MXPA00006435A - Coating of polymers - Google Patents

Abstract

Biomedical devices, such as ophthalmic lenses, and methods of making such devices having a surface coating including at least one polyionic layer. A preferred method involves spray coating a polycationic material onto a core lens, rinsing and drying the lens, followed by spray coating a polyanionic material, rinsing and drying. The coating process may be applied a plurality of times to achieve a multi-layer coating on the lens surface. A particularly preferred embodiment is a contact lens comprising a highly oxygen permeable hydrophobic core coated with a 5 to 20 bilayers of hydrophilic polyionic materials.

Description

POLYMER COATING The invention relates to surface treatment technology for biomedical devices, and in particular, to methods for altering the hydrophobic or hydrophilic nature of the polymeric surface of an ophthalmic lens, such as a contact lens. In a preferred embodiment, this invention relates to methods for the treatment of biomedical devices, such as contact lenses, in order to increase the hydrophilicity of the surface. Many devices and materials used in different biomedical applications require certain properties in the volume of the device or material, requiring different and separate properties for the surface. For example, contact lenses preferably have high oxygen permeability through the lens to maintain good corneal health, but materials that normally exhibit exceptionally high oxygen permeability (eg, polysiloxanes) are hydrophobic and adhere to the eye Accordingly, a contact lens can have a core or volume material that is highly permeable to oxygen and hydrophobic, and a surface that has been treated or coated to increase hydrophilicity, thereby allowing the lens to move freely over the eye. In order to modify the hydrophilicity of a relatively hydrophobic contact lens material, a contact lens can be treated with a plasma treatment. A high quality plasma treatment technique is disclosed in International Publication Number WO 96/31792 by Ni-colson et al. However, some plasma treatment processes require a significant investment in equilibrium. Moreover, plasma treatment requires that the lens be dry before being exposed to plasma. Therefore, lenses that are wet from the previous hydration or extraction processes must be dried, imposing drying equipment costs, and adding time to the total lens production process. According to the foregoing, there remains a need for an economic method to consistently and permanently alter the surface properties of polymeric biomaterials, especially ophthalmic lenses, such as contact lenses. A particularly preferred method would be one that could be used directly on wet lenses, ie, without requiring a preliminary drying step. Patents of the United States of North America Numbers ,518,767 and 5,536,573, issued to Rubner et al., Describe methods for producing bilayers of electrically conductive polycationic polymers added p-type, and polyanions or water-soluble nonionic polymers on glass substrates. In these Rubner patents, extensive prior chemical treatments of glass substrates are described. The deposit methods of polyelectro ito layer by cap described in the patent and literature references, refer in general to the production of electronic devices, and to the treatment of rigid glass substrates. Notoriously, the teachings indicate that a complex and delayed pretreatment of the substrate is required to produce a surface having a highly charged hydrophilic or hydrophobic nature, in order to link the polycationic or polyanionic material to the glass substrate. An object of the invention is to provide a method for the treatment of polymers, in particular ophthalmic lenses, in order to alter the surface properties. Another object of the invention is to reduce the complexity of the lens production processes. A further object of the invention is to provide contact lenses having a balance of excellent oxygen permeability through the lens, and sufficient hydrophilicity on the surface, to allow free movement of the lens when placed in the eye of a user. Still another object of the invention is to reduce the material and labor costs of the production of high quality contact lenses. Still a further object of the invention is to provide a method for altering the surface properties of a wet ophthalmic lens, without requiring a previous drying step. The aforementioned objects and other advantages of the invention can be seen from the following summary and detailed description of the invention. One embodiment of the invention is a polymeric device, preferably a biomedical device, comprising a core material and a surface coating. The surface coating includes at least one bilayer of polyelectrolytes. The bilayer includes a first polyionic material that is bonded to the core material, and a second polyionic material, having charges opposite the charges of the first polyionic material, which is bonded to the first polyionic material. Another embodiment of the invention is a method for producing a biomedical device having a core material and a surface coating, including at least one bilayer of polyionic materials, including the steps of contacting a material of core with a first poly-ionic material, thereby bonding the poly-ionic material to the core material to form a biomedical device coated; and contacting the coated device with a second polyionic material having charges opposite to the charges of the first polyionic material, thereby forming a biomedical device having a poly-ionic bilayer.

A group of preferred core materials are those that do not have a substantial surface charge density. The preferred biomedical device is an ophthalmic lens, especially a contact lens. Still another embodiment of the inventions is an attachment for supporting an article, which includes a core material having a dispersed plurality of transient or permanent charges on or near the surface of the material, and a surface coating, which includes a material poly-ionic that binds to the core material. A further embodiment of the invention is a mold for making an article, which includes a core material having a dispersed plurality of transient or permanent charges on or near the surface of the material, and a surface coating, including a poly-ionic material which is bonded to the core material. Yet a further embodiment of the invention is a method for forming an article, and coating the article with a transfer graft of a coating material from the mold in which the article was produced, which comprises the steps of: (a) applying a coating a poly-ionic material to a mold, (b) dosing a liquid molding material into the mold, (c) allowing the mold coating to be transferred from the mold to the molding material, and (d) causing The liquid mold material is hardened (for example, by polymerization), to form a solid molded article having a polyionic coating. Still another embodiment of the invention is a method for altering the surface of an article, which includes the steps of: (a) applying to an article a coating of a poly-ionic material that includes functional groups, and (b) putting on contact the coated article with a material that reacts with the functional groups, to graft the material onto the poly-ionic coating. The embodiments of the present invention include a biomedical device, such as an ophthalmic lens, having a polyelectrolyte surface treatment, and a method of applying the surface treatment to a biomedical device. A particularly preferred embodiment is a contact lens having a hydrophobic core highly permeable to oxygen, and a hydrophilic surface or surfaces. In order to better clarify the technology, certain terms will be defined before describing the details of the invention. The term "biomedical device", as used herein, includes a wide variety of devices used in the biological, medical, or personal care industries. Biomedical devices include, without limitation, ophthalmic lenses, drug delivery devices, such as oral osmotic devices and transdermal devices, catheters, containers for disinfecting and cleaning contact lenses, breast implants, stents, organs and artificial tissues , and similar. "Ophthalmic lenses", as used herein, refers to contact lenses (hard or soft), intraocular lenses, eye patches, and artificial corneas. In a preferred embodiment, an "ophthalmic lens" refers to lenses that are placed in intimate contact with the eye or tear fluid, such as contact lenses for vision correction (e.g. spherical, toric, bifocal), lenses contact for the modification of eye color, ophthalmic drug delivery devices, ocular tissue protective devices (e.g., lenses that promote ophthalmic healing), and the like. A particularly preferred ophthalmic lens is a contact lens for prolonged use, especially contact lenses for prolonged use for vision correction. "Hydrophilic", as used herein, describes a material or a portion thereof that will be associated more readily with water than with lipids. A "hydrophilic surface", as used herein, refers to a surface that is more hydrophilic (ie, more lipophobic) than the material returned or core of an article. Accordingly, an ophthalmic lens having a hydrophilic surface, discloses a lens having a core material having a certain hydrophobicity surrounded, at least in part, by a surface that is more hydrophilic than the core. "Poly-ion" or "poly-ionic material", as used herein, refers to a polymeric material that includes a plurality of charged groups, including polyelectrolytes, added p-type and n-type conductive polymers. Poly-ionic materials include both polycations (which have positive charges) and polyanions (which have negative charges).

