CN1580102A - Method for preparing porous polymer film - Google Patents

Abstract

The invention discloses a method for preparing a porous polymer film. The purpose of the present invention is to provide a simple preparation method of a porous scaffold-a porous polymer membrane applied in the field of tissue engineering. The method for preparing a porous polymer film provided by the present invention is to cast a blend of polyhydroxybutyrate-valerate and elastomer in a pore-forming solvent to form a film, and then volatilize the pore-forming solvent to obtain a porous polymer film . The present invention does not use a pore-forming agent, nor any special equipment and devices, and can directly form a film to obtain a porous support that is conducive to cell growth and adhesion. The operation is simple and easy, and the cost is low. The diameter of the hole formed by the method is 1-10 μm, thereby overcoming the disadvantages of using a pore-forming agent in the traditional method that the hole is relatively large, accompanied by a sharp decline in mechanical properties and the like. The obtained porous polymer membrane has the characteristics of good uniformity, high porosity, good biocompatibility, good mechanical properties, etc., and has broad application prospects in the field of porous scaffolds for tissue engineering.

Description

A kind of method for preparing porous polymer film

technical field

The present invention relates to a process for the preparation of porous polymer membranes.

Background technique

Tissue engineering is an emerging multidisciplinary interdisciplinary science, whose purpose is to develop biological substitutes that can restore, maintain or improve the function of damaged tissues or organs, so as to repair and regenerate damaged tissues or organs. In the research of tissue engineering, the degradable polymer scaffold plays a central role. It not only provides structural support for specific cells, but also acts as a template to guide tissue regeneration and control tissue structure. Therefore, the scaffold must have good surface structure and biocompatibility, certain mechanical properties, good processing performance and complete biodegradability. An ideal tissue engineering scaffold should have the following characteristics: (1) The scaffold should be a three-dimensional porous network structure, the size of the pores should allow the survival of cells, and the pores should communicate with each other to facilitate the transfer of nutrients and cell metabolic waste; ( 2) It has good biocompatibility and biodegradability, and the degradation products can be completely absorbed or excreted by the organism, and the degradation rate should match the growth of new tissues; (3) The material should be structurally and functionally compatible with The natural extracellular matrix is similar, and has good biocompatibility, has no adverse effects on the surrounding tissue environment, and the surface structure should be suitable for cell adhesion and normal differentiation and proliferation; (4) has certain biomechanical properties and structure Stability, can withstand external force, and consistent with the tissue to be repaired; (5) The processing is convenient and efficient, easy to apply, and can adjust the physical, chemical, biological and mechanical properties of the material. The biocompatibility of tissue engineering scaffolds can be divided into surface biocompatibility and structural biocompatibility. Surface biocompatibility mainly depends on the choice of materials and surface modification process, while structural biocompatibility depends on The physical morphology of the scaffold, including its topology and the dimensions of the synergistic components, has an important impact on cell viability. Studies have shown that the shape, size and porosity of the pores in the scaffold directly affect the migration, differentiation and proliferation of the planted cells, and these factors vary greatly with the different preparation methods, and the processing quality is directly related to the optimal function of the new tissue. inferior.

Currently, there are five main techniques for preparing tissue engineering scaffolds: 1) solution casting, pore-forming agent leaching. The used pore-forming agent content of this method is low, owing to adopting solution to cast in vessel, thereby cause pore-forming agent to sink, pore distribution is uneven and upper and lower surface form difference appears; 2) three-dimensional layering method. A three-dimensional scaffold is formed by preparing a porous membrane and then bonding the layers together with a solvent. The process of this method is complex, and in the bonding process, the holes of the bonding part are closed, thereby forming an interface and making the internal shape of the material uneven; 3) melt processing method. In this method, above the melting point of the polymer, the pore-forming agent and the polymer are blended and extruded into the mold, and cooled to obtain a porous scaffold of a predetermined shape. The disadvantage of this method is that in the extruder, due to the large difference in density between the melt and the pore-forming agent, it is difficult to mix uniformly. Moreover, some polymers, especially biodegradable polymers, are easily thermally degraded during melt processing; 4) phase separation method. In this method, the solution mixture is cooled below the melting point of the solvent to produce phase separation, and then dried in a vacuum to obtain a porous scaffold. The disadvantage of this method is that the resulting pore size is generally below 100 microns, and it is difficult to control; 5) High-pressure carbon dioxide method. In this method, a porous scaffold is formed by exposing a shaped polymer to high-pressure carbon dioxide and releasing the carbon dioxide dissolved in the polymer by decompression. The disadvantage of this method is that the pores formed are closed.

