatment was given twice over a six week interval. The subject experienced complete remission after the second treatment. This group conducted a larger follow-up study (Pfau et al. 1995) in which 31 patients with recalcitrant warts were treated with an Nd: YAG laser. The laser output was 10 W, spot size 8 mm, and irradiation time sufficient to achieve a surface temperature of about 4O⁰C for 30 s (45⁰C subsurface). Three treatments were provided with an interval of three weeks between each treatment. Excellent treatment response was achieved in 77% of the patients with no recurrence in that group during a follow-up period of up to 9 months. By modifying the technique of Pfau's group, an Egyptian team (El-Tonsy et al. 1997) was able to increase the efficacy of the treatment to 95%.

El-Tonsy's group subsequently applied the laser hyperthermic technique to the treatment of basal cell carcinoma of the head and neck (2004). They treated 37 patients using up to a one-minute exposures of continuous-wave Nd: YAG laser light at 10 Watts to an 8 mm skin target (20 W/cm irradiance, total dose per exposure 300 J/cm ).

Subjects were treated every six weeks until histopathologic confirmation of cure. Lesions less than 1 cm in diameter received two treatments; those 1-2 cm in diameter received three treatments, those larger than 2 cm in diameter received four sessions. Target temperature of the treated area was measured during therapy, with the goal of maintaining target temperature at 45° C. All but one subject showed long-term cure of the cancer lasting up to five years after treatment. One subject was initially responsive but had a later recurrence of the cancer.

A similar study was conducted by a Polish group (Rubisz-Brzeziήska and

Bendkowski 1990). This group treated 94 lesions in 51 subjects with BSC, AK, and cornu cutaneum using a continuous Nd:YAG laser. Single treatments were given to lesions ranging from 7 to 24 mm in size using doses ranging from 50 to 240 J/cm².

Similar clearance rates of disease were noted.

These approaches to the use of lasers utilized continuous wave lasers to raise the temperature in the tissue to a significant degree. In each study the temperature in the treated tissue was raised to about 45° C for about one to two minutes (temperature at the skin surface was typically cooler, in the range of 40-42° C). While these studies show the ability of a laser to produce therapeutically useful hyperthermia, these studies were not without complication. To get tissue response, irradiance near the threshold of thermal damage (in most studies about 20 W/cm²) are used. In all cases study subjects experienced stinging or burning pain during the laser treatment. When this approach is used on more sensitive skin tissues, such as in the El Tonsy study, the high power of the laser treatment led to necrotic damage including skin erosions and crusting, breaks in the skin that resulted in skin infections, and in some cases scarring of the skin. There is an opportunity to improving the effectiveness of laser hyperthermia in a way that would maintain or enhance the therapeutic effect while minimizing or eliminating unpleasant side effects of treatment. SUMMARY OF THE INVENTION

The invention provides methods of administering a non-destructive laser treatment to a subject with a disease condition to improve the disease condition treated.

The invention further provides methods of treating diseases of the skin or other barrier tissues with a non-destructive laser, where the other barrier tissue includes the lining of the mouth, nose, trachea, bronchi, lung, esophagus, stomach, gut. peritoneum, bladder, urethra, penis, prostate, uterus, vagina, arteries, veins or capillaries.

The invention further provides methods for treating a disease by causing the release of significant amounts of heat shock proteins from inside cells through exposing the skin or other barrier tissue to a non-destructive lasertreatment. In the methods of the invention, the temperature of the laser-treated tissue is raised to at least 39 ° C but below 45 ° C. The method of the invention does not involve tissue damage caused by excess heating of the tissue that results in necrosis of more than 1% of the cells in the treated tissue, or the disruption of the normal architecture or normal function of the laser-treated tissue.

In the methods of the invention, the laser operates in a pulsed manner. The pulse duration is about 0.1 to about 200 nanoseconds (ns), about 0.5 to 50 ns, or about 1 to 10 ns. The frequency of the laser is about 1 Hertz (Hz) to about 100 kiloHertz (kHz), about 0.1 to about 20 kHz, about 1 to about 10 kHz; the irradiance of the laser is about 0.1 to 10

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Watt/cm (W/cm ) or about 1 to 4 W/cm . Treatment durations of the laser are about 10 seconds (s) to about 10 minutes (min), or about 30 s to 2 min. Treatment may involve a single treatment or a series of treatments up to about 10. The invention provides methods that can be practiced using any laser that can increase the release of heat shock proteins from within laser treated cells without causing significant heat-induced protein denaturation that in turn causes destruction to the laser- exposed cells or tissues, or to cells or tissues close to the site of laser exposure. Lasers for use in the methods of the invention include emits light in the range of visible light to infrared light, with wavelengths of about 500 nanometers to 3000 nanometers.

Appropriate lasers for the method of the invention can include but are not limited to krypton (416 nanometers (nm)), argon (488 and 515 nm), copper bromide (510 and 578 nm), helium-neon (544, 594 and 612 nm), neodymium-doped yttrium aluminium garnet (532 and 1064 nm), ruby (628 and 694 nm), titanium- sapphire (700-1000 nm), neodymium-doped yttrium lithium fluoride (1047 and 1053 nm), erbium- glass (1540 nm), and holium-doped fluoride (2950 nm). Laser wavelengths for use in the methods of the invention include, but are not limited to 510 nm and 578 nm, 532 nm, 810nm, 1064 nm, 1460, 1540, and 2950 nm. Laser beam sizes for use in the method of the invention include, but are not limited to 1-10 mm, 2-8 mm, 2-7 mm, or 3-5 mm in diameter.

The invention provides methods for contacting a subject with a laser exposure that can be delivered to the body directly or through lenses or fiber optic cables, and that can be delivered either externally or internally via a variety of mechanisms including endoscopes of all types and catheters. The invention provides methods for altering the exposure of the light so that the laser intensity profile is Gaussian or other orthogonal profiles, parabolic, or flat.

The methods of the invention include treating a disease of the barrier tissue of the body, wherein the diseases are associated with abnormal cells having an altered cell constituent consisting of an altered structure that can be considered an antigen or non-self particle. Such cells include premalignant cells with precancerous antigenic changes; malignant cells with tumor antigens; virally infected cells expressing viral antigen or containing viral antigens; bacterially-infected cells with intracellular bacteria that therefore contain bacterial antigens; fungally- infected cells containing fungal antigens; parasitic infected cells containing parasitic antigens, which may or may not be expressed also on the cell surface; and infections of other organisms considered to be cell-wall deficient, bacterial-like organisms such as rickettsia, mycoplasma, and anaplasma.

Genetic abnormalities of particular relevance include pre-malignant and malignant transformation of barrier tissues such as actinic keratosis, squamous cell carcinoma, basal cell carcinoma, melanoma, and bladder carcinoma.

Viral infections of particular relevance include viral warts and herpes. A significant percentage of viral skin or genital warts (mainly caused by specific types of human papillomavirus) are resistant to standard treatments. Even when effective, many standard treatments such as cryotherapy or laser ablation therapy are painful and require multiple treatments. While a number of medications exist to treat herpes virus lesions, many of these are slow-actingand only moderatley potent. Therefore, a non-invasive, non-destructive treatment capable of accelerating healing would mark significant progress in treatment of herpes outbreaks.

Bacterial infections of particular relevance include focalized intracellular infections with MRSA, burkholderia, propionebacterium acnes, and peptic or duodenal ulcers caused by Helicobacter pylori.

Fungal infections of particular relevance include onychomycosis. In this condition, fungal colonies proliferate in the nail bed, particularly in the toenails. This infection is more common in people with suppressed immune systems, which allow them to proliferate. Drug treatment is challenging since the nail makes it difficult for topical agents to penetrate, and systemic drug treatment is prolonged, relatively ineffective, and can have significant side effects.