. Coating Processes and Materials A. Coating Processes One embodiment of the invention is a method for producing an ophthalmic lens having a core material and a surface coating that includes at least one bilayer of polyionic materials, which includes the steps contacting a core lens with a first poly-ionic material, thereby bonding the poly-ionic material to the core lens to form a coated lens; and contacting the coated lens with a second polyionic material having charges opposite to the charges of the first polyionic material, thereby forming a contact lens having a polyelectrolyte bilayer. The coating application can be performed in a number of ways. One method of coating process exclusively involves the steps of coating by immersion and rinsing by immersion. Another form of coating process involves only the steps of coating by spraying and rinsing by spraying. However, a number of alternatives involve different combinations of spray and immersion coating and rinse steps, which can be designed by a person having ordinary experience in the subject. An immersion coating alternative involves the steps of applying a coating of a first polyionic material to a core lens, by immersing the lens in a first solution of a first polyionic material; in cleaning the lens by immersing the lens in a rinsing solution; and optionally, drying the lens. This procedure is then repeated using a second polyionic material, the second polyionic material having opposite charges to the charges of the first polyionic material, in order to form a poly-ionic bilayer. This bilayer forming process can be repeated a plurality of times in order to produce a thicker coating of the lens. A preferred number of bilayers is about 5 to about 20 bilayers. A preferred number of bilayers is from about 10 to about 15 bilayers. Although more than 20 bilayers are possible, it has been found that delamination can occur in coatings that have an excessive number of bilayers.

The immersion time for each of the coating and rinsing steps may vary depending on a number of factors. Preferably, immersion of the core material in the polyionic solution occurs over a period of about 1 to 30 minutes, more preferably about 2 to 20 minutes, and most preferably about 1 to 5 minutes. The rinsing can be performed in one step, but a plurality of rinsing steps have been found to be very efficient. Rinsing is preferred in a series of about 2 to 5 steps, with each dip in the rinsing solution being preferably from about 1 to about 3 minutes. Another mode of the coating process involves a series of spray coating techniques. The process generally includes the steps of applying a coating of a first polyionic material to a core lens, contacting the lens with a first solution of a first polyionic material; rinse the lens by spraying the lens with a rinse solution; and optionally drying the lens. Similar to the dip coating process, the spray coating process can then be repeated with a second polyionic material, the second polyionic-Q material having opposite charges to the charges of the first polyionic material. Contact of the lens with the solution, either poly-ionic material or rinsing solution, can occur through a variety of methods. For example, the lens can be immersed in both solutions. A preferred alternative is to apply the solutions in a spray or mist form. Of course, different combinations can be envisaged, for example, immersing the lens in the polyionic material, followed by spraying with the rinsing solution. The spray coating application can be carried out by a number of methods known in the art. For example, a conventional spray pattern configuration can be used, that is, the liquid material is sprayed by the application of fluid, which may or may not be at a high pressure, through a small diameter nozzle that is directed towards the deposit objective. Another spray coating technique involves the use of ultrasonic energy, for example, wherein liquid is atomized by the ultrasonic vibrations of a spray-forming tip, and in this way is changed to a spray, as disclosed in the US Pat. United States of America Number 5,582,348. Yet another method is the electrostatic spray coating, wherein a load is transmitted to the fluid or droplets to increase the efficiency of the coating, an example of which is described in U.S. Patent No. 4,993,645. A further method for atomizing liquid for the spray coating involves purely mechanical energy, for example, by contacting the liquid with a high-speed reciprocating member or a high-speed rotating disk, as disclosed in the US Pat. United States of America Number 4,923,123. Yet another method for producing microdroplets for sprayed coatings involves the use of piezoelectric elements to atomize the liquid. Examples of spray coating techniques and devices employing piezoelectric elements are described in U.S. Patent Nos. 5,530,465, 5,630,793 and 5,624, 608. Some of the techniques described above can be used with air or pressure assistance Elevation of the solution. In addition, a combination of two or more techniques with some materials and conditions may be useful. A preferred method of spray application involves dosing the polyanion or polycation solution using a metering pump to an ultrasonic metering head. The poly-ion layer is sprayed to allow surface droplets to coalesce through the surface of the material. The "layer" can then be allowed to interact for a period of time, or be immediately rinsed with water or serum rinse (or another solution that does not have polyanion or polycation). A person having ordinary experience in this field may select one or more coating methods without undue experimentation, given the extensive teachings provided herein. According to the above, the invention is not limited to the particular spray coating technique that is employed.

B. Coating Materials 1. Polymeric Materials A first preferred polyionic material is a polycationic material, ie, a polymer having a plurality of positively charged groups along the polymeric chain. For example, polycationic materials can be selected from the group consisting of: (a) poly (allylamine hydrochloride) (PAH) (b) poly (ethyleneimine) (PEI) CH2- CH; NH "+ - (c) poly (vinylbenzyltriamethylamine) (PVBT) (d) polyaniline (PAN or PAÑI) (added type p) [or sulfonated polyaniline]. (e) polypyrrole (PPY) (added type p) (f) poly (pyridinium-acetylene) A second preferred polyionic material is a polynionic material, ie, a polymer having a plurality of negatively charged groups along the polymer chain. For example, polyanionic materials can be selected from the group consisting of: (a) polymethacrylic acid (PMA) (b) polyacrylic acid (PAA) (c) poly (thiophene-3-acetic acid) (PTAA) (d) poly (4-styrenesulfonic acid) or sodium poly (styrene-sulfonate) (PSS or SPS) The above lists are meant to be exemplary, but clearly not exhaustive. A person having ordinary experience in the field, given the disclosure and teaching of this, could select a number of other useful poly-ionic materials. The molecular weight of the polyionic materials may vary in order to alter the characteristics of the coating, such as the thickness of the coating. As the molecular weight increases, it generally increases in thickness of the coating. However, as the molecular weight increases, the handling difficulty increases. In order to achieve a thickness balance of the coating and handling of the material, the polyionic materials preferably have a number average molecular weight of from about 10,000 to about 150,000. More preferably, the molecular weight MQ is from about 25,000 to about 100,000, and still more preferably from 75,000 to 100,000. 2 . Polyalkylamines A particularly preferred assembly of polyionic materials useful in accordance with the present invention are derivatives of a polyallylamine having a weight average molecular weight of at least 2,000 which, based on the number of amino groups of polyallylamine, comprises approximately 1 to 99 percent of units of the formula: Where R is alkyl of 2 to 6 carbon atoms, which is substituted by two or more same or different substituents selected from the group consisting of hydroxyl, alkoxyloxy of 2 to 5 carbon atoms, and alkylaminocarbonyl- loxyl of 2 to 5 carbon atoms. R is preferably linear alkyl of 3 to 6 carbon atoms, more preferably linear alkyl of 4 to 5 carbon atoms, and most preferably normal pentyl, which in each case is substituted as defined above. Suitable substituents of the alkyl radical R are -OH, a radical -0-C (0) -R? , and / or a radical -O-C (O) -NH-R? ', where Ri and R! are each independently of the other, alkyl of 1 to 4 carbon atoms, preferably methyl, ethyl, or n- or iso-propyl, and more preferably methyl or ethyl. Preferred substituents of the alkyl radical R are hydroxyl acetyloxy, propionyloxy, n- or iso-butanoyloxy, methyla nocarbonyloxy, or ethylaminocarbonyloxy, especially hydroxy, acetyloxy, or propionyloxy, and in particular hydroxyl.