It can be seen from the above pore-forming methods that method 1) uses a pore-forming agent. Although this method can obtain a porous scaffold with a large pore diameter range and adjustable porosity, the pore-forming agent cannot be completely removed. Pore-forming agents are extremely unfavorable to cell adhesion and growth during cell culture; while other pore-forming methods use special equipment and are complicated to operate.

Contents of the invention

The purpose of the present invention is to provide a simple preparation method of a porous scaffold-a porous polymer membrane applied in the field of tissue engineering.

In the method for preparing a porous polymer film provided by the invention, the blend solution of polyhydroxybutyrate-valerate and elastomer in a pore-forming solvent is flow-cast to form a film, and the porous polymer film is obtained after the pore-forming solvent is volatilized.

Its preparation process specifically includes the following steps:

1) After mixing polyhydroxybutyrate-valerate (PHB-HV) and elastomer, add a pore-forming solvent, heat, condense, and reflux to prepare a uniform solution;

2) Cool the prepared solution and pour it into a pair of evaporating dishes, fasten the upper and lower evaporating dishes, and volatilize the pore-forming solvent;

3) After the pore-forming solvent evaporates, place the evaporating dish in a vacuum oven for vacuum drying;

4) Take the evaporating dish out of the vacuum oven and remove the film to obtain a porous polymer film.

Wherein, the elastomer is preferably a biodegradable elastomer material, usually polyurethane (PU), polydimethyl terephthalate (PEGT-PBT), polybutylene succinate (PBS) or carbon dioxide - Propylene oxide copolymer (poly(carbonioxide-co-propylene oxide)), etc., the weight ratio of polyhydroxybutyrate-valerate to elastomer is 90:10-10:90.

The pore-forming solvent is usually chloroform or methylene chloride, and its dosage is 10-30 ml of pore-forming solvent per 1 g of the mixture of polyhydroxybutyrate-valerate and elastomer.

During the preparation, the diameter of the evaporating dish can be 4cm-16cm to control the diameter of the obtained film.

The present invention does not use a pore-forming agent, nor any special equipment and devices, and can directly form a film to obtain a porous support that is conducive to cell growth and adhesion. The operation is simple and easy, and the cost is low. The diameter of the pores formed by this method is 1-10 μm, and the porous membrane cannot see the pores macroscopically, so there are no defects on the membrane, which overcomes the large pores obtained by using the pore-forming agent in the traditional method, and the existence of micropores on the macroscopic basis is accompanied by mechanical problems. The disadvantage of a sharp decrease in mechanical properties. The porous polymer film of the present invention is prepared with an ASTM D638 standard mold to prepare a dumbbell-shaped tensile sample, the length of the measuring part of the sample is 20mm, and the width is 4mm. The universal material testing machine produced by British Instron Company was used to test the mechanical properties under the condition of tensile speed of 10mm/min, and the mechanical properties parameters such as tensile strength, yield strength and elongation at break were tested respectively. Compared with the test results of the porous membrane obtained by the traditional film casting method, the mechanical properties of the porous membrane obtained by the method of the present invention are far superior to those obtained by the traditional method. The porous polymer membrane prepared by the method of the invention has the characteristics of good uniformity, high porosity, good biocompatibility, etc., and has broad application prospects in the field of porous scaffolds for tissue engineering.

