CN112245664B - Shape memory polymer material for esophagus stent and preparation and application methods - Google Patents
Shape memory polymer material for esophagus stent and preparation and application methods Download PDFInfo
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- 210000003238 esophagus Anatomy 0.000 title abstract description 22
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- A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
- A61L31/00—Materials for other surgical articles, e.g. stents, stent-grafts, shunts, surgical drapes, guide wires, materials for adhesion prevention, occluding devices, surgical gloves, tissue fixation devices
- A61L31/04—Macromolecular materials
- A61L31/06—Macromolecular materials obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
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- A61L31/00—Materials for other surgical articles, e.g. stents, stent-grafts, shunts, surgical drapes, guide wires, materials for adhesion prevention, occluding devices, surgical gloves, tissue fixation devices
- A61L31/14—Materials characterised by their function or physical properties, e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
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- C08F299/00—Macromolecular compounds obtained by interreacting polymers involving only carbon-to-carbon unsaturated bond reactions, in the absence of non-macromolecular monomers
- C08F299/02—Macromolecular compounds obtained by interreacting polymers involving only carbon-to-carbon unsaturated bond reactions, in the absence of non-macromolecular monomers from unsaturated polycondensates
- C08F299/022—Macromolecular compounds obtained by interreacting polymers involving only carbon-to-carbon unsaturated bond reactions, in the absence of non-macromolecular monomers from unsaturated polycondensates from polycondensates with side or terminal unsaturations
- C08F299/024—Macromolecular compounds obtained by interreacting polymers involving only carbon-to-carbon unsaturated bond reactions, in the absence of non-macromolecular monomers from unsaturated polycondensates from polycondensates with side or terminal unsaturations the unsaturation being in acrylic or methacrylic groups
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Abstract
The invention discloses a shape memory polymer material for an esophagus stent and a preparation method thereof. The invention is prepared by carrying out polymerization reaction on hydrophilic crystallizable macromonomer, hydrophobic crystallizable macromonomer and cross-linking agent, wherein the mass part ratio of the hydrophilic crystallizable macromonomer, the hydrophobic crystallizable macromonomer and the cross-linking agent is as follows: 30-60 parts, 40-70 parts and 1-10 parts; the hydrophilic crystallizable macromonomer is polyethylene glycol diacrylate, and the hydrophobic crystallizable macromonomer is polytetrahydrofuran diacrylate; the cross-linking agent is pentaerythritol tetra-3-mercaptopropionate. The material disclosed by the invention is simple to prepare, light and soft in texture, degradable, capable of self-unfolding and adjusting in a human body environment and capable of slowly releasing medicines when being used as an esophagus stent material, and shows a relatively high application prospect.
Description
Technical Field
The invention belongs to the technical field of high polymer materials, and particularly relates to a shape memory polymer material for an esophagus stent, and a preparation method and an application method thereof.
Background
The esophagus cancer is a high-grade cancer in China, and the five-year survival rate of patients is lower than 15%. Esophageal stenting is an important treatment for patients with advanced esophageal cancer in a palliative manner. However, most of the conventional esophageal stent materials used in clinical practice are metal materials, and the esophageal stent materials can bring great pain to patients due to high rigidity after being implanted into human bodies. Metal stents are difficult to degrade and face the problem of being difficult to correct and retrieve once released in the human body. In addition, the traditional esophageal stent only can play a simple supporting role, can only relieve the narrow disease of the esophagus in a short time, is difficult to achieve the purposes of adjuvant therapy and inhibition of the regrowth of esophageal tumors, and has a limited effect on the improvement of the survival rate of patients.
The shape memory polymer material has wide application prospect in the fields of human tissue engineering and biomedicine, has the advantages of soft texture, high elasticity, high cost performance and the like, and is an ideal material for replacing a rigid esophageal stent. In addition, the shape memory polymer stent prepared by adopting the degradable material can be automatically degraded in a human body, so that the problem that the metal stent is difficult to recover is solved. The cross-linked network structure of the polymer is also beneficial to loading drug molecules, so that the polymer scaffold material has the effects of auxiliary treatment and tumor and pain inhibition while playing a mechanical supporting effect. However, most of the shape memory materials reported at present have more defects, which make them difficult to be applied to human body. First, the shape memory response temperature of most shape memory polymer materials is far higher than the normal body temperature of human body, so that the materials can not be triggered to expand by themselves after being implanted into the human body to realize the support of esophagus. The use of additional heating means both risks heat damage to the patient's tissue and increases the complexity of the stent implantation process. Secondly, the shape memory behavior of most current shape memory materials is irreversible, which makes it difficult to make precise adjustments of the implant site once the material triggers self-deployment after implantation into the body.
