阅读说明：本技术 一种细菌纤维素-聚氨酯复合材料及其制备方法和应用 (Bacterial cellulose-polyurethane composite material and preparation method and application thereof ) 是由 钟宇光 钟春燕 于 2020-04-17 设计创作，主要内容包括：本发明提供一种细菌纤维素-聚氨酯复合材料及其制备方法和应用。制备方法包括：将细菌纤维素微纤进行有机溶剂交换处理,获得不同浓度的细菌纤维素微纤的复合物A和复合物B；于油浴条件下加入聚合物多元醇和二异氰酸酯类化合物进行加聚反应,反应得到细菌纤维素复合聚氨酯泡沫预聚体；然后进行固化得到该细菌纤维素-聚氨酯复合材料。本发明采用细菌纤维素微纤与聚氨酯泡沫材料复合,显著提高了复合材料的力学性能；细菌纤维素纳米纤维表面大量羟基有效加强了复合材料的亲水性能及吸水能力；同时细菌纤维素良好的组织亲和能力可以改善聚氨酯材料的生物相容性。(The invention provides a bacterial cellulose-polyurethane composite material and a preparation method and application thereof. The preparation method comprises the following steps: carrying out organic solvent exchange treatment on the bacterial cellulose microfiber to obtain a compound A and a compound B of the bacterial cellulose microfiber with different concentrations; adding polymer polyol and diisocyanate compounds under the oil bath condition for addition polymerization reaction to obtain a bacterial cellulose composite polyurethane foam prepolymer; and then curing to obtain the bacterial cellulose-polyurethane composite material. The invention adopts the bacterial cellulose microfiber and the polyurethane foam material for compounding, thereby obviously improving the mechanical property of the composite material; the large amount of hydroxyl on the surface of the bacterial cellulose nanofiber effectively enhances the hydrophilic property and the water absorption capacity of the composite material; meanwhile, the good tissue affinity of the bacterial cellulose can improve the biocompatibility of the polyurethane material.)

1. A preparation method of a bacterial cellulose-polyurethane composite material comprises the following steps:

carrying out organic solvent exchange treatment on the bacterial cellulose microfiber to obtain a compound A and a compound B of the bacterial cellulose microfiber with different concentrations;

the composite A comprises 30-50 wt% of completely dehydrated bacterial cellulose microfiber and the balance of organic solvent, wherein the weight of the composite A is 100 wt%; the compound B comprises 15-30 wt% of partially dehydrated bacterial cellulose microfiber and the balance of organic solvent, wherein the weight part of the compound B is 100 wt%; wherein the partially dehydrated bacterial cellulose microfiber contains 5-10 wt% of water;

mixing the compound A and the compound B according to the volume ratio of 1 (2-5), adding polymer polyol and diisocyanate compounds under the oil bath condition for addition polymerization reaction, and reacting to obtain a bacterial cellulose composite polyurethane foam prepolymer; curing the mixture to obtain a bacterial cellulose-polyurethane composite material;

wherein the weight ratio of the polymer polyol to the diisocyanate compound is 1: (0.1 to 0.2); the polymer polyol accounts for 20% -60% of the total weight of the compound A and the compound B.

2. The method according to claim 1, further comprising a step of purifying and homogenizing the bacterial cellulose obtained by the fermentation of the strain to obtain bacterial cellulose microfibrils; wherein the strain comprises one or more of Acetobacter xylinum, Rhizobium, Sarcina, Pseudomonas, Achromobacter, Alcaligenes, Aerobacter, and Azotobacter.

3. The method according to claim 1, further comprising a step of purifying and homogenizing the bacterial cellulose obtained by the fermentation of the strain to obtain bacterial cellulose microfibrils; the method for purifying the bacterial cellulose comprises the following steps:

washing the bacterial cellulose in a sodium hydroxide aqueous solution with the mass percentage of 4-8% for 4-6 h at the temperature of 70-100 ℃, and repeatedly washing the bacterial cellulose to be neutral by using distilled water to remove mycoprotein on the bacterial cellulose and residual culture medium adhered to a cellulose membrane, thereby obtaining the purified bacterial cellulose.

4. The method of claim 3, wherein the bacterial cellulose is homogenized by:

homogenizing the purified bacterial cellulose for 5-10 min by adopting a high-speed dispersion machine at the rotating speed of 5000-25000 rpm to obtain the bacterial cellulose microfiber.

5. The method according to claim 1, wherein the bacterial cellulose microfibers have a length of 0.1 to 10 μm and a diameter of 50 to 100 nm.