Parasitic infections of potential relevance include leishmaniasis, a parasite spread by the bite of sand flies. The parasites initially infect macrophages in the skin and successfully evade humoral response. After transforming, they are released into circulation and take up residence in the skin, where infected cells induce chronic inflammation that is characterized by suppression of specific cell-mediated immune responses that could kill the parasite. Drug therapy requires prolonged treatment times and has significant side effects in many people, a problem for military personnel in the middle East where cutaneous Leishmaniasis is endemic.

In the methods of the invention, an increase in a detectable response to treatment leads to the improvement of the disease condition without the occurrence of significant damage to the treated tissue, including the development of fibrosis or scarring.

Improvement can include disease remission, amelioration of symptoms, or decrease in morbidity or mortality.

In the method of the invention, the use of the specific parameters of wavelength, laser pulse, and pulse frequency laser allow for an improvement in the disease condition at a lower treatment irradiance and temperature level in the treated tissue compared to a laser of identical wavelength not operating at the specified pulse duration and pulse frequency. BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a graph showing the relationship between irradiance and exposure time for a range of medically-relevant laser-tissue effects.

Figure 2 is a schematic illustrating the difference in thermal diffusion between continuous wave lasers and short-pulse lasers.

Figure 3 is a schematic showing the common signaling pathways of cellular apoptosis and the role of HSP70 in inhibiting these pathways.

Figure 4 is a schematic illustration two common pathways for heat shock protein release from inside cells.

DETAILED DESCRIPTION OF THE INVENTION

As used herein "treating" a disease in a subject or "treating" a subject having a disease refers to subjecting the subject to a laser exposure, in such a manner that the extent of the disease is decreased or prevented. For example, treating results in the reduction of at least on sign or symptom of the disease or condition. Treatment includes (but is not limited to) administration of an exposure to a laser as described herein subsequent to the initiation of a pathologic event. Treatment can require administration of an agent and/ or treatment more than once.

As used herein, a "condition" includes any abnormality that can occur in a subject including any disease, infection, disorder, tumor, cancer, inflammation, or change in cellular structure and function.

As used herein, "destructive" is understood as causing significant necrosis of the cells in a tissue or any disruption of the tissue itself. As used herein, "non-destructive" is understood as not causing either significant necrosis of the cells in a tissue or any disruption of the tissue itself.

As used herein, "necrosis" refers to the chaotic, uncontrolled, and non- programmed death of a cell or, collectively, of a tissue. Necrosis occurs when irreversible exogenous injury occurs to a cell leading to the severe disruption of the cellular membrane and release of the cellular contents. Necrosis is characterized by a dramatic and often chaotic and disorderly impairment of the cell's ability to maintain homeostasis leading to an influx of water and extracellular ions into the cell, vacuolization of the cytoplasm, breakdown of the cellular DNA, and organelle membrane and cellular membrane rupture. The ultimate breakdown of the cell membrane releases the contents of the cell, including lysosomal enzymes, into the extracellular space. As a result, necrosis often results in inflammatory response. Significant necrosis refers to the number of cells that are killed within a tissue, expressed either as a ratio (percent) of the cells exposed to the laser, as a defined number of cells per laser exposure, or a defined area of cells.

Significant necrosis is uncontrolled cell death of at least 1% of the cells.

As used herein, "apoptosis" refers to the regulated death of a cell or, collectively, a tissue. Apoptosis is often referred to as programmed cell death because it is a genetically-regulated process that involves an orderly and stepwise series of intracellular signaling cascades. It is a normal part of the cell life cycle. Apoptotic cells are characterized by membrane blebbing, cell shrinkage, condensation of chromatin, and fragmentation of DNA followed by rapid engulfment of the corpse by neighboring cells or other phagocytic cells. Unlike necrosis, apoptosis does not result in the significant release of the contents of the cell into the extracellular space and therefore does not trigger inflammatory responses. It leads to resorption of many of the apoptotic cells.

As used herein, "tissue disruption" is understood as the physical separation, fragmentation, removal, or disaggregation of cells within a tissue, or of one layer of tissue from another.

As used herein, "subject" refers to a mammal. A human subject can be known as a patient. As used herein, "mammal" refers to any mammal including but not limited to human, mouse, rat. sheep, monkey, goat, rabbit, hamster, horse, cow or pig. A "non- human mammal," as used herein, refers to any mammal that is not a human.

As used herein "exposure" means treating with a laser for a time useful to the invention. In one embodiment, exposure means to treat with a laser applied in a pulse, wherein the pulse is applied for a particular duration. The range of pulse durations are in the hundreds of picoseconds to hundreds of nanoseconds (for example, about 100, 200. 300, 400, 500. 600, 700, 800, 900 picoseconds, or about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 20, 25, 30, 35. 40, 45, 50, 75, 100. or 200 nanoseconds). It is understood that the actual pulse length will vary somewhat based on the limitations of the laser and the switching rate/ shutter speed. In another embodiment, "exposure" means to treat with a laser of a particular pulse repetition (pulse frequency). Optimal pulse frequencies range from about 1 Hz to about 100 kHz (for example, 0.001, 0.01, 1, 10, 100 kHz), with typical pulse frequencies in the 1, 2, 3. 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50 or 100 kHz frequency. It is understood that the actual pulse frequency will vary somewhat based on the limitations of the laser and the switching rate/ shutter speed. In another embodiment, "exposure" means to treat with a laser of a particular wavelength where the range of wavelengths can range from the visible light to the mid- infrared portion of the electromagnetic spectrum (approximately 500 nm to 3000 nm, for example, 400, 425, 450, 475, 500, 525, 550, 575, 600, 625, 650, 675, 700, 725, 750, 775, 800, 825, 850, 875, 900, 925, 950. 975, 1000, 1125, 1150, 1175, 1200, 1225, 1250, 1275, 1300, 1325, 1350, 1375, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, 2600 2700 2800, 2900, and 3000 nm), and are typically about 500-2000 nm. In another embodiment, "exposing" means to expose a subject to a laser with a particular peak energy, where the range of pulse energy is 1 microjoule to (1 x 10^"6 J) to 1 Joule (for example, 1, 10, 20, 30 40, 50, 100, 200, 300, 400, 500 microjoules. 1, 2, 3, 4, 5, 10, 20. 30, 40, 50, 100, 200, 300, 400 500 millijoules, or 0.6, 0.7. 0.8, 0.9. and 1.0 Joule).

In another embodiment, "exposure" means to treat with a laser of a particular power density or irradiance, where the range of irradiance is 0.1 to 10 W/cm² (for example, about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5. 6, 7, 8, 9, or 10 W/cm ) and are typically about 1-4 W/cm .

In another embodiment, "expose" means to treat with a laser for a particular length of time. The range of exposure times can be about 10 seconds to about 600 seconds (for example, about 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600 seconds).

In another embodiment, "exposure" means to treat with a laser a particular area of the subject. Typical treatment areas are about 1-100 mm in diameter (for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80. 90 and 100 mm²). Treatment may involve exposure of multiple areas of the subject. As used herein, a "laser" refers to an electronic-optical device that emits coherent light radiation. A typical laser emits light in a narrow, low-divergence monochromatic (single-colored, if the laser is operating in the visible spectrum), beam with a well- defined wavelength. In this respect, laser light is in sharp contrast with such light sources as the incandescent light bulb, which emits light over a wide area and over a wide spectrum of wavelengths.