Therefore, the preparation of the polymer esophageal stent material which is degradable, self-expandable in human body environment, adjustable in implantation position and capable of slowly releasing the drug is a problem to be solved urgently.
Disclosure of Invention
In order to solve the defects of the prior art, the invention provides a shape memory polymer material for an esophagus stent and a preparation method and an application method thereof. The shape memory material has the capability of human body temperature response two-way shape memory and human body temperature and water response one-way triple shape memory. Besides, the material also has good stretchability and mechanical strength.
The technical scheme adopted by the invention is as follows:
a shape memory polymer material for esophagus stent
The shape memory polymer material is prepared by polymerization reaction of at least one hydrophilic crystallizable macromonomer, at least one hydrophobic crystallizable macromonomer and a crosslinking agent, wherein the melting point of the hydrophilic crystallizable macromonomer is higher than that of the hydrophobic crystallizable macromonomer. The parts of the hydrophilic crystallizable macromonomer, the hydrophobic crystallizable macromonomer and the crosslinking agent are respectively as follows by mass: 30-60 parts, 40-70 parts and 1-10 parts.
The hydrophilic crystallizable macromonomer is polyethylene glycol diacrylate, and the hydrophobic crystallizable macromonomer is polytetrahydrofuran diacrylate.
The cross-linking agent is pentaerythritol tetra-3-mercaptopropionate.
Second, preparation method of shape memory polymer material for esophagus stent
The polymer material is prepared by the following method:
1) quantitatively weighing hydrophilic crystallizable macromonomer, hydrophobic crystallizable macromonomer, cross-linking agent and ultraviolet photosensitizer, dissolving in solvent, and performing ultrasonic treatment to obtain precursor solution;
2) injecting the precursor solution into a mold, removing bubbles and sealing, and then carrying out cross-linking polymerization under ultraviolet irradiation;
3) and taking the crosslinked polymer out of the mold, and drying the crosslinked polymer in an oven at 40 ℃ in vacuum to constant weight to obtain the shape memory polymer material.
The hydrophilic crystallizable macromonomer is polyethylene glycol diacrylate, the hydrophobic crystallizable macromonomer is polytetrahydrofuran diacrylate, the crosslinking agent is pentaerythritol tetra-3-mercaptopropionate, the ultraviolet photosensitizer is benzoin dimethyl ether, and the solvent is a chloroform solvent.
In the step 1), by mass, 30-60 parts of polyethylene glycol diacrylate, 40-70 parts of polytetrahydrofuran diacrylate, 1-10 parts of pentaerythritol tetra-3-mercaptopropionate and 0.01-1 part of benzoin dimethyl ether are used.
Thirdly, a shape memory property control method of shape memory polymer material
The shape memory characteristic of the shape memory polymer material is a one-way shape memory characteristic of human body temperature response and water response, and the control method comprises the following steps:
s1, the shape memory polymer material's original shape being a permanent shape, heating the shape memory polymer material to 75 ℃ such that the crystalline phases in the interior of the shape memory polymer material are all melted;
s1, deforming the shape memory polymer material into a temporary shape A under the action of external force, and then cooling to 5-10 ℃ to form a fixed temporary shape A;
s2, deforming the shape memory polymer material from the temporary shape A to the temporary shape B under the action of external force at the temperature of 5-10 ℃, and then reducing the temperature to-20 ℃ to form a fixed temporary shape B;
s3, raising the temperature to 37 ℃, releasing the temporary shape B, and restoring the shape memory polymer material to the temporary shape A;
s4, the temporary shape A is released and the shape memory polymer material reverts from the temporary shape A back to the permanent shape by immersing the shape memory polymer material in water at 37 ℃.
Shape memory characteristic control method of shape memory polymer material
The shape memory characteristic of the shape memory polymer material is a human body temperature response bidirectional reversible shape memory characteristic, and the control method is as follows:
s1, taking the initial shape of the shape memory polymer material as a permanent shape, heating the shape memory polymer material to 75 ℃ to melt all crystal phases in the shape memory polymer material, deforming the shape memory polymer material into a temporary shape A through the action of external force, and fixing the temporary shape A of the shape memory polymer material after cooling to-20-15 ℃;
s2, raising the temperature to 37 ℃, and naturally restoring the shape memory polymer material from the temporary shape A to a temporary shape B between the temporary shape A and the permanent shape;
s3, reducing the temperature to-20-15 ℃, and naturally resetting the shape memory polymer material to the temporary shape A;
s4, repeating the steps S2 and S3, so that the temperature is switched between the temperature range of-20-15 ℃ and the temperature range of 37 ℃, and the reversible bidirectional natural change of the shape memory polymer material in the temporary shape A and the temporary shape B is realized.