6. The method of claim 1, wherein the organic solvent exchange treatment is performed by:

soaking the bacterial cellulose microfiber in absolute ethyl alcohol, and controlling the soaking time for 8-12h to obtain completely dehydrated bacterial cellulose microfiber and controlling the soaking time for 3-6h to obtain partially dehydrated bacterial cellulose microfiber;

soaking the completely dehydrated bacterial cellulose microfiber in an organic solvent for 48-72 hours to obtain a compound A;

and (3) soaking the partially dehydrated bacterial cellulose microfiber in an organic solvent for 12-48 h to obtain a compound B.

7. The method of claim 1 or 6, wherein the organic solvent comprises a combination of one or more of ethyl glycol acetate, ethyl acetate, butyrolactone, acetic acid and acetone.

8. The process according to claim 1, wherein the addition polymerization is carried out under the conditions: carrying out oil bath at a constant temperature of 70-80 ℃ for 60-90 min;

preferably, the polymer polyol comprises a combination of one or more of polyethylene glycol, polypropylene oxide, propylene glycol and diethylene glycol.

9. The method of claim 1, wherein the curing of the bacterial cellulose composite polyurethane foam prepolymer is performed by:

adding a curing assistant into the bacterial cellulose composite polyurethane foam prepolymer, uniformly stirring, then adding a diisocyanate compound and water, uniformly stirring to obtain a mixture, and then curing to obtain a bacterial cellulose-polyurethane composite material;

the amount of the curing assistant is 0.5-2.6 wt% of the amount of the bacterial cellulose composite polyurethane foam prepolymer;

the dosage ratio of the diisocyanate compound to water is (20-40): (2-5);

in the curing process, the using amount of the diisocyanate compound is 20-50% of that of the polymer polyol;

preferably, the diisocyanate compound comprises one or more of toluene diisocyanate, diphenylmethane diisocyanate and isophorone diisocyanate;

preferably, the curing aid comprises a catalyst, a cell opener, and a stabilizer;

the catalyst comprises one or more of triethylene diamine, dimethyl ethanolamine, dibutyltin dilaurate and stannous octoate;

the cell opener comprises one or more of a combination of cell opener silicone oil, silicone oil 6070 and polybutadiene diol;

the stabilizer comprises one or more of organic silicon surfactant, sodium cocoamphoacetate, sodium lauroamphoacetate and disodium lauroamphodiacetate.

10. The method of claim 9, wherein the amount of the catalyst is 0.3-1.5 wt% of the amount of the bacterial cellulose composite polyurethane foam prepolymer; the using amount of the pore-forming agent is 0.1-1 wt% of that of the bacterial cellulose composite polyurethane foam prepolymer; the dosage of the stabilizer is 0.1-0.5 wt% of the dosage of the bacterial cellulose composite polyurethane foam prepolymer.

11. The method of claim 9, wherein the curing is performed by placing the uniformly mixed mixture in a mold and standing the mold at room temperature for 2-7 days.

12. A bacterial cellulose-polyurethane composite material comprises at least two layers of a macroporous layer and a microporous layer, wherein the pore diameter of the macroporous layer is 100-500 mu m, the porosity is 70-90%, and the thickness is 0.5-1 cm; the aperture of the microporous layer is 10-80 mu m, and the porosity is 60% -80%; the thickness is 0.1-0.3 cm.

13. The bacterial cellulose-polyurethane composite material according to claim 12, which is prepared by the preparation method according to any one of claims 1 to 11.

14. The bacterial cellulose-polyurethane composite material according to claim 12, wherein the mass ratio of the bacterial cellulose microfibers in the composite material is 20-40 wt%.

15. Use of the bacterial cellulose-polyurethane composite material according to any one of claims 12 to 14 in human body repair materials, intelligent drug release materials and tissue engineering materials.

Technical Field

The invention belongs to the technical field of skin repair, and relates to a bacterial cellulose-polyurethane composite material with a gradient structure, and a preparation method and application thereof.

Background

The healing process of a wound is a continuous dynamic process, which is the process of cell-to-cell, cell-to-cell matrix, and interaction with soluble mediators. Clinical wound healing is mainly wound dressing, and with popularization of wet therapy theory and practice, high-performance wet dressing with moisture absorption function is increasingly emphasized in the field of world medical treatment and health.

The currently clinically used dressings can be classified into bacterial cellulose dressings, polyurethane dressings and the like according to different materials.