As used herein, a "laser" includes any laser that is currently available or may become available that can provide the appropriate pulse duration, power, and pulse frequency required by the methods of the instant invention. Currently available lasers that can be used in the methods of the invention include, but are not limited to gas vapor lasers, metal vapor lasers, pulse dye lasers, solid state lasers, semiconductor lasers and fiber lasers. Examples of lasers that can provide appropriate pulse duration, power density, and pulse frequency include a copper bromide laser such as the Norseld

DualYellow copper bromide laser (511 and 578 nm) or the Asclepion ProYellow+ copper (511 and 578 nm), a Q- switched neodymium-doped yttrium aluminium garnet (Nd: YAG) laser such as the RMI 15 Q-Switched Diode-Pumped Solid State Laser with an output at either 532 nm or 1064 nm, a Q-switched Alexandrite laser at 755 nm, a Q-switched 810 nm diode laser, a pulsed fiber laser such as the IPG Photonics YLP series ytterbium pulsed fiber laser at 1055-1075 nm, or a nanosecond pulsed fiber laser such as the Nufern NuTx erbium- ytterbium doped 1550 nm nanosecond pulsed fiber laser.

As used herein, a "barrier tissue" is an organized aggregation of different cell types that exist at the boundary between an organ or structure and an internal cavity or between the body and the external environment that surrounds an organism. Internal cavities include but are not limited to those inside the mouth, nose, esophagus, stomach, large and small intestines, peritoneum, trachea, bronchi, lung, bladder, prostate, urethra, penis, uterus, vagina, arteries, veins or capillaries. The main barrier tissue to the outside environment is the skin. Barrier tissues are composed of different layers but essentially are composed of epithelial tissue and connective tissue separated by a basement membrance. The epithelial layer may include a mucosal layer with distinct sets of secretory and immune cells, while the connective tissue tends to be far more diverse and can include glands, muscle tissue, nerves, capillaries, collagen and fat deposits. Instead of a mucosal layer the skin has an outer layer keratinaceous layer called the stratum corneum.

As used herein, a "heat shock protein" refers to a group of proteins that are important to cell protection and whose expression is typically increased when cells are exposed to elevated temperatures or other stress. Heat shock proteins (HSPs) are named according to their molecular weights. For example, Hsp60, Hsp70 and Hsp90 (the most widely- studied HSPs) refer to families of heat shock proteins on the order of 60, 70 and 90 kilodaltons in size, respectively, and there are five major groups of HSPs found in humans: 20-30, 50-60, 70, 90, and 100-110 kDa. Some HSPs, such as HSP70, are found in virtually every organism and its structures are highly conserved across species. The small 8 kDa protein ubiquitin, which marks proteins for degradation, also has features of a heat shock protein.

As used herein, "hyperthermia" refers to a condition of elevated temperature or a process of elevating the temperature in a cell or tissue above normal by exposing the cell or tissue to a source of energy that results in the generation of heat within a cell or tissue or the transfer of heat into a cell or tissue. As used herein, "laser hyperthermia" is the use of a laser to produce heating of cells or tissue. Hyperthermia may be produced by direct exposure of a cell or tissue to the laser or by transfer of heat from an adjacent cell or tissue area.

As used herein, "release" refers to the externalization of substances that are normally resident within the cell or at the cell membrane. Release may occur through an active process or through a passive process using a variety of mechanisms, which may include but are not limited to ion pumps, protein chaperones, lysosomal release, membrane blebbing, gap-junction transfer, osmosis or diffusion. Significant release refers to externalization of at least 10% of any specific population of a specific substance within the cells of the laser exposed tissue

As used herein, "immunogenicity" refers to the ability, for example the ability of an agent, to induce local innate and systemic humoral and/or cell-mediated immune responses in a subject.

As used herein, "immune response" refers to a response made by one or more elements of the immune system of an organism. There are two major classes of immune response, innate immune response, which is a general response to pathogen invasion or tissue damage and is often characterized by the release of antimicrobial proteins, cytokines, chemokines, complement and the triggering of inflammation; and adaptive immune response, which is a more specific response to pathogens or diseased cells based on recognition of the abnormal or non-self nature of these pathogens or cells. Adaptive immunity may take the form of a humoral immune response, characterized by the production of antibodies, and cell-mediated immune response, characterized by the production of cytotoxic agents by specific immune cells. An immune response may include any part of or a combination of these types of responses.

As used herein, "antigen" refers to any molecule that can stimulate an immune response in the body. Antigens are typically foreign substances produced by pathogens such as viruses and bacteria, but also may be abnormal proteins or peptides from host cells whose function is altered or impaired. Antigens may take the form of peptides, proteins, liposaccharides, toxins, DNA or DNA fragments, and RNA or RNA fragments.

As used herein, a "decrease" as it refers to a diminution in the level of a response as defined herein, means a response that is at least about 2-fold (for example about 2, 3, 4, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 1000-fold or more) or at least about 2% (for example, about 2, 3, 4, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 99, or 100%), less than the level of response of an untreated subject, for example a subject that has not been exposed to a laser.

As used herein, a "detectable response" includes a discernable, preferably a measurable level of a response that occurs in a subject that has been exposed to a laser, as described herein, but not in a subject that has not been exposed to a laser. A "response" that is detected includes, but is not limited to, one or more of an increase in cellular apoptosis, a decrease in the level of hyperthermia required to produce a therapeutic response, an increase or decrease in immunogenicity, an increase in the release of HSPs.

As used herein, "measuring" means detecting or determining the amount, for example, an increase in the release of HSPs, an increase in membrane permeability, an increase or decrease in temperature. Measuring is the steps taken to determine if an increase or decrease in a level of the material to be detected. Measuring may indicate a level that is zero or below the level of detection or greater than the linear detection limit of the method used for measuring. Measuring according to the invention is performed in vitro or in vivo, for example in the skin or mucosal layer at the site of laser exposure, in serum or in blood or other biological sample, tissue or organ.

"Measuring" also means detecting a change that is either an increase or decrease in the response (for example an increase or a decrease in cellular necrosis or apoptosis, a decrease in the level of hyperthermia required to produce a therapeutic response, an increase in the release of HSPs, a decrease in the size or mass of diseased tissue, or the death rate from a disease) of a subject to treatment with a laser, according to the methods described herein.

Measuring is performed in a subject wherein said subject has been exposed to a laser. Measuring is also performed in a control subject, for example a subject that has not been exposed to a laser.

Ranges provided herein are understood to be shorthand for all of the values within the range. For example, a range of 1 to 50 is understood to include any number, combination of numbers, or sub-range from the group consisting 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50.

Unless specifically stated or obvious from context, as used herein, the term "or" is understood to be inclusive.

Unless specifically stated or obvious from context, as used herein, the terms "a", "an", and "the" are understood to be singular or plural. As used herein, "about" is understood to be relative to the amount of variance typically tolerated in the specific assay, method, or measurement provided. For example, "about" is typically understood to be within about 3 standard deviations of the mean, or two standard deviations of the mean. "About" can be understood as a variation of 20%, 15%, 12%, 10%, 8%, 5%, 3%, 2%, or 1%, depending upon the tolerances in the particular art, device, assay, or method.

The recitation of a listing of chemical groups in any definition of a variable herein includes definitions of that variable as any single group or combination of listed groups. The recitation of an embodiment for a variable or aspect herein includes that embodiment as any single embodiment or in combination with any other embodiments or portions thereof.

The invention provides a method of treating diseases of the skin and other barrier tissues with a non-destructive laser. The invention improves laser hyperthermia treatment of diseased tissues by increasing the number of diseased cells in a treated tissue undergoing apoptosis as a result of a thermal dose, allowing for a reduction in the thermal dose required to effectively treat a diseased tissue.

Without wishing to be bound by mechanism, it is suggested that laser treatment produces non-destructive intracellular stress within cells either directly exposed to the laser or in close proximity to the exposure sufficient to stimulate the release of heat shock proteins (HSPs) contained within these cells. This HSP release effects diseased cells more than normal cells and increases the vulnerability that diseased cells have to the effects of hyperthermia compared to normal cells. This change increases the apoptotic potential of a laser hyperthermia dose and enables medically effective treatment to be given at lower laser irradiance, lowering the temperatures inside treated tissues. This reduction in irradiance means that treatment can be given while avoiding significant necrosis to treated tissues or disruption of the tissue. As a practical result, medically effective laser hyperthermia can be given without causing pain, necrosis, disfigurement of the treatment site, or scarring from treatment.