Application of shape memory polymer material prepared by preparation method of shape memory polymer material
The shape memory polymer material is applied to an esophagus support.
The innovation of the invention is that the polymer material comprises two crystallizable chain segments with opposite hydrophilicity and hydrophobicity, the hydrophilic crystallizable chain segment has a melting point higher than the temperature of a human body, and an anisotropic network structure and internal stress are constructed for the polymer structure network through crystallization. At the same time, the high hydrophilicity of its crystalline phase imparts to the polymer a water-responsive shape memory property. The hydrophobic polytetrahydrofuran chain segment has a melting point lower than the temperature of a human body and can be used as a driving phase, so that the polymer has a two-way shape memory characteristic. Furthermore, the hydrophobic nature of the polytetrahydrofuran segment also ensures that the polytetrahydrofuran crystal phase is stable in aqueous environments and limits excessive swelling of the polymer network in human environments.
The hydrophilic crystallizable phase with the high melting point constructs a polymer network with anisotropy and internal stress through a crystallization mode, and at the moment, the hydrophobic crystallizable phase with the low melting point is used as a reversible driving phase to endow the polymer with the capability of switching between two shapes in a reciprocating way, so that the polymer has the characteristic of bidirectional shape memory of human body temperature response.
The polymer material of the invention is used as an esophagus stent, has the capabilities of self-unfolding, adjustable implantation position and slow release of drugs in human body environment, and simultaneously can show the characteristics of one-way triple shape memory of human body temperature and water response by means of ordered heating and water treatment.
The invention has the following beneficial effects:
1. the shape memory polymer esophageal stent material provided by the invention has the characteristics of human body temperature response bidirectional reversible shape memory and human body temperature and water response triple shape memory, and the polymer with the memory characteristics can be spontaneously unfolded after being implanted into a human body, so that the implantation position can be accurately adjusted, the defect that most shape memory materials reported at present are difficult to apply to the human body is overcome, and the shape memory polymer esophageal stent material has obvious advantages compared with most shape memory polymers reported at present.
2. The shape memory polymer esophageal stent material provided by the invention has the advantages of simple preparation process, easily available raw materials, light and soft texture and degradability, and can be automatically degraded in a human body to solve the problem that a metal stent is difficult to recover;
3. the shape memory polymer esophageal stent material provided by the invention has the mechanical properties of higher tensile stress, tensile strain, Young modulus and the like;
4. the shape memory polymer esophageal stent material provided by the invention has the capabilities of self-unfolding, adjustable implantation position and slow release of drugs in a human body environment when in use, and shows a higher application prospect.
Drawings
FIG. 1 is a chemical structural formula of polytetrahydrofuran diacrylate used in example 1.
FIG. 2 is a chemical structural formula of polyethylene glycol diacrylate used in example 1.
FIG. 3 is a DSC temperature rise profile of polytetrahydrofuran diacrylate and polyethylene glycol diacrylate used in example 1.
FIG. 4 is a DSC plot of temperature increase for the shape memory polymer material prepared in example 1.
FIG. 5 is a tensile stress-strain plot of the shape memory polymer material prepared in example 1.
FIG. 6 is a two-way reversible shape memory curve between-20 deg.C and 37 deg.C for the shape memory polymer material prepared in example 1.
FIG. 7 is a schematic diagram of a human body temperature and water response one-way triple shape memory network structure of the shape memory polymer material prepared in example 1.
FIG. 8 is a schematic diagram of the two-way shape memory of the shape memory polymer scaffold material prepared in this example when the temperature is raised and lowered between 0 ℃ and 37 ℃ in a cycling manner.
FIG. 9 is a schematic view showing the implantation of the shape memory polymer material prepared in example 1 when used as an esophageal stent.
Fig. 10 is a flow chart of the in vitro evaluation and operation of polymer esophageal stent implantation, position adjustment, drug release based on human temperature responsive two-way shape memory and human temperature and water responsive one-way triple shape memory.
Detailed Description
The present invention will be described in more detail with reference to specific examples, but the embodiments of the present invention are not limited thereto.