The bacterial cellulose is a high molecular compound formed by connecting glucose by beta-1, 4-glucoside chains, is used as an excellent biological material, and has unique physical and chemical properties: the bacterial cellulose has a natural three-dimensional nano network structure; high tensile strength and modulus of elasticity; high hydrophilicity, good air permeability, water absorption and permeability, extraordinary water holding capacity and high wet strength. In addition, a large number of researches show that the bacterial cellulose has good in vivo and in vitro biocompatibility and biodegradability, so that the bacterial cellulose can be applied to the field of biomedicine. The adoption of pure bacterial cellulose hydrogel as a dressing has been reported abroad, and the bacterial cellulose hydrogel is already industrially used in clinic. Therefore, the bacterial cellulose hydrogel is used as a base material of the dressing, and the wound exudate and metabolites can be continuously and effectively absorbed on the basis of ensuring the biological safety by utilizing the water absorption performance of the bacterial cellulose. The bacterial cellulose hydrogel has good development prospect in the field of wound dressings, and provides a moist environment for wounds to promote the wounds to heal better. However, the three-dimensional nano-network structure of the bacterial cellulose hydrogel is lack of good waterproof and antibacterial properties, and external microorganisms and moisture can permeate into wounds through the nano-network structure. Meanwhile, the bacterial cellulose hydrogel dressing has a high water vapor transmission rate, and the water in the dressing is easy to lose in the using process. These problems have all restricted the application of bacterial cellulose hydrogel dressings.

Polyurethane is a generic name for polymers having a urethane group (-NHCOO-) in the main chain of the polymer structure. The soft and hard segments in the molecular structure of the gel are thermodynamic incompatible systems, have polarity difference, can cause microphase separation, and therefore have good biocompatibility and anticoagulation. A large number of animal experiments and acute and chronic toxicity experiments prove that the medical polyurethane material has good compatibility with human blood and tissue, no toxicity or distortion causing effect, no local anaphylactic reaction, good toughness, solvent resistance, hydrolysis resistance and antibacterial property, abrasion resistance, easy processing and forming and controllable performance, so the medical polyurethane material is considered to be one of the most valuable biomedical synthetic materials. 1. The dressing product prepared by adopting the polyurethane film can keep the wound surface moist, control the water vapor transmission rate and resist the invasion of microorganisms and external moisture. 2. The polyurethane foam material has good biocompatibility, hydrophilicity and softness, can absorb body fluid or blood, avoids forming effusion, has good softness and conformability, is beneficial to better adhering with tissues, reduces discomfort and pain, can load and release medicines according to needs due to a special porous structure, is not adhered with the tissues, and is easy to take off and replace. For example, the polyurethane foam dressing can be used for keeping a wound moist and allowing gas to pass through so as to promote the healing of the wound. However, in practical application, the biocompatibility, mechanical property and hydrophilic property of the polyurethane foam are to be enhanced, especially in the application aspects of human body repair materials, intelligent drug sustained-release materials and tissue engineering materials.

Thus, current skin wound dressing products are in need of further improvement.

Disclosure of Invention

An object of the present invention is to provide a bacterial cellulose-polyurethane composite material having a gradient structure; the invention also aims to provide a preparation method of the bacterial cellulose-polyurethane composite material with the gradient structure; the invention further aims to provide application of the bacterial cellulose-polyurethane composite material with the gradient structure in human body repair materials, intelligent drug sustained-release materials and tissue engineering materials.

The purpose of the invention is realized by the following technical scheme:

in one aspect, the invention provides a preparation method of a bacterial cellulose-polyurethane composite material, which comprises the following steps:

carrying out organic solvent exchange treatment on the bacterial cellulose microfiber to obtain a compound A and a compound B of the bacterial cellulose microfiber with different concentrations;

the composite A comprises 30-50 wt% of completely dehydrated bacterial cellulose microfiber and the balance of organic solvent, wherein the weight of the composite A is 100 wt%; the compound B comprises 15-30 wt% of partially dehydrated bacterial cellulose microfiber and the balance of organic solvent, wherein the weight part of the compound B is 100 wt%; wherein the partially dehydrated bacterial cellulose microfiber contains 5-10 wt% (based on the weight part of the compound B) of water;

mixing the compound A and the compound B according to the volume ratio of 1 (2-5), adding polymer polyol and diisocyanate compounds under the oil bath condition for addition polymerization reaction, and reacting to obtain a bacterial cellulose composite polyurethane foam prepolymer; curing the mixture to obtain a bacterial cellulose-polyurethane composite material;

wherein the weight ratio of the polymer polyol to the diisocyanate compound is 1: (0.1 to 0.2); the polymer polyol accounts for 20% -60% of the total weight of the compound A and the compound B.

According to the invention, the bacterial cellulose and polyurethane are creatively combined to prepare the composite material, the nano fiber microfiber of the bacterial cellulose is uniformly distributed in the polyurethane material to reinforce the polyurethane foam material, and the bacterial cellulose nanofiber and the polyurethane foam matrix are effectively combined in a chemical bonding manner through the interaction of the residual isocyanate group in the polyurethane reaction and the hydroxyl group on the surface of the bacterial cellulose nanofiber, so that the mechanical property of the composite material is obviously improved; the hydrophilic property and the water absorption capacity of the composite material are effectively improved by a large number of hydroxyl groups on the surface of the bacterial cellulose nanofiber; meanwhile, the good tissue affinity of the bacterial cellulose can improve the biocompatibility of the polyurethane material, the advantages of the two materials are exerted, and the obtained ideal skin wound dressing product has great application prospect in the biomedical field.