Detailed ways

Embodiment 1, the preparation of porous polymer film

1) Add 2.7g of polyhydroxybutyrate-valerate (PHB-HV), 0.3g of polyurethane, and 70ml of chloroform into a flask, heat at 100-120°C under stirring conditions, condense, and reflux for 15 minutes to prepare a uniform solution;

2) Using the method of cast film formation, cool the solution prepared in 1) to room temperature and pour it into a pair of evaporating dishes with a diameter of 12 cm, fasten the upper and lower evaporating dishes, and slowly volatilize the chloroform;

3) After the solvent is completely evaporated, place the entire evaporating dish in a vacuum oven and dry it in vacuum for 48 hours;

4) Take the evaporating dish out of the vacuum oven and remove the film to obtain a polymer film with a porous structure.

The polymer membrane obtained by the method has a pore diameter of 1-10 μm and a porosity of about 70%.

Embodiment 2, the preparation of porous polymer film

1) Add 2.1g of PHB-HV, 0.9g of polyurethane, and 80ml of chloroform into the flask, heat at 100-120°C under stirring conditions, condense, and reflux for 15 minutes to prepare a uniform solution;

2) Using the method of cast film formation, cool the solution prepared in 1) to room temperature and pour it into a pair of evaporating dishes with a diameter of 16 cm, fasten the upper and lower evaporating dishes, and slowly volatilize the chloroform;

3) After the solvent is completely evaporated, place the entire evaporating dish in a vacuum oven and dry it in vacuum for 48 hours;

4) Take the evaporating dish out of the vacuum oven and remove the film to obtain a polymer film with a porous structure.

The porosity of the polymer film obtained by the method is 1-10 μm, and the porosity is about 70%.

Embodiment 3, the preparation of porous polymer film

1) Add 1.5g of PHB-HV, 1.5g of polyurethane, and 50ml of chloroform into the flask, heat at 100-120°C under stirring conditions, condense, and reflux for 15 minutes to prepare a uniform solution;

2) Using the method of cast film formation, cool the solution prepared in 1) to room temperature and pour it into a pair of evaporating dishes with a diameter of 10 cm, fasten the upper and lower evaporating dishes, and slowly volatilize the chloroform;

3) After the solvent is completely evaporated, place the entire evaporating dish in a vacuum oven and dry it in vacuum for 48 hours;

4) Take the evaporating dish out of the vacuum oven and remove the film to obtain a polymer film with a porous structure.

The porosity of the polymer film obtained by the method is 1-10 μm, and the porosity is about 70%.

Embodiment 4, the preparation of porous polymer film

1) Add 0.9g of PHB-HV, 2.1g of polyurethane, and 40ml of chloroform into the flask, heat at 100-120°C under stirring conditions, condense, and reflux for 15 minutes to prepare a uniform solution;

2) Using the casting method, cool the solution prepared in 1) to room temperature and pour it into a pair of evaporating dishes with a diameter of 9 cm, fasten the upper and lower evaporating dishes, and slowly volatilize the chloroform;

3) After the solvent is completely evaporated, place the entire evaporating dish in a vacuum oven and dry it in vacuum for 48 hours;

4) Take the evaporating dish out of the vacuum oven and remove the film to obtain a polymer film with a porous structure.

The porosity of the polymer film obtained by the method is 1-10 μm, and the porosity is about 70%.

Embodiment 5, the preparation of porous polymer film

1) Add 0.3g of PHB-HV, 2.7g of polyurethane, and 30ml of chloroform into the flask, heat at 100-120°C under stirring conditions, condense, and reflux for 15 minutes to prepare a uniform solution;

2) Using the method of cast film formation, cool the solution prepared in 1) to room temperature and pour it into a pair of evaporating dishes with a diameter of 6 cm, fasten the upper and lower evaporating dishes, and slowly volatilize the chloroform;

3) After the solvent is completely evaporated, place the entire evaporating dish in a vacuum oven and dry it in vacuum for 48 hours;

4) Take the evaporating dish out of the vacuum oven and remove the film to obtain a polymer film with a porous structure.