These effects require a laser emitting light at a specific combination of wavelength, pulse duration, pulse frequency pulse energy and irradiance. Lasers with the appropriate combinations of wavelength, pulse duration, pulse frequency pulse energy and irradiance will result in therapeutically more effective hyperthermia at a given dose than lasers that do not have the appropriate combination of parameters.

Principles of Photothermal Laser- Tissue Interactions

The photothermal or heating effects of lasers are based on the conversion of laser light energy into heat energy within a cell or tissue. This energy conversion is mediated by chromophores, which are chemical compounds capable of selective light absorbance. Once the laser energy is converted into heat via the chromophore, heat begins to dissipate into the surrounding tissue. When heat is generated by the chromophore faster than it can be dissipated to the surrounding tissue, the result is an increase in the temperature within a local region. This condition is called thermal containment. Thermal containment results in the development of a local temperature gradient. These gradients are highly predictable and reproducible, making it possible to carefully adjust the amount of heat generated in the skin.

Photothermal effects are a result of total thermal dose and not solely of the temperature, and there is an inverse relationship between the temperature and the duration of exposure needed to produce similar thermal effects in tissue. This relationship is illustrated by Figure 1. The temperature level produced in the tissue over a unit of time is a function of the power produced by the laser. A standard measure of laser power that controls for the relative size of the beam is power density or irradiance, expressed as Watts/m² or Watts/cm².

Under thermal containment, a cell or a tissue can be progressively heated to a supraphysiological level, eventually leading to significant and irreversible thermal damage. Photothermal destruction of cells and tissues first occurs when the proteins within a cell are altered, resulting in a loss of cellular function and resulting in

uncontrolled cell death or necrosis. Alteration occurs when the kinetic energy caused by heat overcomes the weak hydrogen bonds and van der Waals interactions that help maintain the three-dimensional structure of proteins. Exposure of tissues to lasers of sufficient power can result in necrosis not of diffuse populations of cells within the tissue, but of the entire laser-exposed tissue. At high enough power levels tissues can be coagulated or carbonized by a laser.

Control over thermal diffusion can be improved by using lasers that feature very short pulses of laser light. The size of the target for absorption of laser light is a function of the thermal relaxation time, the time span it takes for the majority of heat to diffuse from a target. The smaller the size of the absorption target, the shorter is its relaxation time. Micro vessels in the skin have a thermal relaxation time on the order of 10^" seconds, while for intracellular structures such as melanocytes this is on the order of 10^"8 seconds. When the duration of a laser pulse is shorter than the relaxation time of the target, heat is confined to this target, and the user gains more control over the diffusion of the heat in the tissue. The shorter the laser pulse, the smaller the thermal target, and the more confined thermal diffusion within the tissue becomes. Thus, while continuous wave lasers will release a significant amount of heat into surrounding tissues, often resulting in uncontrolled thermal effects in these tissues, very short laser pulses on will confine heating effects to the cellular and intracellular level, resulting in effective confinement of the thermal effects within the targeted tissue (Figure 2).

At very short laser pulses heating occurs at a very small scale (i.e., at an intracellular level), even modest amounts of energy can cause chromophore heating to very high temperatures, well above 100° C. When this occurs, water in the cell or tissue next to the chromophore is heated more rapidly than it can diffuse the heat, and the water experiences a rapid phase change into a gas, referred to as a phase explosion. This phase transition results in the generation of extremely hot vapor bubbles inside the cell. This is called microcavitation. The subsequent rapid expansion of these vapor bubbles can cause disruption of cell organelles or cell membranes, leading to the death of the cell. On a larger scale, this effect can cause the rapid vaporization or disruption of tissue, a process called photoablation. Photoablation can also occur when the laser wavelength is highly absorbed by water. In these cases water is the primary chromophore, and photoablation can occur even without laser pulsing, by heating water to the point of phase explosion.

Cell necrosis can also result from the photochemical effects of lasers, which occur when laser energy catalyzes a chemical process that is toxic to the cell. One of the major ways lasers can cause cell and tissue destruction through photochemical effects is the generation of reactive oxygen or nitrogen species. The precise mechanisms of action are not understood, but it is hypothesized that generation of free radicals occurs when the energy of a photon from a laser exceeds the energy needed to remove an electron from a molecule. The initial cellular damage may be due to the local formation of hydroxyl or other reactive radicals that may then generate longer lived organic radicals including peroxy- or alkoxy- radicals. Typical targets for this kind of laser damage are cell membranes, mitochondria, nitric acid complexes, proteins and lipids.

Free radicals damage cellular DNA. cell membranes, alter intracellular and extracellular redox pathways and cause denaturation of proteins within the cell. While cells have a variety of mechanisms for defending themselves against radical oxygen or nitrogen species damage, generation of larger amounts of reactive oxygen or nitrogen species can exceed the ability of the cell to respond. When the generation of free radicals within or outside of a cell exceeds the ability of the cell to prevent or repair the damage, the cell is irreversibly damaged and in most cases apoptosis is induced.

Another photochemical effect is the direct damage of cellular DNA by laser light. In some cases absorption of energetic photons can cause breaks in the DNA structure, leading in some cases to irreversible cell damage and subsequent apoptosis. In general, destructive photochemical effects are generated by lasers emitting light in the ultraviolet UV spectrum.

Cellular necrosis from photothermal or photochemical effects may occur immediately upon exposure to the laser or over a longer period of time depending on the power of the laser and the energy of the pulse used. Tissue disruption from photothermal or photoablative effects is typically immediate.

Measurement of the concentration of necrotic cells in a particular tissue or culture is routine in the art. Methods and kits are known in the art to detect necrosis. The number of cells undergoing necrosis can be readily scored and expressed as a percentage of cells exposed to the laser. Practitioners in the art are able to easily distinguish between necrotic death and apoptotic death of cells

Necrotic cells can be detected by flow cytometry techniques, such as the addition of the nucleic acid stain PI, which binds to DNA or RNA but cannot permeate cell membranes and therefore is visible under fluorescence only if the cell membrane has been compromised, or stains such as propidium iodide or 7-AAD that discriminate cells which have lost membrane integrity. In addition, they can be visualized optically using standard staining and microscopy techniques.

Measurement of tissue disruption is routine in the art. Disruption can be assessed visually by means of naked eye inspection, use of magnifying glasses, biopsying of the tissue, preparation of slides and microscopic inspection of histology. Staining may be used to help differentiate tissue types in the slide.

The method of this invention utilizes laser irradiation of tissue that generates a therapeutic hyperthermia in the treated tissue but avoids significant cellular or tissue necrosis or any tissue disruption. Preferably less than 1% of cells are uncontrollably damaged upon laser exposure using the methods of the invention and the tissue is not disrupted in any way. In one embodiment, cellular necrosis or tissue disruption is prevented by limiting the increase in temperature in the cells and/or tissues exposed to the laser in the methods of the invention to below the levels below the critical thresholds that lead to necrosis, In another embodiment, significant necrosis or tissue disruption is prevented by limiting the pulse duration of the laser to longer than 100 picoseconds. In another embodiment, significant necrosis or tissue disruption is limited by limiting the laser wavelength to above 500 nm and below 3000 nm. In another embodiment, significant necrosis or tissue disruption is prevented by limiting the irradiance to below 10 W/cm².

The method of the invention relates to using lasers to produce apoptosis rather than necrosis in treated tissues. Hyperthermia below the level of necrotic damage has been demonstrated to have a significant therapeutic effect on certain diseases by inducing apoptosis in the diseased tissue.