In the invention, the compound A is a mixture of the bacterial cellulose microfibril and the organic solvent after the bacterial cellulose microfibril is completely dehydrated, and the compound B is a mixture of the microfibril and the organic solvent after the bacterial cellulose microfibril is dehydrated to remove surface free water and still contains a small amount of bound water. The invention adopts a solvent exchange method to remove partial water molecules on the basis of not damaging the hydroxyl on the surface of the bacterial cellulose nanofiber; a small amount of bound water can react with isocyanate groups to form carbon dioxide (2 RNCO + H)₂O → RNHCONHR + CO₂×) having the function of pore-forming agent. In the preparation process, due to the fact that the cellulose microfiber has different water content and different specific gravity, the composite A and the composite B are automatically layered in the sedimentation process after being blended according to the volume ratio of 1 (2-5), and the amount of carbon dioxide gas for pore forming is different due to the difference of the water content, so that different pore size distributions are formed. Thus, prepared by the present inventionThe bacterial cellulose-polyurethane composite material is a gradient double-layer structure with different apertures, one layer is a macroporous layer (mainly containing more compounds B), the other layer is a microporous layer (mainly containing more compounds A), the bacterial cellulose-polyurethane composite material is an organic whole formed by the macroporous layer and the microporous layer, and the upper layer is the microporous layer which can prevent water and bacteria and control the water vapor permeability in the use process; the lower layer is a macroporous layer which can maintain moist microenvironment of the wound, control wound exudate and promote wound healing.

In the above preparation method, preferably, the method further comprises a step of purifying and homogenizing the bacterial cellulose obtained by fermenting the strain to obtain bacterial cellulose microfibrils; the strain comprises one or more of acetobacter xylinum, rhizobium, sarcina, pseudomonas, achromobacter, alcaligenes, aerobacter and azotobacter.

In the invention, the method for fermenting the strain is a conventional method in the field, the fermentation medium is a conventional medium for producing bacterial cellulose in the field, the fermentation time is generally 3-7 days, and the fermentation temperature is 30-37 ℃.

In the above preparation method, preferably, the method further comprises a step of purifying and homogenizing the bacterial cellulose obtained by fermenting the strain to obtain bacterial cellulose microfibrils; the method for purifying the bacterial cellulose comprises the following steps:

washing the bacterial cellulose in a sodium hydroxide aqueous solution with the mass percentage of 4-8% for 4-6 h at the temperature of 70-100 ℃, and repeatedly washing the bacterial cellulose to be neutral by using distilled water to remove mycoprotein on the bacterial cellulose and residual culture medium adhered to a cellulose membrane, thereby obtaining the purified bacterial cellulose.

In the above preparation method, preferably, the method of homogenizing the bacterial cellulose comprises:

homogenizing the purified bacterial cellulose for 5-10 min by adopting a high-speed dispersion machine at the rotating speed of 5000-25000 rpm to obtain the bacterial cellulose microfiber.

In the above preparation method, preferably, the bacterial cellulose microfiber has a length of 0.1 to 10 μm and a diameter of 50 to 100 nm. The bacterial cellulose microfiber is a fiber bundle formed by stranding a plurality of nanometer-scale bacterial cellulose fibers through intermolecular hydrogen bonds.

In the above preparation method, preferably, the organic solvent exchange treatment method comprises:

soaking the bacterial cellulose microfiber in absolute ethyl alcohol, and controlling the soaking time for 8-12h to obtain the completely dehydrated bacterial cellulose microfiber and controlling the soaking time for 3-6h to obtain the partially dehydrated bacterial cellulose microfiber;

soaking the completely dehydrated bacterial cellulose microfiber in an organic solvent for 48-72 hours to obtain a compound A;

and (3) soaking the partially dehydrated bacterial cellulose microfiber in an organic solvent for 12-48 h to obtain a compound B.

According to the invention, the control of the free water on the surface and the internal bound water of the bacterial cellulose microfiber is realized by soaking the bacterial cellulose microfiber in absolute ethyl alcohol, and with the increase of the soaking time of the absolute ethyl alcohol, the absolute ethyl alcohol can firstly separate out the free water on the surface of the bacterial cellulose microfiber and then separate out the bound water inside the bacterial cellulose microfiber (among nano fibers forming the microfiber). The compound A finally obtained is a mixture of the bacterial cellulose microfibrils and the organic solvent after the bacterial cellulose microfibrils are completely dehydrated, and the compound B is a mixture of the microfibrils and the organic solvent, wherein free water on the surfaces of the microfibrils is removed, and a small amount of bound water is still contained.