A preferred embodiment of the invention relates to units of the formula (1), wherein R is Cp-linear alkyl which comprises p aforementioned different substituents, and p is 2, 3, 4, 5, 6 6, preferably 4 or 5, and particular 5. R is still more preferably Cp-alkyl which comprises p hydroxyl groups which may be partially or completely acetylated, and p is 4 or 5, in particular 5. Particular preferred R-radicals are 1, 2, 3, 4, 5-pentahydroxy-pentyl or 1, 2, 3, 4, 5-pentahydroxy-n-pentyl, where the hydroxyl groups are partially or completely acetylated. The polymers of the invention are derivatives of a polyallylamine which, based on the number of amino groups of the polyallylamine, comprise from about 1 to 99 percent, preferably from 10 to 80 percent, more preferably from 15 to 75 percent. percent, still more preferably 20 to 70 percent, and in particular 40 to 60 percent of units of the formula (1). The polymers of the invention are conveniently soluble in water. A preferred group of polyallylamine polymers comprise at least 1 percent, more preferably at least 5 percent, and most preferably at least 10 percent units of the formula (la), based on the number of groups amino of polyallylamine. A preferred group of polyallylamine polymers have a weight average molecular weight of, for example, 2,000 to 1,000,000, preferably from 3,000 to 500,000, more preferably from 5,000 to 150,000, and in particular from 7,500 to 100,000. The polyallylamine polymers can be prepared in a manner known per se. For example, a polyallylamine having a weight average molecular weight of at least 2,000, comprising units of the formula (la) above, can be reacted with a lactone of the formula: wherein (alk) is linear or branched alkylene of 2 to 6 carbon atoms, the sum of (tl + t2 + t3) is at least 1, and Rx and R? t are as defined above, to give a polymer of polyallylamine comprising units of formulas (1) and (la). The reaction between the polyallylamine and the lactone can be carried out in a manner known per se; for example, polyallylamine is reacted with the lactone in an aqueous medium at a temperature of about 20 ° C to 100 ° C, and preferably 30 ° C to 60 ° C. The proportion of units of the formula (1) in the final polymer is determined by the stoichiometry of the reactants. The lactones of the formula (6) are known or can be prepared according to known methods. The compounds of the formula (6) wherein t2 or t3 is > 1, are available, for example, by reacting the respective hydroxyl compound of the formula (6) with a compound R? -C (0) X or R '-NCO under conditions well known in the art. Polyallylamine starting materials of different molecular weights are commercially available, for example, in the hydrochloride form. This hydrochloride is previously converted to the free amine, for example, by treatment with a base, for example with a solution of sodium or potassium hydroxide. Polyallylamines comprising additional modifying units can be prepared by adding the reaction mixture of the polyallylamine and the compound of the formula (6) in a simultaneous manner, or preferably in a successive manner with one or more other compounds, for example , from the group of: R2-C (6a) R, - N = C = 0 (6d), ? -CH2- O- (60, -R4 15 (6g), R - C - I Re-X (6h), O (60, -R.

O wherein X is halogen, preferably chlorine, (alk1) and alkylene of 1 to 12 carbon atoms, R12 is hydrogen or to the chyle of 1 to 2 carbon atoms, preferably methyl hydrogen, and R3, R4, R5, R5 ', R6, and Qt are as defined above. The reaction proceeds, for example, in an aqueous solution at room temperature or at an elevated temperature of, for example, 25 ° C to 60 ° C, and produces polymers comprising units of the formula (2a) [with compounds of the formulas (6a ), (6b), or (6c)], units of the formula (2b) [with compounds d of the formulas (6d), (6e)] units of the formula (2c) [with compounds of the formula (6f)] , units of the formula (2d) [co compounds of the formula (6g)], or units of the formula (2e) [with compounds of the formulas (6h), (6i), (6j), (6k)].

Because the reaction of the amino groups of the poly-liamine with the compounds of the formulas (6) or (6a) - (6) proceeds generally in a quantitative manner, the structure of the modified polymers is determined primarily by the stoichiometry of the reagents that are used in the reaction.

A particularly preferred polyionic material is polyallylamine glu conolactone, as shown in formula 7. Particularly preferred is a polyallylamine wherein about 20 to 80 percent of the amino groups have been reacted with delta-glucolactone to produce R groups of the formula shown in formula 7.

In a preferred embodiment, the surface treatment methods of the present invention involve the steps of: (a) applying a coating of a cationic PEI, (b) applying a coating of an anionic PAA, and (c) applying a cationic layer of polyallylamine gluconolactone. In another preferred embodiment, steps (b) and (c) are repeated a plurality of times, preferably from about 2 to 7 times, more preferably from about 3 to 5 times.

C. Coating Functions, Characteristics, and Theory Separating the charged nature of the poly-ionic material, a wide variety of poly-ionic materials can be useful in the production of a wide variety of product properties. For example, for long-term contact lenses, the particularly preferred polyionic materials are hydrophilic, or those that generate a hydrophilic surface coating, in order to inhibit the adhesion of the lens to the surface of the user's eyes. Another class of polyionic materials useful for general and biomedical applications, and ophthalmic lenses in particular, are those which exhibit antimicrobial properties. Antimicrobial polyionic materials include ternary polyuane ammonium compounds, such as those described in US Pat. No. 3,931,319, issued to Green et al. (Eg, POLYQUAD®). Yet another class of polyionic materials useful for ophthalmic lenses are those that have radiation absorbing properties, such as visibility dyeing agents, modified iris color dyes, and dyeing dyes for ultraviolet light (UV). Yet a further example of useful coating materials are those polyionic materials that inhibit or induce cell growth. Cell growth inhibitors would be useful in devices that are exposed to human tissue for a prolonged time with the final intention to be removed (eg, catheters), while poly-ionic cell-growth-inducing materials would be useful in cell-based devices. permanent implants (for example, artificial corneas). Still another potential functional class of coating materials are those that absorb radiation, for example ultraviolet (UV) light blockers. There are a number of other biomedical applications of the present coating processes, and a person having ordinary experience in this field could conceive them without departing from the spirit and scope of the present invention. The processes of the present invention allow the production of an ophthalmic lens having a core material and a surface coating. The surface coating includes at least one layer of polyelectrolytes, and in a preferred embodiment, at least one bilayer. A bilayer includes a first polyionic material that is bonded to the core material, and a second polyionic material, having opposite charges to the charges of the first polyionic material, which is bonded to the first polyionic material. In an unexpected manner, it has been found that polymeric materials that do not have theoretical ionic charges on their surfaces, or do not have a substantial amount of actual charges, can be coated according to the present process. The teachings of the electronic industry of dip coating methods of electronic components in solutions of polyionic materials indicate that highly charged surfaces (eg, glass) are required for proper adhesion of the charged polymeric materials. However, it has been found that multiple wear-resistant coating layers can be deposited on the surfaces of contact lenses that are not highly charged, and even on surfaces that do not have a substantial theoretical charge density. It was very unexpected to find that no preliminary treatments were required, for example, plasma (to generate charges on the surface of the lens, in order to ensure that the charged polymers would adhere to the surface of the lens) Therefore one embodiment of the present invention is refers to the coating of core lens materials having a surface charge density in the range of contact lenses (especially siloxane-containing lenses) in the absence of preceding surface treatments. Therefore, one embodiment of the present invention relates to to the coating of core lens materials having a surface charge density that is essentially unaltered, i.e., less than a surface charge density of a material that has been pretreated to increase the charge density. is not limited to the theory developed to support this inesper result adored, a theory proposed in the present is presented in order to make it possible for the reader to understand the invention better. The electronic component treatment technique teaches that extensive surface preparation processes are required to produce a highly charged surface in a positive or negative manner that attracts the oppositely charged groups of a polyionic coating material. However, it has unexpectedly been found that these extensive pre-processing processes are unnecessary for ophthalmic lenses, and in fact, that uncharged or substantially uncharged surfaces can be coated by contacting the uncharged surface with a polygenic species. highly charged ionic In view of this unexpected discovery, it is believed that a very small number of charges can exist in a transient or permanent dispersed state in any material, such as a core lens material, and it is this small number of charges that allows the Highly charged polyionic material is bonded to the core lens material. One proposed explanation is that the core lens material has a low density of transient negative charges on its surface, while the polycationic material (bonded on that surface) has a high density of permanent positive ions along the base structure. -limeric Although there are very few negative charges, and the charges are of a transient nature (ie, a particular location is only charged for a small fraction of time), nevertheless, it is believed that substantially all negative charges are associated with a positive charge. -tiva on the polycationic material.