Measurement of apoptosis can be detected by practioners of the art using flow cytometry techniques. For example, apoptotic cells show an increased uptake of the vital dye HO342 compared to live cells due to a changes in membrane permeability. Apoptosis can be measured using a number of other assay-based approaches including measurement of DNA fragmentation, membrane phospholipid changes, interleukin-lbeta converting enzyme-like protease activation, or nucleosomal fragmentation by DNA agarose gel electrophoresis. Finally, apoptosis can be detected through visual means such as changes in cell morphology.

Heat Shock Response to Hyperthermia

The normal cellular response to supraphysical levels of heat as well as other cellular stresses such as hypoxia or toxins, involves a number of coping processes including the mobilization and increased production (overexpression) of heat shock proteins, which provide valuable cellular survival functions such as protein maintenance, folding, chaperoning and degradation, blocking apoptotic signaling pathways, and, when expressed on the surface of the cell, stabilizing the cell membrane and assisting with cell signaling and receptor function. This activation and overexpression of HSPs is known as the heat shock response. The 70 kDa inducible HSP70 (also known as HSP72) is a key HSP in heat shock response.

The baseline level of intracellular HSP70 varies between cell types. In general, cells that play key roles in protecting the body from environmental stress have higher baseline levels of HSP70. High levels of baseline HSP70 are found in the eye, brain, heart, kidney, and the skin. Specific cell types in these tissues known for high levels of baseline HSP70 include glial cells, arterial endothelial cells, renal epithelial cells, and keratinocytes.

Diseased cells are characterized by the presence of higher levels of oxidative, hypoxic, or toxic stress and a higher concentration of abnormal and damaged proteins. This in part is what makes them more vulnerable to hyperthermia. In order for these cells to survive, they also express higher concentrations of HSPs, including HSP70, than their normal counterparts. This is the case with genetically abnormal cells and with many types of infected cells. The presence of higher concentrations of HSPs enables diseased or abnormal cells to refold or dispose of abnormal proteins that would otherwise often trigger cell death. In particular, HSP70 plays such a role in refolding abnormal proteins in diseased cells. HSPs also serve to block apoptotic signals generated inside stressed or diseased cells. Several key signaling pathways of apoptosis in cells are inhibited by HSPs, particularly HSP70 (Figure 3). An increase in internal levels of HSP70 increases the ability of stressed cells to resist apoptosis.

The apoptotic effect of conventionally delivered laser hyperthermia is partly mitigated by the higher concentration of protective HSPs such as HSP70 inside diseased cells. The therapeutic effect of laser hyperthermia could be improved by removal of HSPs from diseased cells. This goal can be accomplished by a modification in the parameters of the laser used to treat the tissue.

Laser Thermoacoustic Stress

Removal of HSPs from target cells can be accomplished through the use of ultrashort (nanosecond and picosecond duration) laser pulses repeated at high

frequencies, preferably in the kilohertz range. These parameters add a dimension of thermoacoustic stress to laser hyperthermia that stimulates the rapid release of HSP70 from inside of laser treated cells.

Thermoacoustic stress is the result of differential thermal expansion of laser treated tissue. Continuous wave laser irradiation of tissue under thermal confinement results in a constant flow of heat out of the treated tissue, producing a temporally consistent thermal gradient. However, if the laser light is pulsed, significant thermal discontinuities occur between the focus of laser absorption and the surrounding tissue, resulting in different rates of thermal expansion and thus pressure differences between the chromophore absorbing laser light and the surrounding tissue. The pressure difference generates an acoustic wave that propogates at a much slower rate than that of heat dissipation. For the most part, at longer pulse durations these acoustic waves are insignificant and their effect is further diminished by harmonics and acoustic scattering in the tissue. However, as the duration of a laser pulse becomes much shorter than the time it takes for the acoustic pulse to be propogated, a condition of "stress confinement" is reached, where the generation of acoustic wave becomes significant. The magnitude of acoustic stress increases as laser pulses shorten. Thermoacoustic stress can be accentuated when the depth of absorption of the laser light is decreased, hence decreasing the volume of tissue where the thermoacoustic effect is propogated. In human tissues with laser pulses in the visible to mid-infrared range, thermoacoustic effect becomes significant at pulse durations below 100 nanoseconds. Under conditions of stress confinement, the amplitude of the acoustic wave can also be increased by increasing the energy of the laser beam. With a continued decrease in laser pulse duration,

thermoacoustic effects can eventually lead to microcavitation and subsequent cell damage.

A sustained exposure of tissue to ultrashort pulses at irradiances below the level of microcavitation will result in the transmission of acoustic waves through the tissue, perturbing the laser-treated cell and its intracellular membranes. This effect is enhanced by the use of high pulse frequencies. Significantly, sufficient perturbation of the cells may lead to biological effects not produced by long-pulse or continuous wave lasers. In particular, coupling hyperthermia with a thermoacoustic effect can induce rapid release of HSP70 from cells.

A number of investigators have shown that the application of heat can lead to release of large quantities of HSP70 in milieu outside of viable cells. A number of hypotheses for the mechanism of release have been proposed, including transport by lipid rafts (Broquet et al. 2003), small vesicles, secretory granules or through an

endolysosomal compartment. The main mechanisms of HSP70 release from cells are shown in Figure 4.

Most of these experiments involved conductive heating of cells in a water bath. Under these conditions, released HSP70 represented only a fraction of the total cell content of HSP70 and occurred slowly, over a period of hours from the initial heat shock. In general, heating cells with lasers has shown the ability to increase HSP

overexpression, not release. An exception to this showed that exposures of 1-2 minutes with a visible light (511/578 nm), nanosecond pulsed, high pulse frequency laser caused rapid release of HSP70 in a laser dose-dependent manner. Subsequent histology demonstrated that these parameters of laser irradiation induced this effect without causing and damage to the cells within the tissue or disruption of the tissue itself (Patent

Application WO/2009/044272, which is incorporated herein in its entirety). Recent work showed the ability of infrared lasers to cause release of HSP70 together with ceramide, a common constituent of lipid rafts and lysosomes, which provides support for some of the mechanisms of release described above.

Further experimental work has shown that nanosecond pulsed, kilohertz frequency visible light (532 nm) lasers can cause the release and subsequent migration of HSP70 from skin tissues within the first hour after laser treatment, and that with sufficient dose the entire quantity of HSP70 is essentially driven out of the tissue. This unusual response to ultra-short frequent pulses of laser light inducing thermoacoustic effect can significantly improve therapeutic effect of laser hyperthermia and make it a more palatable treatment regimen for patients.

Enhancement of Laser Hyperthermia

Triggering the release of HSP70 from diseased cells through the use of ultrashort, high frequency pulsed lasers improves the effect of hyperthermia in two different ways. First, the intentionally triggered release of HSPs from diseased cells makes the cells more vulnerable to heat stress. Hyperthermia can induce programmed cell death or apoptosis in diseased cells through a variety of means including proliferating abnormally- folded proteins, inducing nuclear damage and destabilizing the cell membrane. In addition, it has been demonstrated that hyperthermia can trigger non-traditional, caspase-mediated apoptotic pathways within abnormal cells. In infected cells, hyperthermia can also trigger differential apoptosis between normal and diseased cells due in part to these cells significantly higher expression of pro-apoptotic proteins. Since many of these

pathways— accumulation of abnormal or unfolded proteins, membrane instability, and apoptotic signaling are mitigated by the presence of HSP70, intentionally triggered removal of HSP70 from cells will make diseased cells increasingly vulnerable to hyperthermia-induced apoptosis, increasing the death rate of these cells in response to.

Second, release of HSP70 from diseased cells increases the immunogenicity of diseased cells. Heating of abnormal cells typically upregulates HSP expression genes, resulting in a significant increase of HSPs within heat shocked tissues after 6-12 hours. When heat shock occurs in diseased cells, significant amounts of this new HSP70 are expressed on the surface of the cell, making the cell more vulnerable to detection and destruction by immune cells.