In the above preparation method, preferably, the organic solvent includes one or more of ethyl glycol acetate, ethyl acetate, butyrolactone, acetic acid and acetone.

The organic solvent adopted by the invention can reduce the interaction between the nano-scale cellulose fiber in the bacterial cellulose and water molecules, avoid the existence of free water, improve the reaction efficiency in the production process of polyurethane foam, and simultaneously strengthen the interface action between the nano-scale cellulose fiber of the bacterial cellulose and polyurethane.

In the above production process, preferably, the addition polymerization is carried out under the conditions of: and (3) carrying out oil bath at a constant temperature of 70-80 ℃ for 60-90 min.

In the above preparation method, preferably, the polymer polyol includes one or more of polyethylene glycol, polypropylene oxide, propylene glycol and diethylene glycol.

In the above preparation method, preferably, the method for curing the bacterial cellulose composite polyurethane foam prepolymer comprises:

adding a curing assistant into the bacterial cellulose composite polyurethane foam prepolymer, uniformly stirring, then adding a diisocyanate compound and water, uniformly stirring to obtain a mixture, and then curing to obtain the bacterial cellulose-polyurethane composite material.

In the preparation method, preferably, the amount of the curing assistant is 0.5-2.6 wt% of the amount of the bacterial cellulose composite polyurethane foam prepolymer.

In the above preparation method, preferably, the ratio of the diisocyanate compound to water is (20-40): (2-5).

In the preparation method, preferably, during curing, the amount of the diisocyanate compound is 20-50% of the amount of the polymer polyol.

In the above preparation method, preferably, the diisocyanate compound includes one or more of toluene diisocyanate, diphenylmethane diisocyanate and isophorone diisocyanate.

In the invention, polymer polyol and diisocyanate are respectively used for acting on the soft segment structure and the hard segment structure of the polyurethane material, and the generated polyether polyurethane has excellent mechanical property and good biocompatibility.

In the above preparation method, preferably, the curing assistant comprises a catalyst, a pore-forming agent and a stabilizer;

the catalyst comprises one or more of triethylene diamine, dimethyl ethanolamine, dibutyltin dilaurate and stannous octoate;

the cell opener comprises one or more of a combination of cell opener silicone oil, silicone oil 6070 and polybutadiene diol;

the stabilizer comprises one or more of organic silicon surfactant, sodium cocoamphoacetate, sodium lauroamphoacetate and disodium lauroamphodiacetate.

In the preparation method, preferably, the amount of the catalyst is 0.3-1.5 wt% of the amount of the bacterial cellulose composite polyurethane foam prepolymer; the using amount of the pore-forming agent is 0.1-1 wt% of that of the bacterial cellulose composite polyurethane foam prepolymer; the dosage of the stabilizer is 0.1-0.5 wt% of the dosage of the bacterial cellulose composite polyurethane foam prepolymer.

The curing auxiliary agent is beneficial to the conversion of the polyurethane foam material from liquid state to solid state, and simultaneously generates a urethane bond along with the interaction of the residual isocyanate group in polyurethane and the hydroxyl group on the surface of the bacterial cellulose nanofiber, so that the bacterial cellulose nanofiber and the polyurethane foam material are effectively combined in a chemical bonding mode.

In the preparation method, preferably, the curing is to place the uniformly mixed and stirred mixture in a mold and to stand the mold for 2 to 7 days at room temperature.

On the other hand, the invention also provides a bacterial cellulose-polyurethane composite material which comprises at least two layers of structures, namely a macroporous layer and a microporous layer, wherein the aperture of the macroporous layer is 100-500 mu m, the porosity is 70-90%, and the thickness is 0.5-1 cm; the aperture of the microporous layer is 10-80 mu m, and the porosity is 60% -80%; the thickness is 0.1-0.3 cm.

The bacterial cellulose-polyurethane composite material is prepared by the preparation method.

In the bacterial cellulose-polyurethane composite material, the mass ratio of the bacterial cellulose microfibers in the composite material is 20-40 wt%, and hydroxyl groups on the surfaces of the nanofibers and residual isocyanate groups in polyurethane are chemically bonded.

The bacterial cellulose-polyurethane composite material prepared by the invention has a gradient double-layer structure with different pore diameters, wherein one layer is a macroporous layer, and the other layer is a microporous layer. The bacterial cellulose-polyurethane composite material is an organic whole body formed by a macroporous layer and a microporous layer, and the upper layer is the microporous layer which can prevent water and bacteria and control the water vapor transmission rate in the use process; the lower layer is a macroporous layer which can maintain moist microenvironment of the wound, control wound exudate and promote wound healing.