In addition, it is believed that the total number of transient or permanent negative charges on the lens surface, n changes substantially with time, i.e., the density d negative charge on the surface is essentially constant, but the position or location may be transient. . Consequently, although the negative charges may be transient, that is, the charges appear and disappear across the surface as time passes, the total number of charges is essentially constant. In view of the unexpected experimental results, it is theorized that, if the location of the negative charges on the surface is transient, the transient nature is not a problem for the polycationic bond strength (ie, the durability of the coating), due to that, as a negative charge disappears, and an ionic bond is lost, another negative charge appears elsewhere, and another ionic bond forms with the polycationic material. Alternatively, the charges on the surface of the lens polymer may be permanent but highly dispersed. Again, although the charge density is theoretically very low, whether of a permanent or transient nature, it has unexpectedly been found that this very low charge density is still sufficient to allow the polyelectrolyte material to bond to the lens surface with enough strength for ophthalmic applications. That is, the subsequent cleaning and disinfecting of the lens, as well as the USQ handling of the lens, with the associated and inevitable surface abrasion, do not substantially damage the polyelectrolyte coatings of the present invention. However, in order to compensate for the low charge density of the core lens polymer, the charge density of the polyionic coating material is preferably relatively high. The charge density of the polyionic material can be determined by any of a number of means known in the art. For example, charge density can be determined by Streming Zeta Potential.

D. Characteristics and Application of the Solution The concentration of the spray or immersion solution may vary depending on the particular polyionic materials involved, the desired thickness of the coating, and a number of other factors. However, it is generally preferred to formulate a relatively dilute aqueous solution of polyionic material. A preferred concentration of polyionic material is from about 0.001 to about 0.25 percent by weight, more preferably from about 0.005 to about 0.10 percent, and more preferably from about 0.01 to about 0.05 percent .

In order to keep the polyionic material in a highly charged state, the pH of the diluted polyionic solution should be maintained at from about 2 to about 5, more preferably from about 2.5 to about 4.5. The rinse solution is preferably an aqueous solution regulated at a pH of from about 2 to about 7, more preferably from about 2 to about 5, and even more preferably from about 2.5 to about 4.5, in order to improve the binding of the poly-ionic material to the core or to the underlying poly-ionic material. Partial drying or removal of excess surface rinsing solution between applications in solution may be performed by a number of means known in the art. Although the lens can be partially dried merely by allowing the lens to remain in an air atmosphere for a certain period of time, it is preferable to accelerate the drying by applying a slight draft to the surface. The flow rate can be adjusted as a function of the strength of the material being dried, and the mechanical fixation of the material (ie, excessive flow velocities can damage the lens or dislodge the lens from the retention element). It should be noted that there is no requirement to completely dry the lens. The "partial drying" step, as used herein, refers to a removal of solution droplets that run off to the lens surface, rather than a drying out of the lens. Accordingly, it is preferred to dry: only to the extent that any film of water or solution on the surface is removed. The thickness of the coating can be adjusted by the addition of one or more salts, such as sodium chloride, to the polyionic solution. A preferred salt concentration is from about 0.1 to about 2.0 weight percent. As the salt concentration increases, the polyelectrolyte takes on a more globular shape. However, if the concentration rises too high, the polyelectrolyte will not deposit well, if any, on the surface of the lens. A more preferred salt concentration is from about 0.7 to about 1.3 weight percent. The thickness of the coatings can be determined by the addition of a dye to the polyionic solution, for example, methylene blue dye. Increases in visible light absortion correlate with increases in coating thickness. In addition, ellipsometry measurements can be used to measure the thickness of the coating. For the modification of the hydrophilic surface, the measurement of the contact angle of the water applied to the surface gives a relative indication of the surface hydrophilicity. As the contact angle decreases, hydrophilicity increases.

II. Adequate Ophthalmic Lens Core Materials. The polymeric material forming the contact lenses used in accordance with the present invention may be any of a wide variety of polymeric materials. However, a preferred group of materials are those materials that are highly permeable to oxygen, such as polymers containing fluorine or siloxane. In particular, the polymeric materials described in U.S. Patent No. 5,760,100, issued to Nicolson et al., On June 2, 1998, are an example group, and the teachings of this patent are incorporated herein by reference. reference. For the convenience of the reader, examples of suitable materials are disclosed herein, without limitation thereto.

A. Material "A" A suitable core material embodiment of the present ophthalmic lens is a polymer formed from the following monomeric and macromer components: (a) from about 5 to about 94 percent by dry weight of a macromer that has the segment of the formula: CP-PAO-DU-ALK-PDMS-ALK-DU-PAO-CP wherein: PDMS is a divalent poly (disubstituted siloxane), ALK is an alkylene or alkyleneoxy group having at least 3 carbon atoms, DU is a group containing diurethane, PAO is a divalent polyoxyalkylene, and CP is selected from acrylates and methacrylates, wherein the macromer has an average molecular weight and number from 2,000 to 10,000; (b) from about 5 to about 60 weight percent methacryloxypropyltris (trimethylsiloxy) silane; (c) from about 1 to about 30 weight percent of an acrylate or methacrylate monomer; and (d) from 0 to 5 weight percent of a crosslinking agent, the percentages by weight based on the dry weight of the polymer components being based. A preferred polysiloxane macromer segment is de-fine by the formula: CP-PAO-DU-ALK-PDMS-ALK-DU-PAO-CP wherein: PDMS is a divalent poly (disubstituted siloxane); CP is an isocyanatoalkyl acrylate or methacrylate, preferably isocyanatoethyl methacrylate, wherein the urethane group is linked to the terminal carbon of the PAO group; PAO is a divalent polyoxyalkylene (which may be substituted), and is preferably a polyethylene oxide, ie (-CH2-CH2-0-) mCH2CH2- wherein m may be from about 3 to about 44, more preferably from about 4 to about 24; DU is a diurethane, preferably including a cyclic structure, wherein an oxygen of the urethane linkage (1) is linked to the PAO group, and an oxygen of the urethane linkage (2) is bonded to the ALK group; and ALK is an alkylene or alkyleneoxy group having at least 3 carbon atoms, preferably a branched alkylene group, or an alkyleneoxy group having 3 to 6 carbon atoms, and more preferably a secondary butyl group (i.e. -CH2CH2CH (CH3) -), or an ethoxypropoxyl group (for example -O- (CH2) 2-0- (CH2) 3-).