Overexpression of HSP70 in response to stress is mediated by the HSFl protein. HSFl exists as an inactive monomer in a complex with HSP40/HSP70 and HSP90. Upon stress, such as an elevated temperature, HSFl is released from the chaperone complex and trimerizes. HSFl is then transported into the nucleus where it is hyperphosphorylated and binds to DNA containing heat shock elements. The presence of HSP70 inside the cell inhibits the activity of HSFl. Therefore, cells that already possess high baseline levels of HSP70 do not tend to overexpress HSP70 as much as cells that possess relatively small concentrations of HSP70.

The triggered release of HSP70 from the cells binds locally. This increases the amount of membrane-expressed HSP70, enhancing the immunogenicity of cells surviving hyperthermia, which are more vulnerable to identification and destruction by immune cells. By making diseased cells more immunogenic, the opportunity for effective treatment of the disease is increased.

The ability to significantly improve the dose-response of laser hyperthermia will permit an adjustment to the treatment approach, specifically lowering the temperature needed for medically effective treatment. This has obvious and important benefits. First, lowering the temperature decreases the likelihood of thermal damage to the treatment site including necrotic damage and tissue disruption. This will decrease the potential for post- treatment wounding (erosional lesions and crusting) and for long-term scarring. Second, it will enable medically effective treatment to be delivered painlessly. In the skin, sensations of pain in response to laser treatment delivered longer than a few seconds set in above approximately 43° C. It is therefore difficult to provide a sufficient hyperthermia dose in a short period of time to the diseased tissue without causing significant pain to the treated patient. Decreasing the thermal stress on the tissue to relieve pain sensations can significantly change the thermal profile within the treated tissue, resulting in insufficient hyperthermia doses and the failure of treatment or the need to repeat treatment. However, by lowering the temperature required for effective therapy, treatment can take place below the threshold of pain and laser doses can be delivered consistently without the need to adjust for patient discomfort. EXAMPLES

Example 1: Painless Delivery of High Doses of Laser Energy

Subjects in previously published studies of laser hyperthermia of barrier tissue diseases were treated with 1064 nm lasers operating in continuous wave mode. These subjects typically received a maximum of up to 240 J/cm dose at an irradiance of around 20 W/cm².

An experiment was performed to see if significant laser doses could be delivered to the human skin over relatively short periods of time to produce significant treatment doses while avoiding pain or tissue damage. Five subjects with Fitzpatrick skin types V and VI were treated with a laser (Q-YAG 5, Palomar Medical Technologies) operating at the 1064 nm wavelength and emitting 3 nanosecond pulse duration at a 10 Hz pulse frequency. The laser spot on the skin was 8 mm. Each subject received between 10-20 separate exposures on the skin of the back. Exposure time for each treatment was a maximum of 120 seconds. Irradiance levels of the laser ranged between 0.52 W/cm² and 3.66 W/cm . All subjects were monitored for visible signs of skin damage and for discomfort from laser treatment. Criteria for skin damage included blistering, bruising, crusting, edema, hyperpigmentation, hypopigmentation, or inflammation. Criteria for discomfort included skin hotness, pinprick/needle sensation, sharp pain or other.

AU subjects tolerated a maximum of 3.66 W/cm' for 120 seconds, resulting in a total dose of 444 J/ cm . This dose represents about 2-4 times the laser dose delivered in the 532 nm treatment experiments. None of the subjects expressed discomfort to treatment, but all of them experienced sensations of intense skin warmth. Two subjects showed transient skin discoloration that resolved within minutes. No skin damage was noted with any of the exposures at the time of treatment, one hour after treatment or two days after treatment.

Example 2: Treatment of Actinic Keratosis

Actinic keratosis (AK) is a dry, scaly skin lesion that results from long-term solar damage. AK predominantly affects people with lighter skin types, predominantly

Fitzpatrick Skin Types I-II. Darker- skinned people rarely develop AK. AK exists toward one end of a continuum of genetic abnormalities that culminates in squamous cell carcinoma. Most dermatologists consider that AK constitutes the initial lesion in a disease continuum that can progress to invasive squamous cell carcinoma (SCC).

Commonly- found genetic mutations in AK cells include alterations to p53, which are increasingly prevalent at more advanced stages of cancerous transformation in keratinocytes.

Six study subjects ages 40-70 and diagnosed with AK are enrolled in a treatment study. Subjects have Fitzpatrick skin types I or II and are diagnosed with

nonhyperkeratotic AK lesions of mild thickness and display at least one spot with approximate size of 3-6 mm in diameter situated on the forearm. Subjects are treated with a modified cosmetic laser (Q-YAG 5, Palomar Medical Technologies, Burlington, MA) using a setting and exposure designed to raise the temperature within the AK lesion without causing pain or immediate tissue damage. The study includes two parts: a safety portion and a treatment portion. Each subject is first treated to a series of laser exposures of progressively higher power to establish a safe and tolerable dose on the skin of the forearm for each subject. This dose is then applied to an AK lesion on the opposite arm. The laser used in this study has been modified within its FDA licensure to operate at average power levels below 1 Watt, significantly below the power levels typically used with this laser. The fixed parameters of laser irradiation in this study are: dual wavelength of the same energy at 532 nm and 1064 nm, 3 ns pulse duration, 10 Hz periodicity, 2 minute exposure time, and a laser target spot size of 8 mm in diameter. The variability in the study is the power of the laser. This is adjusted until a maximum safe level is established for each subject. The skin temperature of the subject is measured during the exposure. A safe level of laser exposure here is defined as that which causes no pain to the subject or sign of skin damage within one hour of completion of the exposure.

Maximum safe irradiance was found to be in the range of 1.0-1.2 W/cm . Skin temperatures at this irradiance were below 43° C. The site of laser treatment is shaved in advance of laser application. An aqueous gel (used to enhance dissipation of heat from the skin) is placed on the site of the laser exposure immediately before each laser treatment.

Following completion of the safety study portion, the investigator treats one AK lesion on the arm opposite to the one used for the safety study for two minutes with the laser, using the maximum safe irradiance (1.0-1.2 W/cm²) identified in the safety portion of the study. Subjects returned after two weeks for a second visit. At this visit the lesions were examined by the PI. All 6 patients showed at least partial resolution of the lesion. None of the subjects showed or reported any indication of skin disruption or damage including inflammation, edema, crusting, erosion, fluid secretion, peeling, or scarring. At the second visit the laser treatment regimen was repeated. All subjects returned in another two weeks for a final assessment that showed resolution of the lesions. Again, none of the subjects showed or reported any indication of cellular necrosis or tissue disruption.

Example 3: Treatment of Persistent Skin Warts

Skin warts (verruca vulgaris) are chronic infections by human papillomaviruses (HPV) of the keratinocytes in the epidermal layer of the skin. The HPV family contains a large number of different genotypes. Most skin warts are caused by HPV types 1, 2 and 3. Genital warts are caused mostly by types 6 and 11. Types 16 and 18 are linked to development of cervical cancer. HPV initially infects the keratinocytes at the basal layer of the epidermis, and during this stage the virus carefully regulates expression of its E6 and E7 protein in the lower epithelial layers to drive keratinocytes into S -phase, which creates an environment that is conducive for viral genome replication and cell proliferation. As keratinocytes differentiate in the upper layers of the epidermis, the virus hijacks the cell's DNA synthetic process and produces additional proteins to rapidly proliferate viral copies. Immune evasion is built into the pathogenesis of HPV infection frequently resulting in chronic infection of the skin. About half of all warts that are treated by first line therapies prove to be resistant or recurrent, and often must be subsequently treated by medical professionals.