On the other hand, the invention also provides application of the bacterial cellulose-polyurethane composite material in human body repair materials, intelligent drug sustained-release materials and tissue engineering materials.

The invention has the beneficial effects that:

(1) according to the invention, the bacterial cellulose nanofiber microfiber is compounded with the polyurethane foam material, so that the mechanical property of the composite material is obviously improved; the large amount of hydroxyl on the surface of the bacterial cellulose nanofiber effectively enhances the hydrophilic property and the water absorption capacity of the composite material; meanwhile, the good tissue affinity of the bacterial cellulose can improve the biocompatibility of the polyurethane material;

(2) the method effectively combines the bacterial cellulose nanofibers and the polyurethane foam matrix in a chemical bonding mode through the interaction of residual isocyanate groups in the polyurethane reaction and hydroxyl groups on the surface of the bacterial cellulose nanofibers;

(3) the preparation method disclosed by the invention is simple in preparation process, low in cost and free of pollution, and the obtained environment-friendly degradable bacterial cellulose composite polyurethane foam material is obtained. The material has good biocompatibility, mechanical property, hydrophilic/water-holding property and water absorption capacity, and has great application prospect in biomedical fields such as human body repair materials, intelligent drug sustained-release materials, tissue engineering materials and the like.

Detailed Description

The technical solutions of the present invention will be described in detail below in order to clearly understand the technical features, objects, and advantages of the present invention, but the present invention is not limited to the practical scope of the present invention.

The experimental procedures used in the following examples are all conventional procedures unless otherwise specified.

Materials, reagents and the like used in the following examples are commercially available unless otherwise specified.

Example 1

The embodiment provides a preparation method of a bacterial cellulose-polyurethane composite material, which comprises the following steps:

step one, soaking bacterial cellulose obtained by fermenting and culturing acetobacter xylinum in a NaOH aqueous solution with the mass percentage of 4%, heating for 6 hours at the temperature of 100 ℃, and repeatedly washing with distilled water until the bacterial cellulose is neutral; and homogenizing the purified bacterial cellulose sample for 10min by adopting a high-speed dispersion machine at the rotating speed of 25000rpm to obtain the bacterial cellulose microfiber with the length of 0.1 mu m and the diameter of 50 nm.

And secondly, soaking the homogenized bacterial cellulose microfiber in absolute ethyl alcohol for 8 hours to ensure that the bacterial cellulose microfiber is completely dehydrated, and then soaking the dehydrated bacterial cellulose microfiber in an organic solvent ethyl glycol acetate for 48 hours to prepare a compound A, wherein the compound A comprises 30wt% of bacterial cellulose microfiber and the balance of organic solvent (the balance of organic solvent comprises residual absolute ethyl alcohol and ethyl glycol acetate) by weight of 100 wt%.

Soaking the homogenized bacterial cellulose microfiber in absolute ethyl alcohol for 3 hours to remove most of water in the bacterial cellulose microfiber, and then soaking the partially dehydrated bacterial cellulose microfiber in organic solvents acetic acid and acetone for 12 hours to prepare a compound B, wherein the compound B comprises 15wt% of the partially dehydrated bacterial cellulose microfiber and the balance of organic solvents (the balance of the organic solvents comprises residual absolute ethyl alcohol, acetic acid and acetone) in parts by weight of 100 wt%; wherein the partially dehydrated bacterial cellulose microfibrils contain 5wt% water.

And step three, mixing the compound A and the compound B according to the volume ratio of 1:2, adding polymer polyol under the condition of a constant-temperature oil bath at 70 ℃, adding a small amount of diisocyanate compounds for addition polymerization, stirring for 60min, and reacting to obtain the bacterial cellulose composite polyurethane foam prepolymer. Wherein the amount of the polymer polyol added is 20% of the total mass of the composite A and the composite B after mixing.

And step four, adding a curing auxiliary agent (catalyst, a pore-forming agent and a stabilizing agent) into the bacterial cellulose composite polyurethane foam prepolymer, uniformly stirring, adding a diisocyanate compound and water, stirring at a high speed, placing in a mold, standing and curing at normal temperature for 2 days to obtain the bacterial cellulose-polyurethane composite material.

The dosage is as follows: the added polymer polyol is polyethylene glycol based on 100 parts by weight, the added diisocyanate compound is toluene diisocyanate, the total amount is 60 parts by weight, wherein a small amount of diisocyanate compound is added firstly, the weight of the diisocyanate compound accounts for 20% of the total weight of the substance, and the weight of the added water is 5 parts by weight.