A shape memory polymer material for esophagus stent
The shape memory polymer material is a shape memory polymer network structure material prepared by polymerization reaction of at least one hydrophilic crystallizable macromonomer, at least one hydrophobic crystallizable macromonomer and a crosslinking agent, wherein the melting point of the hydrophilic crystallizable macromonomer is higher than that of the hydrophobic crystallizable macromonomer. The parts of the hydrophilic crystallizable macromonomer, the hydrophobic crystallizable macromonomer and the crosslinking agent are respectively as follows by mass: 30-60 parts, 40-70 parts and 1-10 parts.
The hydrophilic crystallizable macromonomer is polyethylene glycol diacrylate, and the chemical formula is shown in figure 2, and the hydrophobic crystallizable macromonomer is polytetrahydrofuran diacrylate, and the chemical formula is shown in figure 1.
The cross-linking agent is pentaerythritol tetra-3-mercaptopropionate.
The shape memory polymer material has two melting points, which are respectively between 5 and 25 ℃ and between 30 and 50 ℃.
Second, preparation method of shape memory polymer material for esophagus stent
The polymer material is prepared by the following method:
1) quantitatively weighing hydrophilic crystallizable macromonomer, hydrophobic crystallizable macromonomer, cross-linking agent and ultraviolet photosensitizer, dissolving in solvent, and performing ultrasonic treatment to obtain precursor solution;
2) injecting the precursor solution into a mold, removing bubbles and sealing, and then carrying out cross-linking polymerization under ultraviolet irradiation;
3) and taking the crosslinked polymer out of the mold, and drying the crosslinked polymer in an oven at 40 ℃ in vacuum to constant weight to obtain the shape memory polymer material.
The hydrophilic crystallizable macromonomer is polyethylene glycol diacrylate, the hydrophobic crystallizable macromonomer is polytetrahydrofuran diacrylate, the crosslinking agent is pentaerythritol tetra-3-mercaptopropionate, the ultraviolet photosensitizer is benzoin dimethyl ether, and the solvent is a chloroform solvent.
In the step 1), by mass, 30-60 parts of polyethylene glycol diacrylate, 40-70 parts of polytetrahydrofuran diacrylate, 1-10 parts of pentaerythritol tetra-3-mercaptopropionate and 0.01-1 part of benzoin dimethyl ether are used.
The shape memory polymer material has the characteristics of two-way shape memory in response to the human body temperature and one-way triple shape memory in response to the human body temperature and water.
The esophagus stent has the capabilities of self-unfolding, adjustable implantation position, compact implantation and slow release of medicines. The self-expanding capability of the esophageal stent is derived from the one-way shape memory characteristic of human body temperature response. The implanted position adjustability of the esophageal stent is derived from the temperature responsive two-way shape memory characteristics of the human body. The tight implantation and drug release capabilities of esophageal stents derive from their water-responsive one-way shape memory properties.
Thirdly, a shape memory property control method of shape memory polymer material
The shape memory characteristics of the shape memory polymer material comprise a human body temperature response bidirectional reversible shape memory characteristic and a human body temperature response and water response unidirectional shape memory characteristic.
The shape memory property of the shape memory polymer material is a one-way shape memory property of human body temperature response and water response, and the control method comprises the following steps:
s1, the shape memory polymer material's original shape being a permanent shape, heating the shape memory polymer material to 75 ℃ such that the crystalline phases in the interior of the shape memory polymer material are all melted;
s1, deforming the shape memory polymer material into a temporary shape A under the action of external force, then cooling to 5-10 ℃ to form a fixed temporary shape A, and at the moment, crystallizing the polyethylene glycol chain segment and using the polyethylene glycol chain segment as a cross-linking point to fix the temporary shape A;
s2, deforming the shape memory polymer material from the temporary shape A to the temporary shape B under the action of external force at the temperature of 5-10 ℃, then reducing the temperature to-20 ℃ to form a fixed temporary shape B, and at the moment, enabling the polytetrahydrofuran chain segment to crystallize and serve as a cross-linking point to fix the temporary shape B;
s3, increasing the temperature to 37 ℃, wherein the temporary shape B is released and the shape memory polymer material returns to the temporary shape A due to the melting of the polytetrahydrofuran crystalline phase;
s4, at 37 ℃ and by immersing the shape memory polymer material in water, the hydrophilic polyethylene glycol crystalline phase dissolves, the temporary shape A is released and the shape memory polymer material reverts from the temporary shape A to the permanent shape.