B. Material "B": Perfluoroalkylethers comprising po-lysiloxane The macromer of Material "B" is defined by formula (I): Px- (Y) m- (LX pQ-OL) P- (Y), ^ ( I) where: each Pl, independently of the others, is a group free radical polymerizable; each Y, independently of the others, is -CONHCOO-CONHCONH-, OCONHCO-, -NHCONHCO- -NHCO-, -CONH-, -NHCONH-, -COO -OCO-, -NHCOO- or -OCONH-; m and p, independently of one another, are 0 or 1; each L, independently of the others, is a di valent radical of an organic compound having up to 20 carbon atoms; each Xlf independently of the others is -NHCO-, -CONH -NHCONH-, -COO-, -OCO-, -NHCOO- or -OCONH-; and Q is a divalent polymer fragment consisting of the segments: (a) - (E) k -Z-CF2- (OCF2) x- (OCF2CF2) and-OCF2-Z- (E) k-, wherein: x + y is a number on the scale of 10 to 30; each Z, independently of the others, is a divalent radical having up to 12 carbon atoms, or Z is a bond; each E, independently of the others is - (OC ^ CH ^) q-, e where q has a value from 0 to 2, and where the -ZE- link represents the sequence -Z- (0CH2-CH2) q-; and k is 0 or 1; where: n is an integer from 5 to 100; Alk is alkylene having up to 20 carbon atoms; from 80 to 100 percent of the radicals Rx, R2, R3 and R4, independently of one another, are alkyl, and from 0 to 20 percent of the radicals Rx, R2, R3, and R4, independently of one another, are alkenyl, aryl, or cyanoalkyl; and (CJ 2-K.-, where: R is a divalent organic radical having up to 2 carbon atoms, and each X2, independently of the others, is -NHCO-, -CONH-, -NHCONH-, -COO -, -OCO-, -NHCOO- or OCONH-, with the proviso that there must be at least one of each segment (a), (b), and (c) in Q, that each segment (a) or (b) ) has a segment (c) attached to it, and each segment (c) has a segment (a) or (b) attached to it.The number of segments (b) in the polymer fragment is preferably greater than, or equal to, the number of segments (a) The ratio between the number of segments (a) and (b) to the polymer fragment Q is preferably 3: 4, 2: 3, 1: 2, or 1 : 1. The molar ratio between the number of segments (a) (b) in the polymer fragment Q is more preferably d 2: 3, 1: 2, or 1: 1. The average molecular weight of the polymer fragment Q is on the scale of approximately 1,000 to approximately 20,000, preferably on the approximate scale about 3,000 about 15,000, in a particularly preferred manner on the scale of about 5,000 to about 12,000. The total number of segments (a) and (b) in the polymer fragment Q is preferably on the scale of 2 to about 11, particularly preferably in the range from 2 to about 9, and in particular in the scale of 2 about 7. The smallest polymer unit Q is preferably composed of a segment of perfluor (a), a segment of siloxane (b), and a segment (c).

C. Material "C" Polymers of material "C" are formed by the polymerization of polymerizable macromers containing free hydroxyl groups. Macromers are disclosed which are constructed, for example, from an amino-alkylated polysiloxane, which is derived with at least one polyol component containing an unsaturated polymerizable side chain. Polymers can be prepared, on the one hand, from the macromers according to the invention, by homopolymerization. The aforementioned macromers can be mixed and polymerized with one or more hydrophilic and / or hydrophobic comonomers. A special property of the macromers according to the invention is that they function as the element that controls the microphase separation between the selected hydrophilic and hydrophobic components in a crosslinked final product. The separation of hydrophilic / hydrophobic microphases is in the region of less than 300 nanometers. The macromers are preferably crosslinked at the phase boundaries between, for example, an acrylate comonomer on the one hand, and an unsaturated polymerizable side chain of polyols linked to the polysiloxane on the other hand, by covalent bonds, and additionally by reversible physical interactions , for example hydrogen bridges. These are formed, for example, by numerous amide or urethane groups. The continuous siloxane phase that exists in the phase compound has the effect of producing a surprisingly high permeability to oxygen. The polymers of the material "C" are formed by the polymerization of a macromer comprising at least one segment of the formula (I): -a-Z- -b- i (I) d wherein: (a) is a polysiloxane segment, (b) is a polyol segment containing at least 4 carbon atoms, Z is a segment (c) or a group Xlf (c) is defined as X2-R- X2, wherein: R is a divalent radical of an organic compound having up to 20 carbon atoms, and each X2, independently of the other, is a divalenal radical containing at least one carbonyl group, Xx is defined as X2, and (d) is a radical of the formula (II): X3-L- (Y) k-Px (II) wherein: Px is a group that can be polymerized by free radicals; Y and X3, independently of one another, are a divalent radical containing at least one carbonyl group; k is 0 or 1; and L is a bond or a divalent radical having up to 20 carbon atoms of an organic compound. A polysiloxane segment (a) is derived from a compound of the formula (III): where: n is an integer from 5 to 500; from 99.8 to 25 percent of the radicals R17 R2, R3, R4, R5, and R6, independently of one another, are alkyl, and from 0.2 to 75 percent of the radicals R, R2, R3, R4, Rs, and R6, independently of each other, are partially fluorinated alkyl, aminoalkyl, alkenyl, aryl, cyanoalkyl, alk-NH-alk-NH2 or alk- (OCH2) m- (OCH2) p-OR7, R7 is hydrogen or lower alkyl, alk is alkylene, and m and p, independently of each other, are an integer from 0 to 10, one molecule containing at least one primary amino or hydroxyl group. Alkylene oxyl groups. { OCH2-CH2) my- (OCH2) p in the si-loxane of the formula (III), are randomly distributed in an alk- (OCHjC j) m- (OCH2) p-0R7 ligand, or are distributed as blocks in a chain. A segment of polysiloxane (a) is bonded a total of 1 to 50 times, preferably 2 to 30 times, and in particular 4 to 10 times, by means of a group Z, with a segment (b) or another segment (a), Z always being in a sequence aZa, a segment (c). The binding site in a segment (a) with a group Z in an amino or hydroxyl group is reduced by a hydrogen.