The added curing auxiliary agent comprises a catalyst, a pore-forming agent and a stabilizing agent; wherein the catalyst is triethylene diamine, and the dosage of the catalyst is 0.3wt% of the dosage of the bacterial cellulose composite polyurethane foam prepolymer; the cell-opening agent is cell-opening silicone oil, and the using amount of the cell-opening silicone oil is 1wt% of the using amount of the bacterial cellulose composite polyurethane foam prepolymer; the stabilizer is organic silicon surfactant, and the dosage of the stabilizer is 0.5wt% of the dosage of the bacterial cellulose composite polyurethane foam prepolymer.

The bacterial cellulose-polyurethane composite material has a gradient double-layer structure with different pore diameters, wherein one layer is a macroporous layer, the pore diameter of the macroporous layer is 100 mu m, the porosity is 70%, and the thickness is 0.5 cm; the other layer was a microporous layer with a pore size of 10 μm, a porosity of 60% and a thickness of 0.1 cm. The bacterial cellulose-polyurethane composite material is an organic whole body formed by a macroporous layer and a microporous layer, and the upper layer is the microporous layer which can prevent water and bacteria and control the water vapor transmission rate in the use process; the lower layer is a macroporous layer which can maintain moist microenvironment of the wound, control wound exudate and promote wound healing.

Example 2

The embodiment provides a preparation method of a bacterial cellulose-polyurethane composite material, which comprises the following steps:

step one, soaking bacterial cellulose obtained by fermenting and culturing rhizobium and sarcina in a 5% NaOH aqueous solution by mass percentage, heating for 5 hours at the temperature of 90 ℃, and repeatedly washing with distilled water until the bacterial cellulose is neutral; and homogenizing the purified bacterial cellulose sample for 5min by adopting a high-speed dispersion machine at the rotating speed of 20000rpm to obtain the bacterial cellulose microfiber with the length of 2 mu m and the diameter of 60 nm.

And step two, soaking the homogenized bacterial cellulose microfiber in absolute ethyl alcohol for 10 hours to ensure that the bacterial cellulose microfiber is completely dehydrated, and then soaking the dehydrated bacterial cellulose microfiber in organic solvent ethyl acetate for 36 hours to prepare a compound A, wherein the compound A comprises 40wt% of bacterial cellulose microfiber and the balance of organic solvent (the balance of organic solvent comprises residual absolute ethyl alcohol and residual ethyl acetate) by weight of 100 wt%.

Soaking the homogenized bacterial cellulose microfiber in absolute ethyl alcohol for 4 hours to remove most of water in the bacterial cellulose microfiber, and then soaking the partially dehydrated bacterial cellulose microfiber in organic solvent acetone for 48 hours to prepare a compound B, wherein the compound B comprises 20wt% of partially dehydrated bacterial cellulose microfiber and the balance of organic solvent (the balance of organic solvent comprises residual absolute ethyl alcohol and acetone) by taking the weight part as 100 wt%; wherein the partially dehydrated bacterial cellulose microfibrils contain 5wt% water.

And step three, mixing the compound A and the compound B according to the volume ratio of 1:3, adding polymer polyol under the condition of a constant-temperature oil bath at 70 ℃, adding a small amount of diisocyanate compounds for addition polymerization, stirring for 70min, and reacting to obtain the bacterial cellulose composite polyurethane foam prepolymer. Wherein the amount of the polymer polyol added is 30% of the total mass of the composite A and the composite B after mixing.

And step four, adding a curing auxiliary agent (catalyst, a pore-forming agent and a stabilizing agent) into the bacterial cellulose composite polyurethane foam prepolymer, uniformly stirring, adding a diisocyanate compound and water, stirring at a high speed, placing in a mold, standing and curing at normal temperature for 3 days to obtain the bacterial cellulose-polyurethane composite material.

The dosage is as follows: the polymer polyol is polypropylene oxide based on 100 parts by weight, the diisocyanate compound is diphenylmethane diisocyanate based on 60 parts by weight, wherein a small amount of diisocyanate compound is added to account for 20% of the total weight of the material, and the water is added in an amount of 4 parts by weight.

The added curing auxiliary agent comprises a catalyst, a pore-forming agent and a stabilizing agent; wherein the catalyst is dimethylethanolamine, and the using amount of the dimethylethanolamine is 0.7 wt% of the using amount of the bacterial cellulose composite polyurethane foam prepolymer; the cell opening agent is silicone oil 6070, and the using amount of the cell opening agent is 0.8 wt% of the using amount of the bacterial cellulose composite polyurethane foam prepolymer; the stabilizer is sodium cocoyl amphoacetate, and the dosage of the stabilizer is 0.4wt% of that of the bacterial cellulose composite polyurethane foam prepolymer.