Shape memory characteristic control method of shape memory polymer material
The shape memory property of the shape memory polymer material is a human body temperature response bidirectional reversible shape memory property, and the control method is as follows:
s1, taking the initial shape of the shape memory polymer material as a permanent shape, heating the shape memory polymer material to 75 ℃ to melt all crystal phases in the shape memory polymer material, deforming the shape memory polymer material into a temporary shape A through the action of external force, and fixing the temporary shape A of the shape memory polymer material after cooling to-20-15 ℃;
s2, raising the temperature to 37 ℃, wherein the shape memory polymer material is naturally deformed from the temporary shape A to a temporary shape B between the temporary shape A and the permanent shape due to the melting of the crystalline phase of the polytetrahydrofuran chain segment;
s3, reducing the temperature to-20-15 ℃, wherein the polytetrahydrofuran chain segment is crystallized, and the shape memory polymer material is naturally reset to the temporary shape A;
s4, repeating the steps S2 and S3 to switch the temperature between the temperature range of-20-15 ℃ and the temperature range of 37 ℃, and realizing reversible bidirectional natural change of the shape memory polymer material in the temporary shape A and the temporary shape B without external force.
The esophagus stent made of the shape memory polymer material has the advantages of self-unfolding, adjustable implantation position, compact implantation and realization of slow release of the medicine. The self-expanding capability of the esophageal stent is derived from the one-way shape memory characteristic of human body temperature response. The implanted position adjustability of the esophageal stent is derived from the temperature responsive two-way shape memory characteristics of the human body. The tight implantation and drug release capabilities of esophageal stents derive from their water-responsive one-way shape memory properties.
Application of shape memory polymer material prepared by preparation method of shape memory polymer material
Use of a shape memory polymer material in an esophageal stent.
The examples of the invention are as follows:
example 1
331.0mg of polytetrahydrofuran diacrylate, 220.4mg of polyethylene glycol diacrylate, 45.8mg of pentaerythritol tetra-3-mercaptopropionate, and 5.5mg of benzoin dimethyl ether were dissolved in 1.1ml of chloroform solution. And after the uniform transparent precursor solution is obtained by ultrasonic treatment, injecting the precursor solution into a transparent mold, removing bubbles, and sealing. And (3) placing the mould under a 365nm ultraviolet lamp for crosslinking polymerization for 1.5h, taking the completely crosslinked polymer out of the mould, and drying the polymer in a drying oven at 40 ℃ in vacuum to constant weight to obtain the triple shape memory polymer material with the human body temperature response bidirectional reversible shape memory and the human body temperature and water response.
The polytetrahydrofuran diacrylate used in this example had a molecular weight of 2900g/mol and a melting point of 26.0 ℃. The molecular weight of the polyethylene glycol diacrylate used is 4000g/mol, the melting point is 56.3 ℃. FIG. 3 shows the DSC temperature rise curves of the polytetrahydrofuran diacrylate and the polyethylene glycol diacrylate used. As shown in FIG. 4, the shape memory polymer prepared exhibited two separate crystalline phases with two melting points. The lower melting point is 12.7 ℃, which is lower than the body temperature of a human body, the higher melting point is 40.6 ℃, which is higher than the body temperature of the human body, the crystalline phase with the melting point lower than 37 ℃ in the polymer network can be used as a driving phase of the two-way shape memory, and the crystalline phase with the melting point higher than 37 ℃ can be used for constructing the polymer anisotropic network and the internal stress.
The tensile stress-strain test is carried out on the shape memory polymer prepared in the embodiment, and the obtained tensile stress-strain curve is shown in fig. 5, so that the polymer has excellent stretchability and tensile strength, the breaking strain of the polymer exceeds 500%, and the tensile strength of the polymer exceeds 6MPa, which shows that the polymer has good mechanical properties.
FIG. 6 is a two-way shape memory curve of the shape memory polymer prepared in this example, which shows that the sample is elongated by applying a tensile stress to the sample at 75 deg.C, and then cooled to-20 deg.C, the strain is fixed, and the fixed strain remains stable after the stress is removed. Subsequently, the temperature is raised to 37 ℃, and the polymer network undergoes strain shrinkage in the direction of the internal stress due to the melting of the crystalline phase having a melting point below 37 ℃. When the temperature is reduced to-20 ℃ again, the polymer chain segment is oriented and crystallized, the polymer network generates the phenomenon of strain elongation caused by crystallization, and the polymer network generates strain elongation again. With the temperature switching between-20 ℃ and 37 ℃, the polymer exhibits a reversible strain of more than 23%.