Fifty patients with warts on the soles of the feet (plantar warts) are enrolled in a study. All subjects received preparation of the skin bed for irradiation by paring of the wart using a scalpel to remove hyperkeratotic skin just to the point of bleeding. Subjects then receive either conventional cryotherapy treatment following conventional medical practices or treatment with a laser with the following operating parameters: 1064 nm wavelength, 10 ns pulse duration, 30 KHz pulse frequency, and irradiance of 3.5 W/cm². Spot size of the laser on the skin is 5 mm. Warts larger than 5 mm in size are treated at four equal intervals around the boundary of the wart. Time of each exposure is 1 minute.

Subjects receive a maximum of three treatment sessions, each 2 weeks apart. All subjects are monitored for pain responses and skin damage in response to treatment as well as efficacy of treatment.

AU patients treated with cryotherapy experience stinging or burning pain in treatment. Typical response to treatment involves blistering of the treatment site and sloughing of the necrotic skin. One subjects experiences local infection of the

cryotherapy site that is treated with topical antibiotics. After the third treatment, 20 of 25 subjects experience resolution of the wart.

Subjects in the laser treated site experience no pain on treatment and no necrotic changes in the skin. Three subjects show some signs of inflammation in the wart bed characterized by a slight redness. Half of the subjects experience wart disappearance after a single treatment. Ten additional subjects experience disappearance of the wart after completion of all three treatments. All subjects are followed for an additional six months after the completion of the three treatment sessions to monitor for wart recurrence. Wart recurrence occurred in one of the cryotherapy-treated subjects and in one of the laser- treated subjects.

Example 4: Treatment of Cutaneous Leishmaniasis

Cutaneous leismaniasis is a parasitic infection that results from the bite of a sand fly. The life cycle of the leishmania protozoan is complex and can cause different expressions of disease, but a common one is the development of cutaneous nodules at the site of the sand fly bite. The disease begins as an erythematous papule. If not treated, the papule increases in size and becomes a nodule. It eventually ulcerates and crusts over.

Treatment of leishmaniasis is limited and generally takes the form of pentavalent antimonials. This typically includes meglumine antimoniate (Glucantime) and sodium stibogluconate (Pentostam) in a dose of 20 mg per kg per day for 20 days. While effective, these drugs take extended time to bring healing, which generally occurs within two months, and are givem either intravenously or intramuscularly, a mayor problem US military in Iraq.

In this study, 30 US military service personnel diagnosed with cutaneous leishmaniasis are randomized to one of two study groups. Subjects qualified to be treated have nodular but not ulcerative cutaneous disease. One group receives standard drug therapy with either Glucantime or Pentostam (20 mg per day for 20 days), while the other group receives the same treatment, combined with cutaneous treatment of the

leishmaniasis nodules with a laser with the following operating parameters: 1064 nm wavelength, 10 ns pulse duration, 10 KHz pulse frequency, and irradiance of 3.75-5.0 W/cm² depending on skin phototype. Laser beam diameter is 1 cm. Subjects with skin phototypes of I-II receive 5.0 W/cm², type III- IV receive 4.5 W/cm², and types V-VI receive 3.75 W/cm². All non-ulcerated leishmania nodules are treated with a series of 2 minute exposures to cover the surface of the infection but without overlap. Treatment is repeated once per week at day 0, 7 and 14 for a total of three treatments over the course of therapy (20 days). Both groups are observed over five more weeks to assess the time of resolution for each cutaneous nodule, as well as success rate for systemic clearance of the disease. The appearance of each nodule is noted in digital images of the nodules are taken. Treatment failures from each group are documented at the end of two months. Outcomes for the study show both groups show statistically equivalent responses to therapy by the end of two months, with 13 of 15 subjects showing recovery in the drug only group and 15 out of 15 in the drug + laser group. However, in the drug + laser treatment arm, time of resolution is faster. Most subjects begin to show improvement in the nodules by day 7; 75% (12/15) subjects showing significant healing by day 14 and 87% (13/15) showing resolution by the end of drug therapy. In the drag only group, only 50% show resolution by the end of therapy. In addition, the level of skin scarring from the nodules is assessed as significantly less in the drug + laser group. There are no significant side effects in either group, and laser treatment is tolerated without pain or discomfort by all subjects.

Example 5: Treatment of Non-Metastatic Bladder Cancer

Bladder cancer typically first develops in the epithelial cells that line the bladder cavity. In its early stages it is confined to this layer and is most amenable to treatment with chemotherapy or immunotherapy. In this study. 60 subjects diagnosed with bladder cancer meeting the following criteria-T0,N0,M0. Ta,N0,M0, or Tl,N0,M0-are randomized into two study groups. The first group receives surgical removal of the lesion through transurethral resection. The second group receives laser treatment of the lesion by cystoscopy. Subjects receiving this treatment have their bladders filled and fluorocoxib compounds are introduced to identify the locations and extent of the tumor lesions via fluorescent imaging (Udin et al. 2010). Lasers used in treatment operate at 1550 nm wavelength, 10 nanosecond pulse, 10 kHz pulse frequency with a 1 cm diameter laser beam spot. The laser is delivered to the bladder lining through a fiberoptic interface that ensures a flat top beam profile at the target. Lesions greater than 1 cm in diameter are treated with a series of exposures that systematically cover the whole lesion. Treatment per exposure is 30 seconds with an irradiance of 2.0 W/cm².

Subjects from both groups are inspected two weeks later by cystoscopy to assess healing and the presence of tumor. Visual inspections of the surgical and treatment sites are performed followed by flurorocoxib detection of active lesion. All patients show clearance of all lesions after a single treatment of either surgery or laser treatment. There are no complications in either group.

Claims

CLAIMS: What is claimed is:

1. A method of treating diseases of the skin or other barrier tissues of the body comprising: exposure of a disease-affected area of the skin, mucosal layers, blood vessel walls, or other barrier tissues of the mammal to a non-destructive pulsed laser beam,

wherein a pulse frequency of the pulsed laser beam is from about 1 Hz to about 100 kHz, wherein a pulse duration of the pulsed laser beam is from about 0.1 nanoseconds to about

200 nanoseconds,

wherein an irradiance of the pulsed laser beam during the pulse duration is from about 0.1 W/cm² to about 10 W/cm²,

wherein a duration of the exposure is from about 10 s to about 600 s, and

wherein the exposure increases a temperature in tissue adjacent to the exposed portion of the skin, mucosal layers, blood vessel walls, or other barrier tissues to a temperature from 39⁰C to about 45⁰C.

2. The method of Claim 1 ,

wherein the exposure is repeated up to about 10 times.

3. The method of Claim 1,

wherein a diameter of the laser beam is from about 1 mm to about 100 mm.

4. The method of Claim 1,

wherein a wavelen ¹gOt¹-h of the laser beam is from about 500 nm to about 3000 nm.

5. The method of Claim 1,

wherein the laser beam is applied to the exposed portion of skin or other barrier tissues directly or through lenses or fiber optic cables, and is applied on the outside of the body or internally using additional devices such as endoscopes and catheters.

6. The method of Claim 1,

wherein a laser producing the laser beam is a diode laser or a fiber laser.

7. The method of Claim 1,

wherein an intensity profile of the laser beam is Gaussian, orthogonal, parabolic, or flat top.

8. The method of Claim 1,

wherein the diseases are associated with abnormal cells having an altered cell constituent consisting of an antigen or non-self particle altered structure, including premalignant cells with precancerous antigenic changes; malignant cells with tumor antigens; virally infected cells expressing viral antigen or containing viral antigens; bacterially infected cells with intracellular bacteria containing bacterial antigens, including mycobacteria infections within cells, including Mycobacterium tuberculosis atypical mycobacteria, and Mycobacterium leprae; fungally infected cells containing fungal antigens; parasitic infected cells containing parasitic antigens, which may or may not be expressed also on the cell surface; and infections by cell-wall deficient bacterial-like organisms including rickettsia, mycoplasma, and anaplasma.