D. "Material D" Another useful core material involves the polymerization of a siloxane-containing macromer that is formed from a poly (dialkylsiloxane) dialkoxyalkanol, which has the following structure: HO-R.-O-R- R3-0-R4-OH 1 2 n wherein: n is an integer from about 5 to about 500, preferably from about 20 to 200, more preferably from about 20 to 100; the radicals Rlf R2, R3, and R4, independently of one another, are lower alkylene, preferably alkylene of 1 to 6 carbon atoms, more preferably alkylene of 1 to 3 carbon atoms, wherein, in a preferred embodiment, the total number of carbon atoms in R1 and R2, or in R3 and R4, is greater than 4; and R5, R6, R7, and R8, independently of one another, are lower alkyl, preferably alkyl of 1 to 6 carbon atoms, more preferably alkyl of 1 to 3 carbon atoms.

The general structure of the material D macromer is as follows: ACRYLATE-LINK-ALK-O-ALK-PDAS-ALK-O-ALK-LINK-ACRYLATE wherein the ACRYLATE is selected from acrylates and methacrylates; LINK is selected from urethane and diurethane bonds, ALK-O-ALK is as defined above (R-L-O-R;, - or R30-R4), and PDAS is a poly (dialkylsiloxane). For example, a macromer of Material D can be prepared by the reaction of isophorone diisocyanate, 2-hydroxyethyl (meth) acrylate, and a poly (dialkylsiloxane) -dialkoxyalkanol in the presence of a catalyst.

III. Biomedical Products In addition to the coated ophthalmic lenses described hereinbefore, the present invention can be applied in alternative ways in a biomedical manufacturing environment (eg, ophthalmic lenses). For example, one or more poly-ionic materials may be added to the ophthalmically compatible solution in which a contact lens is stored after it is manufactured. Subsequent to the molding of a contact lens, the lens can be subjected to various post-molding treatments, including, for example, additional curing steps, extraction, inspection, and binding. Finally the lens will be placed in a container or package with a sterile, ophthalmically compatible solution, for storage. In accordance with the present invention, a polymeric ionic material can be added to the storage solution., either before or after sterilization. In a preferred embodiment, a storage solution including a poly-ionic material is added to a lens container, together with a contact lens, the container is sealed, and the container is subjected to a sterilization process (e.g. step by autoclave). Accordingly, one embodiment of the invention is an ophthalmic product that includes retaining by packing a contact lens and an ophthalmically compatible sterile solution, which includes a polyionic material, a tonicity adjusting agent (e.g., sodium chloride). to produce a substantially isotonic solution), and water. Another example utility of the present invention is to provide a means for joining materials to the surface of a biomedical device. More specifically, the methods of the present invention can be used to form a polyionic coating on a biomedical device, and then another material can be attached to the polyionic coating by a number of means, such as chemical reaction by half of functional groups. For example, a coating of poly (ethylenimine) [PEI] may be deposited on the surface of a contact lens by the methods described herein. Using amine functional groups, another material (for example, hyaluronic acid) can be chemically bonded, having chemical groups that react with the amine groups and can be chemically bonded to the PEI coating. Accordingly, still another embodiment of the invention is a method for altering the surface of a material, by applying a polyionic coating having functional groups to the surface, and subsequently contacting the polyionic coating with a second coating material having groups that react with the functional groups, thereby reacting the groups chemically, and bonding the second coating material to the polyionic coating. Clearly, a number of surface treatment regimes can be envisaged given the teachings of this dual treatment method, and these regimes are within the scope of the invention. Still a further embodiment of the invention relates to the insertion of infraocular lenses in the eye. Infraocular lenses (IOLs), as used herein, include lenses that are designed to replace the crystalline lens in the eye capsule bag (eg, used in cataract surgery), and refractive lenses designed for correction of vision, and placed in the posterior or anterior chamber of the eye. The poly-ionic materials and methods disclosed herein, can be used to coat insert guides, plungers, triggers, and infra-ocular lens assemblies, to reduce friction or increase lubricity. The greater lubricity can reduce the difficulty experienced by the ophthalmologist when trying to insert the intraocular lens in the eye.

IV. Manufacturing Processes The present invention can also be used more generally in the manufacture of biomedical articles, such as ophthalmic lenses, wound patches, transdermal drug delivery devices, and similar polymer-based materials. For example, the present invention can be used to surface treat an accessory that supports an article during a manufacturing process. The surface treatment can be useful to increase the lubricity of the surfaces of the fitting that make contact with the article, thereby reducing adhesion, or promoting separation of the accessory article. In an alternative way, the surface treatment can increase the adhesion of, or attraction of, the surface of the accessory to the article, thereby helping to retain the article on the accessory during a transport step or advance in the manufacturing process. A number of other surface treatment functions can be envisaged, such as antimicrobial and anticontaminating activity.

Accordingly, another embodiment of the invention is an accessory for supporting an article that is coated with a polyionic material. The surface of the fixture must be formed of a material having a plurality of transient or permanent loads at or near the surface of the material. The poly-ionic material can be fixed to the surface by contacting it by any number of methods described hereinabove. Another example use of the present invention in a manufacturing establishment involves coating a mold used to define the shape of an article. The mold can be coated for a number of purposes, including, importantly, quick release of the molded article after the article is formed. The mold can be coated by any of the aforementioned methods. Accordingly, another embodiment of the invention is a mold for manufacturing an article, including a material having a plurality of transient or permanent charges on or near the surface of the material, and a surface coating, which includes a polyionic material that it is linked to the core material. Yet another method for using the present technology in a manufacturing establishment can be referred to as the transfer graft of a polyionic coating. In this embodiment, the mold is coated with a polyionic material as described above, but at least one portion of the coating is transferred from the mold when the liquid molding material is dosed (eg, the polymerizable material). in the mold for the formation of the solid article. Accordingly, another embodiment of the invention is a method for forming an article, and coating the article with a transfer graft of a coating material from the mold where the article was produced. This method includes the steps of applying a coating of a poly-ionic material to a mold, contacting at least a portion of the mold with a solution of the poly-ionic material, dosing or liquid molding material in the mold, putting in contact with the mold. This way the liquid molding material with the coating, allow the coating of the mold to contact the liquid molding material for a sufficient time so that at least a portion of the coating is transferred from the mold to the molding material, and causing the liquid mold material to harden (for example, by polymerization by means of the application of ultraviolet light). The above disclosure will make it possible for a person having ordinary experience in the art to practice the invention. In order to make it as easy as possible for the reader to understand the specific modalities and their advantages, a reference to the following examples is suggested.

Example 1 Contact lenses containing siloxane were prepared in substantial accordance with the teachings with respect to "Material B" disclosed in International Publication Number WO 96/31792 by Nicolson et al. On pages 30-41, with a prepolymerization mixture having the percentages by weight of 50 percent of macromer, 20 percent of TRIS, 29.5 percent of DMA, and 0.5 percent of Darocur 1173. Contact lenses were extracted and autoclaved . The average contact angle (n = 20) (Sessle Drop), measured by a VCA 2500 XE contact angle measuring device (AST, Inc. Boston, MA), was approximately 111. The results are reported in the Table TO.