FIG. 7 shows the human body temperature, water response one-way triple shape memory behavior of the shape memory polymer prepared in this example. It can be seen from the figure that the shape of the polymer sample with the permanent shape in the strip shape can be fixed in the temporary shape A by crystallization of the polyethylene glycol chain segment after the polymer sample with the permanent shape is shaped at 75 ℃ under the action of external force and the temperature is reduced to 5 ℃, then the polymer is shaped continuously at the temperature, and the polymer sample is fixed in the temporary shape B by inducing crystallization of the polytetrahydrofuran chain segment after the temperature is reduced to-20 ℃. And then heating to 37 ℃ and treating with water to induce the melting of the polytetrahydrofuran crystal phase and the dissolution of the polyethylene glycol crystal phase, so that the shape of the polymer is gradually recovered, and the polymer is respectively recovered to a temporary shape A and a permanent shape to show the temperature and water response one-way triple shape memory characteristics of the human body.
FIG. 8 is a schematic diagram of the two-way shape memory of the shape memory polymer scaffold material prepared in this example when the temperature is raised and lowered between 0 ℃ and 37 ℃ in a cycling manner. As can be seen, the cylindrical polymer stent material can realize reversible shrinkage and expansion through the operation mode of temperature reduction and temperature rise.
FIG. 9 is a schematic view showing the implantation of the shape memory polymer material prepared in this example as an esophageal stent. As can be seen, the polymer stent can fix the polymer in a contracted state by compressing and cooling after loading the drug molecules. The polymer can self-expand when the polymer stent is implanted into a human body and the shape is recovered due to the triggering of the temperature of the human body. Meanwhile, as the water in the human body can enter the polymer, the polymer can swell, and the polymer network is unfolded to release drug molecules, thereby playing the role of inhibiting the pain of patients and the growth of tumors.
FIG. 10 is a flowchart illustrating the in vitro evaluation and operation of the polymer material of this embodiment as an esophageal stent implantation, position adjustment, drug release. The glass tube is used for simulating the esophagus of a patient, white ball-shaped cotton simulates a lesion, and the insertion picture is a side view of the bracket. As can be seen, the polymer stent shaped to a contracted state at-20 ℃ can be easily implanted into the esophagus of a patient. After being implanted into the esophagus, the stent can be unfolded automatically at 37 ℃ and is changed from a contracted state to a cylindrical state to provide support for the esophagus.
The esophageal stent prepared by the invention has a reciprocating regulation function, the stent material can be induced to retract again by cooling to 0 ℃, and the retracted stent can be easily regulated to a proper implantation position by external force. And after the position of the bracket is adjusted, the cold source is removed, and the bracket responds to the temperature response of the human body again to perform self-expansion. And then, carrying out water treatment on the stent to simulate the humid environment of the human esophagus, further unfolding the esophagus after the water treatment, and finally realizing the purpose of compact implantation. In addition, the scaffold should be water-induced to swell, allowing release to the lesion site in the heavy polymer network of drug molecules loaded in the scaffold. When the stent was removed, the loaded red drug molecules were seen to diffuse to the lesion.
Example 2
275.4mg of polytetrahydrofuran diacrylate, 274.9mg of polyethylene glycol diacrylate, 43.9mg of pentaerythritol tetra-3-mercaptopropionate, and 5.5mg of benzoin dimethyl ether were dissolved in 1.1ml of chloroform solution. And after the uniform transparent precursor solution is obtained by ultrasonic treatment, injecting the precursor solution into a transparent mold, removing bubbles, and sealing. And (3) placing the mould under a 365nm ultraviolet lamp for crosslinking polymerization for 1.5h, taking the completely crosslinked polymer out of the mould, and drying the polymer in a drying oven at 40 ℃ in vacuum to constant weight to obtain the triple shape memory polymer material with the human body temperature response bidirectional reversible shape memory and the human body temperature and water response. The material shows good two-way shape memory characteristics between-20 ℃ and 37 ℃, and the reversible strain is 9.73%.