The porosity of the polymer film obtained by the method is 1-10 μm, and the porosity is about 70%.

Embodiment 6, the preparation of porous polymer film

1) Add 2.7g PHB-HV, 0.3g polydimethyl terephthalate (PEGT-PBT), 90ml dichloromethane into the flask, heat at 100-120℃ under stirring condition, condense and reflux for 15 minutes to prepare a homogeneous The solution;

2) Using the method of cast film formation, cool the solution prepared in 1) to room temperature and pour it into a pair of evaporating dishes with a diameter of 12 cm, fasten the upper and lower evaporating dishes, and slowly volatilize the chloroform;

3) After the solvent is completely evaporated, place the entire evaporating dish in a vacuum oven and dry it in vacuum for 48 hours;

4) Take the evaporating dish out of the vacuum oven and remove the film to obtain a polymer film with a porous structure.

The porosity of the polymer film obtained by the method is 1-10 μm, and the porosity is about 70%.

Embodiment 7, the preparation of porous polymer film

1) Add 2.1gPHB-HV, 0.9gPEGT-PBT, and 80ml chloroform into the flask, heat at 100-120°C under stirring conditions, condense, and reflux for 15 minutes to prepare a uniform solution;

2) Using the method of cast film formation, cool the solution prepared in 1) to room temperature and pour it into a pair of evaporating dishes with a diameter of 16 cm, fasten the upper and lower evaporating dishes, and slowly volatilize the chloroform;

3) After the solvent is completely evaporated, place the entire evaporating dish in a vacuum oven and dry it in vacuum for 48 hours;

4) Take the evaporating dish out of the vacuum oven and remove the film to obtain a polymer film with a porous structure.

The porosity of the polymer film obtained by the method is 1-10 μm, and the porosity is about 70%.

Embodiment 8, the preparation of porous polymer film

1) Add 1.5gPHB-HV, 1.5gPEGT-PBT, and 50ml chloroform into the flask, heat at 100-120°C under stirring conditions, condense, and reflux for 15 minutes to prepare a uniform solution;

2) Using the method of cast film formation, cool the solution prepared in 1) to room temperature and pour it into a pair of evaporating dishes with a diameter of 10 cm, fasten the upper and lower evaporating dishes, and slowly volatilize the chloroform;

3) After the solvent is completely evaporated, place the entire evaporating dish in a vacuum oven and dry it in vacuum for 48 hours;

4) Take the evaporating dish out of the vacuum oven and remove the film to obtain a polymer film with a porous structure.

The porosity of the polymer film obtained by the method is 1-10 μm, and the porosity is about 70%.

Embodiment 9, the preparation of porous polymer film

1) Add 0.9gPHB-HV, 2.1gPEGT-PBT, and 40ml chloroform into the flask, heat at 100-120°C under stirring conditions, condense, and reflux for 15 minutes to prepare a uniform solution;

2) Using the casting method, cool the solution prepared in 1) to room temperature and pour it into a pair of evaporating dishes with a diameter of 9 cm, fasten the upper and lower evaporating dishes, and slowly volatilize the chloroform;

3) After the solvent is completely evaporated, place the entire evaporating dish in a vacuum oven and dry it in vacuum for 48 hours;

4) Take the evaporating dish out of the vacuum oven and remove the film to obtain a polymer film with a porous structure.

The porosity of the polymer film obtained by the method is 1-10 μm, and the porosity is about 70%.

Embodiment 10, the preparation of porous polymer film

1) Add 0.3gPHB-HV, 2.7gPEGT-PBT, and 30ml chloroform into the flask, heat at 100-120°C under stirring conditions, condense, and reflux for 15 minutes to prepare a uniform solution;

2) Using the method of cast film formation, cool the solution prepared in 1) to room temperature and pour it into a pair of evaporating dishes with a diameter of 6 cm, fasten the upper and lower evaporating dishes, and slowly volatilize the chloroform;

3) After the solvent is completely evaporated, place the entire evaporating dish in a vacuum oven and dry it in vacuum for 48 hours;

4) Take the evaporating dish out of the vacuum oven and remove the film to obtain a polymer film with a porous structure.