9. The method of Claim 1,

wherein the diseases include actinic keratosis, lichen planus, squamous cell carcinoma, basal cell carcinoma, melanoma, Merkel cell carcinoma, mycosis fungoides, Kaposi's sarcoma, lymphomatoid papulosis, Sezary's syndrome, skin and genital warts, infections by Herpes simplex virus types 1 and 2, infections by Herpes zoster, molluscom contagiosum, peptic or duodenal ulcers due to Helicobacter pylon, skin infections due to MRSA, burkholderia, Haemophilus ducreyi or propionebacterium acnes, donovanosis, sporothrix schenkii, mycetoma, blastomycosis, onychomycosis, tinea pedis, tinea capitis, trichophyton rubrum, or leishmaniasis.

10. The method of Claim 1,

wherein the disease-affected area comprises at least a part of a lesion.

11. The method of Claim 1,

wherein the barrier tissues include lining of the mouth, nose, trachea, bronchi, lung, esophagus, stomach, gut, peritoneum, bladder, urethra, penis, prostate, uterus, vagina, arteries, veins or capillaries.

12. A use of a non-destructive pulsed laser beam to induce a release of heat shock proteins in a mammal having a disease of the skin or other barrier tissues of the body, comprising:

exposure of a disease-affected area of the skin, mucosal layers, blood vessel walls, or other barrier tissues of the mammal to the non-destructive pulsed laser beam,

wherein a pulse frequency of the pulsed laser beam is from about 1 Hz to about 100 kHz, wherein a pulse duration of the pulsed laser beam is from about 0.1 nanoseconds to about 200 nanoseconds,

wherein an irradiance of the pulsed laser beam during the pulse duration is from about 0.1 W/cm² to about 10 W/cm²,

wherein a duration of the exposure is from about 10 s to about 600 s, and

wherein the exposure increases a temperature in tissue adjacent to the exposed portion of the skin, mucosal layers, blood vessel walls, and barrier tissues to a temperature from 39⁰C to about 45⁰C.

13. The method of Claim 12,

wherein the exposure is repeated up to about 10 times.

14. The method of Claim 12,

wherein a diameter of the laser beam is from about 1 mm to about 100 mm.

15. The method of Claim 12,

wherein a wavelength of the laser beam is from about 500 nm to about 3000 nm.

16. The method of Claim 12,

wherein the laser beam is applied to the exposed portion of skin or other barrier tissues directly or through lenses or fiber optic cables, and is applied on the outside of the body or internally using additional devices such as endoscopes and catheters.

17. The method of Claim 12,

wherein a laser producing the laser beam is a diode laser or a fiber laser.

18. The method of Claim 12,

wherein an intensity profile of the laser beam is Gaussian, orthogonal, parabolic, or flat top.

19. The method of Claim 12,

wherein the diseases are associated with abnormal cells having an altered cell constituent consisting of an antigen or non-self particle altered structure, including premalignant cells with precancerous antigenic changes; malignant cells with tumor antigens; virally infected cells expressing viral antigen or containing viral antigens: bacterially infected cells with intracellular bacteria containing bacterial antigens, including mycobacteria infections within cells, including Mycobacterium tuberculosis atypical mycobacteria, and Mycobacterium leprae; fungally infected cells containing fungal antigens; parasitic infected cells containing parasitic antigens, which may or may not be expressed also on the cell surface; and infections by cell-wall deficient bacterial-like organisms including rickettsia, mycoplasma, and anaplasma.

20. The method of Claim 12,

wherein the diseases include actinic keratosis, lichen planus, squamous cell carcinoma, basal cell carcinoma, melanoma, Merkel cell carcinoma, mycosis fungoides, Kaposi's sarcoma, lymphomatoid papulosis, Sezary's syndrome, skin and genital warts, infections by Herpes simplex virus types 1 and 2, infections by Herpes zoster, molluscom contagiosum, peptic or duodenal ulcers due to Helicobacter pylori, skin infections due to MRSA, burkholderia, Haemophilus ducreyi or propionebacterium acnes, donovanosis, sporothrix schenkii, mycetoma, blastomycosis, onychomycosis, tinea pedis, tinea capitis, trichophyton rubrum, or leishmaniasis.

21. The method of Claim 12,

wherein the disease-affected area comprises at least a part of a lesion.

22. The method of Claim 12,

wherein the barrier tissues include lining of the mouth, nose, trachea, bronchi, lung, esophagus, stomach, gut, peritoneum, bladder, urethra, penis, prostate, uterus, vagina, arteries, veins or capillaries.

23. A method of releasing heat shock proteins in a mammal having a disease of the skin or other barrier tissues of the body, comprising:

exposure of at least a portion of the skin, mucosal layers, blood vessel walls, or other barrier tissues of the mammal to a non-destructive pulsed laser beam,

wherein a pulse frequency of the pulsed laser beam is from about 1 Hz to about 100 kHz, wherein a pulse duration of the pulsed laser beam is from about 0.1 nanoseconds to about 200 nanoseconds,

wherein an irradiance of the pulsed laser beam during the pulse duration is from about 0.1 W/cm² to about 10 W/cm²,

wherein a duration of the exposure is from about 10 s to about 600 s, and

wherein the exposure increases a temperature in tissue adjacent to the exposed portion of the skin, mucosal layers, blood vessel walls, and barrier tissues to a temperature from 39⁰C to about 45⁰C.

24. The method of Claim 23,

wherein the exposure is repeated up to about 10 times.

25. The method of Claim 23,

wherein a diameter of the laser beam is from about 1 mm to about 100 mm.

26. The method of Claim 23,

wherein a wavelength of the laser beam is from about 500 nm to about 3000 nm.

27. The method of Claim 23,

wherein the laser beam is applied to the exposed portion of skin or other barrier tissues directly or through lenses or fiber optic cables, and is applied on the outside of the body or internally using additional devices such as endoscopes and catheters.

28. The method of Claim 23,

wherein a laser producing the laser beam is a diode laser or a fiber laser.

29. The method of Claim 23,

wherein an intensity profile of the laser beam is Gaussian, orthogonal, parabolic, or flat top.

30. The method of Claim 23,

wherein the diseases are associated with abnormal cells having an altered cell constituent consisting of an antigen or non-self particle altered structure, including premalignant cells with precancerous antigenic changes; malignant cells with tumor antigens; virally infected cells expressing viral antigen or containing viral antigens; bacterially infected cells with intracellular bacteria containing bacterial antigens, including mycobacteria infections within cells, including Mycobacterium tuberculosis atypical mycobacteria, and Mycobacterium leprae; fungally infected cells containing fungal antigens; parasitic infected cells containing parasitic antigens, which may or may not be expressed also on the cell surface; and infections by cell-wall deficient bacterial-like organisms including rickettsia, mycoplasma, and anaplasma.

31. The method of Claim 23,

wherein the diseases include actinic keratosis, lichen planus, squamous cell carcinoma, basal cell carcinoma, melanoma, Merkel cell carcinoma, mycosis fungoides, Kaposi's sarcoma, lymphomatoid papulosis, Sezary's syndrome, skin and genital warts, infections by Herpes simplex virus types 1 and 2, infections by Herpes zoster, molluscom contagiosum, peptic or duodenal ulcers due to Helicobacter pylori, skin infections due to MRSA, burkholderia, Haemophilus ducreyi or propionebacterium acnes, donovanosis, sporothrix schenkii, mycetoma, blastomycosis, onychomycosis, tinea pedis, tinea capitis, trichophyton rubrum, or leishmaniasis.

32. The method of Claim 23,

wherein the disease-affected area comprises at least a part of a lesion.

33. The method of Claim 23,

wherein the barrier tissues include lining of the mouth, nose, trachea, bronchi, lung, esophagus, stomach, gut, peritoneum, bladder, urethra, penis, prostate, uterus, vagina, arteries, veins or capillaries.