Example 2 A lens prepared according to Example 1 was surface treated with a layer-by-layer (LBL) process, to increase the hydrophilicity of the lens as follows. A dilute (10 ~ 2 molar) aqueous supply solution of poly (allylamine hydrochloride) (50-60,000 MWn from Aldrich Chemicals) [PAH] was prepared by adding 1.3 grams of PAH to 1400 milliliters of deionized water. The pH was adjusted to approximately 2.5 by the dropwise addition of hydrochloric acid. A dilute (10 ~ 2 molar) aqueous supply solution of poly (acrylic acid) (50-60,000 MWn of PolyScience) [PAA] was prepared by adding 4.03 grams of PAA to 1400 milliliters of deionized water. The pH was adjusted to about 4.5 by the dropwise addition of hydrochloric acid. The concentrations of the solution were selected in an attempt to maintain the concentration of the positively charged units as well as the concentration of the negatively charged units. The contact lens was immersed in the PAH application solution for a period of about 15 minutes. After removing the PAH solution, the lens was immersed in three baths of deionized water adjusted to a pH of 2.5 (the same pH as that of the PAH application solution) for periods of two minutes. The rinsing solution adhering to the lens was dislodged by applying a slight stream of air (referred to as "drying" herein). Next, the lens was immersed in the PAA solution for a period of about 15 minutes, rinsed, and dried as described above. The rinse coating steps were repeated four additional times, but the drying steps were eliminated during these coating steps. The average contact angle (n = 4) was 78. The results are reported in Tables A and B.

Example 3 The coated lenses as they were treated in the Example 2, were treated by the dropwise addition of 2 milliliters of a solution of CaCl2 (9 percent by volume), a strongly ionic solution, in order to determine the durability of the coating. The lenses were dried with light air. The average contact angle (n = 6) was 72. The results are reported in Table B.

Example 4 A lens prepared according to Example 1 is surface treated with a layer-by-layer (LBL) process to increase the hydrophilicity according to the procedures illustrated in Example 2, with the following exception: the pH of the solution of application and rinse for the PAA solution was 2.5, as opposed to 4.5 in Example 2. The average contact angle (n = 4) was 65. The results are reported in Tables A and B.

Example 5 The coated lenses as treated in Example 4 were treated by the dropwise addition of 2 milliliters of a CaCl 2 solution. The lenses were dried with light air. The average contact angle (n = 4) was 76. The results are reported in Table B.

Example 6 A lens prepared according to Example 1 is surface treated with a layer-by-layer (LBL) process to increase hydrophilicity. A diluted aqueous supply solution (10 ~ 2 molar) of poly (ethyleneimine) (50-60, 000 MWn of PolyScience) [PEI], was prepared by the addition of 2.00 grams of PAH to 1400 milliliters of deionized water. The pH was adjusted to approximately 2.5 by the dropwise addition of hydrochloric acid. A diluted PAA solution was prepared as in Example 2. The pH was adjusted to approximately 2.5 by the dropwise addition of hydrochloric acid. The contact lens was immersed in the PEI application solution, rinsed, and dried as described in Example 2, followed by a similar treatment with the PAA solution. The coating and rinsing steps were repeated four additional times, but the drying steps were eliminated during these coating steps. The average contact angle (n = 6) was 57. The results are reported in Tables A and B.

Example 7 The coated lenses as treated in Example 6 were treated by the dropwise addition of 2 milliliters of a CaCl 2 solution. The lenses were dried with light air.

The average contact angle (n = 4) was 77. The results are reported in Table B.

Example 8 A lens prepared according to Example 1 is surface treated with a layer-by-layer (LBL) process to increase the hydrophilicity according to the procedures illustrated in Example 6, with the following exception: the pH of the Application and rinse solution for the solution of P7? A was 4.5, as opposed to 2.5 in Example 6. The average contact angle (n = 4) was 72. The results are reported in Tables A and B.

Example 9 The coated lenses as treated in Example 8 were treated by the dropwise addition of 2 milliliters of a CaCl 2 solution. The lenses were dried with light air. The average contact angle (n = 4) was 112. The results are reported in Table B.

DISCUSSION OF RESULTS (EXAMPLES 1-9) A comparison of the contact angles of the lenses treated in Examples 2, 4, 6, and 8 with the contact angle of the untreated lenses of Example 1, illustrates that it has been -sitting a surface modification, or that a coating has been deposited (see Table A). In addition, all treated lenses had significantly reduced contact angles, demonstrating that the hydrophilicity of the surface had increased significantly. In addition, a comparison of the contact angles of the coated lenses of Examples 2, 4, 6, and 8 with the similarly treated lenses of Examples 3, 5, 7, and 9 that have been exposed to a strong ionic solution demonstrate with the exception of Examples 8 and 9, which have not substantially changed the contact angles. Accordingly, the surface modification of the coating unexpectedly is very durable in the presence of a highly charged solution that would be expected to dislodge the charging attractions between the polyionic coating materials and the contact lens surface.

Example 10 A lens prepared according to Example 1 was surface treated with a layer by layer process to functionalize the surface of the lens as follows. Subsequently, active species were attached to the lens by means of the functional groups provided by the coating layer by layer. The lens was treated substantially according to the methods described in the previous Examples. The coating solutions included a first immersion in PEI at a pH of 3.5, a second immersion in PAA at a pH of 2.5, and a final immersion in PEI, again at a pH of 3.5. Subsequently to the coating layer by layer, the lenses were immersed in a solution of hyaluronic acid. It is believed that the hyaluronic acid reacted with the free amine groups on the PEI coating, thereby bonding the hyaluronic acid to the surface of the contact lens.

Example 11 A lens prepared according to Example 1 was surface treated with a layer by layer process to functionalize the surface of the lens as follows. Subsequently, active species were attached to the lens by means of the functional groups provided by the coating layer by layer. The lens was treated substantially according to the methods described in the previous Examples. The coating solutions included a first immersion in PEI (pH of 3.5), a second immersion in PAA (pH of 2.5), a third immersion in PEI, a fourth immersion in PAA, and a final immersion in PEÍ. In this way a 2.5-layer structure was formed. Subsequently to the coating layer by layer, the lenses were immersed in a solution of hiarluronic acid. It is believed that hyaluronic acid reacted with the free amine groups on the final PEI layer, thus linking the hyaluronic acid to the surface of the contact lens. The invention has been described in detail, with reference to certain preferred embodiments, in order to enable the reader to practice the invention without undue experimentation. However, a person having ordinary experience in the art will readily recognize that many of the components and parameters may be varied or modified to some degree, without departing from the scope and spirit of the invention. In addition, headings, headings, definitions, or the like, are provided to improve the understanding by the electorate of this document, and should not be read to limit the scope of the present invention. In accordance with the foregoing, the intellectual property rights to this invention are defined only by the following claims and their extensions and reasonable equivalents.

Claims (38)

1. A biomedical device, which comprises: (a) a core material having a dispersed plurality of transient or permanent charges on or near the surface of the material, wherein the core material has a relatively low surface charge density, - and (b) a surface coating, which includes a polyionic material that is bonded to the core material.

A biomedical device of claim 1, wherein the surface coating includes at least one bilayer, said bilayer comprising: (a) a first polyionic material that is bonded to the core material; and (b) a second polyionic material, having carbon opposed to the charges of the first polyionic material, which is bonded to the first polyionic material.