Example 3
386.7mg of polytetrahydrofuran diacrylate, 165.1mg of polyethylene glycol diacrylate, 46.8mg of pentaerythritol tetra-3-mercaptopropionate, and 5.5mg of benzoin dimethyl ether were dissolved in 1.1ml of chloroform solution. And after the uniform transparent precursor solution is obtained by ultrasonic treatment, injecting the precursor solution into a transparent mold, removing bubbles, and sealing. And (3) placing the mould under a 365nm ultraviolet lamp for crosslinking polymerization for 1.5h, taking the completely crosslinked polymer out of the mould, and drying the polymer in a drying oven at 40 ℃ in vacuum to constant weight to obtain the triple shape memory polymer material with the human body temperature response bidirectional reversible shape memory and the human body temperature and water response. The material shows good two-way shape memory characteristics between-20 ℃ and 37 ℃, and the reversible strain is 23.4%.
Claims (9)
1. A shape memory polymer material for an esophageal stent, characterized by: the hydrophilic crystallizable macromonomer is prepared by polymerization reaction of at least one hydrophilic crystallizable macromonomer, at least one hydrophobic crystallizable macromonomer and a crosslinking agent, and the melting point of the hydrophilic crystallizable macromonomer is higher than that of the hydrophobic crystallizable macromonomer.
2. A shape memory polymer material for an esophageal stent according to claim 1, wherein: the parts of the hydrophilic crystallizable macromonomer, the hydrophobic crystallizable macromonomer and the crosslinking agent are respectively as follows by mass: 30-60 parts, 40-70 parts and 1-10 parts.
3. A shape memory polymer material for an esophageal stent according to claim 1, wherein: the hydrophilic crystallizable macromonomer is polyethylene glycol diacrylate, and the hydrophobic crystallizable macromonomer is polytetrahydrofuran diacrylate.
4. A shape memory polymer material for an esophageal stent according to claim 1, wherein: the cross-linking agent is pentaerythritol tetra-3-mercaptopropionate.
5. A shape memory polymer material for an esophageal stent according to claim 1, wherein:
the hydrophilic crystallizable macromonomer is polyethylene glycol diacrylate, the hydrophobic crystallizable macromonomer is polytetrahydrofuran diacrylate, the crosslinking agent is pentaerythritol tetra-3-mercaptopropionate, the ultraviolet photosensitizer is benzoin dimethyl ether, and the solvent is a chloroform solvent.
6. A shape memory polymer material for an esophageal stent according to claim 5, wherein:
the adhesive comprises, by mass, 30-60 parts of polyethylene glycol diacrylate, 40-70 parts of polytetrahydrofuran diacrylate, 1-10 parts of pentaerythritol tetra-3-mercaptopropionate and 0.01-1 part of benzoin dimethyl ether.
7. A method of controlling the shape memory properties of a shape memory polymer material according to any one of claims 1 to 4, characterized in that:
the shape memory characteristic of the shape memory polymer material is a one-way shape memory characteristic of human body temperature response and water response, and the control method comprises the following steps:
s1, the shape memory polymer material's original shape being a permanent shape, heating the shape memory polymer material to 75 ℃ such that the crystalline phases in the interior of the shape memory polymer material are all melted;
s1, deforming the shape memory polymer material into a temporary shape A under the action of external force, and then cooling to 5-10 ℃ to form a fixed temporary shape A;
s2, deforming the shape memory polymer material from the temporary shape A to the temporary shape B under the action of external force at the temperature of 5-10 ℃, and then reducing the temperature to-20 ℃ to form a fixed temporary shape B;
s3, raising the temperature to 37 ℃, releasing the temporary shape B, and restoring the shape memory polymer material to the temporary shape A;
s4, the temporary shape A is released and the shape memory polymer material reverts from the temporary shape A back to the permanent shape by immersing the shape memory polymer material in water at 37 ℃.
8. A method of controlling the shape memory properties of a shape memory polymer material according to any one of claims 1 to 4, characterized in that:
the shape memory characteristic of the shape memory polymer material is a human body temperature response bidirectional reversible shape memory characteristic, and the control method is as follows:
s1, taking the initial shape of the shape memory polymer material as a permanent shape, heating the shape memory polymer material to 75 ℃ to melt all crystal phases in the shape memory polymer material, deforming the shape memory polymer material into a temporary shape A through the action of external force, and fixing the temporary shape A of the shape memory polymer material after cooling to-20-15 ℃;
s2, raising the temperature to 37 ℃, and naturally restoring the shape memory polymer material from the temporary shape A to a temporary shape B between the temporary shape A and the permanent shape;
s3, reducing the temperature to-20-15 ℃, and naturally resetting the shape memory polymer material to the temporary shape A;
s4, repeating the steps S2 and S3, so that the temperature is switched between the temperature range of-20-15 ℃ and the temperature range of 37 ℃, and the reversible bidirectional natural change of the shape memory polymer material in the temporary shape A and the temporary shape B is realized.