The porosity of the polymer film obtained by the method is 1-10 μm, and the porosity is about 70%.

Embodiment 11, the preparation of porous polymer film

1) Add 2.7g of PHB-HV, 0.3g of polybutylene succinate (PBS), and 90ml of dichloromethane into the flask, heat at 100-120°C under stirring conditions, condense, and reflux for 15 minutes to prepare a uniform solution ;

2) Using the method of cast film formation, cool the solution prepared in 1) to room temperature and pour it into a pair of evaporating dishes with a diameter of 12 cm, fasten the upper and lower evaporating dishes, and slowly volatilize the chloroform;

3) After the solvent is completely evaporated, place the entire evaporating dish in a vacuum oven and dry it in vacuum for 48 hours;

4) Take the evaporating dish out of the vacuum oven and remove the film to obtain a polymer film with a porous structure.

The porosity of the polymer film obtained by the method is 1-10 μm, and the porosity is about 70%.

Embodiment 12, the preparation of porous polymer film

1) Add 2.1gPHB-HV, 0.9gPBS, and 80ml chloroform into the flask, heat at 100-120°C under stirring conditions, condense, and reflux for 15 minutes to prepare a uniform solution;

2) Using the method of cast film formation, cool the solution prepared in 1) to room temperature and pour it into a pair of evaporating dishes with a diameter of 16 cm, fasten the upper and lower evaporating dishes, and slowly volatilize the chloroform;

3) After the solvent is completely evaporated, place the entire evaporating dish in a vacuum oven and dry it in vacuum for 48 hours;

4) Take the evaporating dish out of the vacuum oven and remove the film to obtain a polymer film with a porous structure.

The porosity of the polymer film obtained by the method is 1-10 μm, and the porosity is about 70%.

Embodiment 13, the preparation of porous polymer film

1) Add 1.5gPHB-HV, 1.5gPBS, and 50ml chloroform into the flask, heat at 100-120°C under stirring conditions, condense, and reflux for 15 minutes to prepare a uniform solution;

2) Using the method of cast film formation, cool the solution prepared in 1) to room temperature and pour it into a pair of evaporating dishes with a diameter of 10 cm, fasten the upper and lower evaporating dishes, and slowly volatilize the chloroform;

3) After the solvent is completely evaporated, place the entire evaporating dish in a vacuum oven and dry it in vacuum for 48 hours;

4) Take the evaporating dish out of the vacuum oven and remove the film to obtain a polymer film with a porous structure.

The porosity of the polymer film obtained by the method is 1-10 μm, and the porosity is about 70%.

Embodiment 14, the preparation of porous polymer film

1) Add 0.9gPHB-HV, 2.1gPBS, and 40ml of dichloromethane into the flask, heat at 100-120°C under stirring conditions, condense, and reflux for 15 minutes to prepare a uniform solution;

2) Using the casting method, cool the solution prepared in 1) to room temperature and pour it into a pair of evaporating dishes with a diameter of 9 cm, fasten the upper and lower evaporating dishes, and slowly volatilize the chloroform;

3) After the solvent is completely evaporated, place the entire evaporating dish in a vacuum oven and dry it in vacuum for 48 hours;

4) Take the evaporating dish out of the vacuum oven and remove the film to obtain a polymer film with a porous structure.

The porosity of the polymer film obtained by the method is 1-10 μm, and the porosity is about 70%.

Embodiment 15, the preparation of porous polymer film

1) Add 0.3gPHB-HV, 2.7gPBS, and 30ml chloroform into the flask, heat at 100-120°C under stirring conditions, condense, and reflux for 15 minutes to prepare a uniform solution;

2) Using the method of cast film formation, cool the solution prepared in 1) to room temperature and pour it into a pair of evaporating dishes with a diameter of 6 cm, fasten the upper and lower evaporating dishes, and slowly volatilize the chloroform;

3) After the solvent is completely evaporated, place the entire evaporating dish in a vacuum oven and dry it in vacuum for 48 hours;

4) Take the evaporating dish out of the vacuum oven and remove the film to obtain a polymer film with a porous structure.