3. A biomedical device of claim 1, wherein said device is an ophthalmic lens.

4. An ophthalmic lens of claim 3, wherein the surface coating includes a plurality of bilayers.

5. An ophthalmic lens of claim 4, wherein the surface coating includes from about 5 to 20 bilayers.

6. An ophthalmic lens of claim 5, wherein the surface coating includes from about 10 to 15 bilayers.

An ophthalmic lens of claim 3, wherein the first polyionic material is a polycationic material, and the second polyionic material is a polyanionic material.

8. An ophthalmic lens of claim 7, wherein the polycationic material is selected from the group consisting of poly (allylamine hydrochloride), poly (ethylene imine), poly (vinylbenzyltriamethylamine), polyaniline, polypyrrole, po-li (pyridinium-acetylene) ), derivatives thereof, and mixtures thereof.

An ophthalmic lens of claim 7, wherein the polyanionic material is selected from the group consisting of polymethacrylic acid, polyacrylic acid, po-li (thiophene-3-acetic acid), poly (4-styrenesulfonic acid), derivatives thereof and mixtures thereof.

10. An ophthalmic lens of claim 3, wherein the surface charge density of the lens material of the core has not been modified by a prior surface treatment prior to application of the surface coating.

11. An ophthalmic lens of claim 3, which is a contact lens.

12. An ophthalmic lens of claim 3, wherein the core is hydrophobic, and the surface coating is hydrophilic.

13. An ophthalmic lens of claim 8, wherein the hydrophobic core is a siloxane-containing polymer.

14. An ophthalmic lens of claim 3, which is a contact lens, wherein the surface coating includes a plurality of bilayers; wherein the first polyionic material is a polycationic material, the second polyionic material is a polyanionic material; wherein the polycationic material is selected from the group consisting of poly (allylamine hydrochloride), poly (ethylene imine), poly (vinylbenzyltrimethylamine), polyaniline, polypyrrole, poly (pyridinium-acetylene), derivatives thereof, and mixtures of the same; wherein the polyanionic material is selected from the group consisting of polymethacrylic acid, polyacrylic acid, poly (thiophene-3-acetic acid), poly-4-styrene-sulfonic acid), derivatives thereof, and mixtures thereof; and wherein the core is hydrophobic, and the surface coating is hydrophilic.

15. An ophthalmic lens of claim 3, wherein the number average molecular weight of the polyionic material is between 25,000 and 150,000.

16. An ophthalmic lens of claim 15, wherein the number average molecular weight of the polyionic material is between 75,000 and 100,000.

17. A method for producing a biomedical device having a core material and a surface coating that comprises at least one bilayer of polyionic materials, which comprises the steps of: (a) contacting a core material with a first poly-ionic material, thereby bonding the poly-ionic material with the core material to form a coated device; and (b) contacting the coated device with a second polyionic material having opposite charges to the charges of the first polyionic material, thereby forming a device having a polyelectrolyte bilayer.

18. A method of claim 17, wherein the medical device is an ophthalmic lens.

19. A method of claim 18, which comprises the steps of: (a) applying a coating of a first polyionic material to a core lens, immersing this lens in a first solution of a first polyionic material; (b) rinsing the lens by contacting this lens with a rinsing solution; (c) applying a coating of a second polyionic material to the lens, immersing this lens in a second solution of a second polyionic material, wherein the second polyionic material has opposite charges to the charges of the first material poly-ionic; and (d) rinsing the lens by contacting this lens with a rinsing solution.

20. A method of claim 19, wherein at least one of the contacts is presented by immersing the lens in a solution.

21. A method of claim 19, wherein at least one of the contacts is presented by spraying solution onto the lens.

22. A method of claim 19, wherein the pH of the solution is polyionic are between 2 and 5.

23. A method of claim 19, wherein the rinse solutions each have a pH that is within a pH unit from the pH of the previously applied polyionic solution.

24. A method of claim 18, which comprises the steps of: (a) applying a coating of a first polyionic material to a core lens, by contacting this lens with a first solution of a first polymeric material. ionic; (b) rinsing the lens by contacting the lens with a rinsing solution; (c) drying the lens; (d) applying a coating of a second polyionic material to the lens, contacting the lens with a second solution of a second polyionic material, wherein the second polyionic material has opposite charges to the charges of the first material polyionic (e) rinsing the lens by contacting the lens with a rinsing solution; and (f) drying the lens.

25. A method of claim 24, wherein at least one of the contacts is presented by immersing the lens in a solution.

26. A method of claim 24, wherein at least one of the contacts is presented by spraying the lens with solution.

27. A method of claim 17, wherein no pretreatment is applied to increase the charge density of the material.

28. A method of claim 17, wherein the method comprises repeating steps (a) to (f) between 5 and 20 times.

29. A method of claim 19, wherein this method comprises repeating steps (a) and (b) between 5 and 20 times.

30. An accessory for supporting an article, which comprises: (a) a core material having a dispersed plurality of transient or permanent charges on or near the surface of the material; and (b) a surface coating that includes a polyionic material that is bonded to the core material.

31. A mold for manufacturing an article, which comprises: (a) a core material having a dispersed plurality of transient or permanent charges on or near the surface of the material; and (b) a surface coating, including a polyionic maferial that is bonded to the core material.

32. A method for forming an article, and coating the article by transfer grafting a coating material from the mold where the article was produced, which comprises the steps of: (a) applying- Jin coating a poly material -ionic to a mold, contacting at least a portion of the mold with a solution of the poly-ionic material; (b) dosing a liquid molding material in the mold, thereby contacting the liquid molding material with the coating; and (c) allowing the coating of the mold to contact the liquid molding material, for a time sufficient for at least a portion of the coating to be transferred from the mold to the molding material; and (d) causing the liquid mold material to be cured, thereby forming a solid molded article having a polyionic coating.

33. A method for altering the surface of an article, which comprises the steps of: (a) applying a first coating of a poly-ionic material to an article, wherein the poly-ionic material includes functional groups; and (b) contacting the coated article with a second material that includes groups that are reactive with the functional groups of the polyionic material, thereby reacting and grafting the second material onto the polyionic coating.

34. A biomedical product, including a core material and surface coatings, wherein at least a portion of the surface of the product comprises: (a) a first coating of a polyionic material adhered to the core material by means of a scattered load distribution; and (b) a second material that chemically binds to the polyionic material.

35. An ophthalmic product, which comprises retaining in packaging: (a) a contact lens, - and (b) an ophthalmically compatible sterile solution, comprising: (i) a polyionic material; (ii) a tonicity adjusting agent; and (iii) water.

36. A method for producing an article having a core and a surface coating, which comprises the steps of: (a) contacting an article with a cationic polyionic material, thereby bonding the material polyionic cationic to the article; (b) contacting the article with an anionic polyionic material, thereby bonding the anionic polyionic material with the cationic polyionic material; (c) contacting the article with a polyallylamine gluconolactone, thereby bonding the polyallylamine gluconolactone to the anionic polyionic material.

37. A method of claim 36, wherein steps (b) and (c) are repeated a plurality of times.

38. A method of claim 36, wherein steps (b) and (c) are repeated from about 2 to 7 times.