9. Use of a shape memory polymer material according to any of claims 1 to 4, wherein: the shape memory polymer material is applied to the preparation of an esophageal stent.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1805718A (en) * | 2003-06-13 | 2006-07-19 | 尼莫科学有限公司 | Stents |
| CN101421328A (en) * | 2006-03-14 | 2009-04-29 | Gkss研究中心盖斯特哈赫特有限公司 | Shape memory polymer with polyester and polyether segments and process for its preparation and programming |
| CN101554488A (en) * | 2009-05-22 | 2009-10-14 | 西南交通大学 | Preparation method and use method of biologically degradable shape memory tubular support stent |
| DE102009036817A1 (en) * | 2009-08-10 | 2011-02-17 | Acoredis Gmbh | Occlusion device, useful e.g. for closing the heart defects in a patient and other abnormal body openings, comprises mesh of fibers or film body of highly flexible, elastic materials, where the device is introduced through e.g. catheter |
| CN103992458A (en) * | 2014-06-11 | 2014-08-20 | 苏州大学 | Ultra-high strength polyurethane urea supermolecule hydrogel and preparation method thereof |
| CN107118310A (en) * | 2016-02-24 | 2017-09-01 | 香港纺织及成衣研发中心有限公司 | KAFO, for the KAFO shape memory high molecule material manufacture method |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10217351B3 (en) * | 2002-04-18 | 2004-02-12 | Mnemoscience Gmbh | Interpenetrating networks |
| DE10300271A1 (en) * | 2003-01-08 | 2004-07-22 | Mnemoscience Gmbh | Photosensitive polymer networks |
| DE102005053958A1 (en) * | 2005-11-11 | 2007-05-16 | Occlutech Gmbh | Medical self-expanding occlusion instrument for treating heart defects in patients by closing abnormal tissues openings comprises a network of thin threads made from a shape memory polymer composition |
| US9527947B2 (en) * | 2012-10-11 | 2016-12-27 | The Hong Kong Polytechnic University | Semi-crystalline shape memory polymer and production method thereof |
| CN107118313A (en) * | 2017-05-12 | 2017-09-01 | 浙江工业大学之江学院 | One kind has triple SME polymer and preparation method thereof |
| CN110183614A (en) * | 2019-06-27 | 2019-08-30 | 深圳市康勋新材科技有限公司 | Shape memory polymer foam material and its preparation method and application |
| CN110527036A (en) * | 2019-09-12 | 2019-12-03 | 临沂大学 | High molecular material and preparation method thereof with water-responsive bidirectional reversible shape memory function |
| CN111647127B (en) * | 2020-06-12 | 2021-11-30 | 成都工业职业技术学院 | Thermosetting shape memory polyurethane elastomer and preparation method thereof |
-
2020
- 2020-10-16 CN CN202011110307.9A patent/CN112245664B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1805718A (en) * | 2003-06-13 | 2006-07-19 | 尼莫科学有限公司 | Stents |
| CN101421328A (en) * | 2006-03-14 | 2009-04-29 | Gkss研究中心盖斯特哈赫特有限公司 | Shape memory polymer with polyester and polyether segments and process for its preparation and programming |
| CN101554488A (en) * | 2009-05-22 | 2009-10-14 | 西南交通大学 | Preparation method and use method of biologically degradable shape memory tubular support stent |
| DE102009036817A1 (en) * | 2009-08-10 | 2011-02-17 | Acoredis Gmbh | Occlusion device, useful e.g. for closing the heart defects in a patient and other abnormal body openings, comprises mesh of fibers or film body of highly flexible, elastic materials, where the device is introduced through e.g. catheter |
| CN103992458A (en) * | 2014-06-11 | 2014-08-20 | 苏州大学 | Ultra-high strength polyurethane urea supermolecule hydrogel and preparation method thereof |
| CN107118310A (en) * | 2016-02-24 | 2017-09-01 | 香港纺织及成衣研发中心有限公司 | KAFO, for the KAFO shape memory high molecule material manufacture method |
Non-Patent Citations (2)
| Title |
|---|
| Shape-Memory Hydrogels with Crystallizable Oligotetrahydrofuran Side Chains;Balk, Maria等;《MACROMOLECULAR SYMPOSIA》;20141130;第345卷(第1期);8-13 * |
| 双向形状记忆结晶聚合物及其复合材料的研究进展;黄淼铭;《高分子学报》;20170317(第4期);563-578 * |
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