The porosity of the polymer film obtained by the method is 1-10 μm, and the porosity is about 70%.

Embodiment 16, the preparation of porous polymer film

1) Add 0.3g of PHB-HV, 2.7g of carbon dioxide-propylene oxide copolymer, and 50ml of chloroform into the flask, heat at 100-120°C under stirring conditions, condense, and reflux for 15 minutes to prepare a uniform solution;

2) Using the method of cast film formation, cool the solution prepared in 1) to room temperature and pour it into a pair of evaporating dishes with a diameter of 10 cm, fasten the upper and lower evaporating dishes, and slowly volatilize the chloroform;

3) After the solvent is completely evaporated, place the entire evaporating dish in a vacuum oven and dry it in vacuum for 48 hours;

4) Take the evaporating dish out of the vacuum oven and remove the film to obtain a polymer film with a porous structure.

The porosity of the polymer film obtained by the method is 1-10 μm, and the porosity is about 70%.

Example 17, Biocompatibility experiment of the porous polymer membrane of the present invention

The following biological properties were evaluated with the porous polymer membrane obtained in Example 1 of the present invention: first, rabbit vascular smooth muscle cells were cultured by the tissue block attachment method, passaged and identified. Vigorously growing smooth muscle cells from the 2nd to 4th passages were planted on porous membranes with a diameter of 6 mm and porous membranes obtained by cast film formation at a density of 4.5×10 ⁶ /cm ² , and placed in 96-well plates for culture. On the 1st, 3rd, 5th, and 7th day of culture, observe with an inverted microscope, stain with toluidine blue, and measure MTT. Observing the cell adhesion situation on the support with an inverted microscope, the results show that the cell adhesion of the porous membrane obtained in Example 1 of the present invention is better, and the MTT value of the porous membrane obtained by the method of the present invention is about 0.549, which is higher than that of the traditional casting method. The MTT value (0.327) of the porous membrane obtained by the membrane method shows that the porous membrane obtained by the pore forming method of the present invention is more suitable for the growth and reproduction of vascular smooth muscle cells.

Claims (8)

1, a kind of method for preparing apertured polymeric film, the blended liquid casting film-forming in the pore-forming solvent with polyhydroxybutyrate-valerate and elastomerics behind the volatilization pore-forming solvent, obtains apertured polymeric film.

2, method according to claim 1, it is characterized in that: preparation process comprises the steps;

1) with after polyhydroxybutyrate-valerate and the elastomerics mixing, adds the pore-forming solvent,, be mixed with uniform solution through heating, condensation, backflow;

2) pour in the secondary furnace pot after the solution cooling that will prepare, furnace pot is up and down fastened, wherein pore-forming solvent volatilizees;

3) after the pore-forming solvent evaporates, furnace pot is inserted vacuum-drying in the vacuum drying oven;

4) furnace pot is taken out from vacuum drying oven, demoulding, obtain having apertured polymeric film.

3, method according to claim 1 and 2 is characterized in that: described elastomerics is a urethane, poly-to dioctyl phthalate dimethyl ester, poly butylene succinate or carbon dioxide-epoxy propane copolymer.

4, method according to claim 1 and 2 is characterized in that: described polyhydroxybutyrate-valerate and elastomeric ratio of weight and number are 90: 10-10: 90.

5, method according to claim 1 and 2 is characterized in that: the envelope-bulk to weight ratio (milliliter/gram) of described pore-forming solvent and polyhydroxybutyrate-valerate and elastomeric mixture is 10-30: 1.

6, method according to claim 1 and 2 is characterized in that: described pore-forming solvent is trichloromethane or methylene dichloride.

7, method according to claim 1 and 2 is characterized in that: the diameter of described furnace pot is 4cm-16cm.

8, method according to claim 1 and 2 is characterized in that: the described vacuum drying time is 48 hours.