The bacterial cellulose-polyurethane composite material has a gradient double-layer structure with different pore diameters, wherein one layer is a macroporous layer, the pore diameter of the macroporous layer is 200 mu m, the porosity is 70 percent, and the thickness is 0.7 cm; the other layer was a microporous layer with a pore size of 20 μm, a porosity of 60% and a thickness of 0.1 cm. The bacterial cellulose-polyurethane composite material is an organic whole body formed by a macroporous layer and a microporous layer, and the upper layer is the microporous layer which can prevent water and bacteria and control the water vapor transmission rate in the use process; the lower layer is a macroporous layer which can maintain moist microenvironment of the wound, control wound exudate and promote wound healing.

Example 3

The embodiment provides a preparation method of a bacterial cellulose-polyurethane composite material, which comprises the following steps:

step one, soaking bacterial cellulose obtained by fermenting and culturing pseudomonas and achromobacter in 6 mass percent of NaOH aqueous solution, heating for 4 hours at the temperature of 80 ℃, and repeatedly washing with distilled water until the bacterial cellulose is neutral; and homogenizing the purified bacterial cellulose sample for 6min by adopting a high-speed dispersion machine at the rotating speed of 25000rpm to obtain the bacterial cellulose microfiber with the length of 4 mu m and the diameter of 70 nm.

And secondly, soaking the homogenized bacterial cellulose microfiber in absolute ethyl alcohol for 9 hours to ensure that the bacterial cellulose microfiber is completely dehydrated, and then soaking the dehydrated bacterial cellulose microfiber in organic solvent butyrolactone for 72 hours to prepare a compound A, wherein the compound A comprises 50wt% of bacterial cellulose microfiber and the balance of organic solvent (the balance of organic solvent comprises residual absolute ethyl alcohol and butyrolactone) by weight of 100 wt%.

Soaking the homogenized bacterial cellulose microfiber in absolute ethyl alcohol for 5 hours to remove most of water in the bacterial cellulose microfiber, and then soaking a part of dehydrated bacterial cellulose microfiber in an organic solvent ethyl glycol acetate for 12 hours to prepare a compound B, wherein the compound B comprises 30wt% of the part of dehydrated bacterial cellulose microfiber and the balance of organic solvent (the balance of the organic solvent comprises residual absolute ethyl alcohol and ethyl glycol acetate) by taking the weight part as 100 wt%; wherein the partially dehydrated bacterial cellulose microfibrils contain 10wt% water.

And step three, mixing the compound A and the compound B according to the volume ratio of 1:4, adding polymer polyol under the condition of a constant-temperature oil bath at 70 ℃, adding a small amount of diisocyanate compounds for addition polymerization, stirring for 60min, and reacting to obtain the bacterial cellulose composite polyurethane foam prepolymer. Wherein the amount of the polymer polyol added is 40% of the total mass of the composite A and the composite B after mixing.

And step four, adding a curing auxiliary agent (catalyst, a pore-forming agent and a stabilizing agent) into the bacterial cellulose composite polyurethane foam prepolymer, uniformly stirring, adding a diisocyanate compound and water, stirring at a high speed, placing in a mold, standing and curing at normal temperature for 4 days to obtain the bacterial cellulose-polyurethane composite material.

The dosage is as follows: the added polymer polyol is propylene glycol and diethylene glycol (1: 1) in total 100 parts by weight, the added diisocyanate compound is isophorone diisocyanate in total 50 parts by weight, a small amount of diisocyanate compound is added to account for 20% of the total weight of the material, and the added water is added in 3 parts by weight.

The added curing auxiliary agent comprises a catalyst, a pore-forming agent and a stabilizing agent; wherein the catalyst is dibutyltin dilaurate, and the using amount of the catalyst is 0.9 wt% of that of the bacterial cellulose composite polyurethane foam prepolymer; the cell opening agent is polybutadiene glycol, and the using amount of the cell opening agent is 0.5wt% of that of the bacterial cellulose composite polyurethane foam prepolymer; the stabilizer is 0.3wt% of the usage of the lauroyl amphoacetate in the bacterial cellulose composite polyurethane foam prepolymer.

The bacterial cellulose-polyurethane composite material has a gradient double-layer structure with different apertures, wherein one layer is a macroporous layer, the aperture of the macropore is 300 mu m, the porosity is 80%, and the thickness is 0.8 cm; the other layer was a microporous layer with a pore size of 40 μm, a porosity of 70% and a thickness of 0.2 cm. The bacterial cellulose-polyurethane composite material is an organic whole body formed by a macroporous layer and a microporous layer, and the upper layer is the microporous layer which can prevent water and bacteria and control the water vapor transmission rate in the use process; the lower layer is a macroporous layer which can maintain moist microenvironment of the wound, control wound exudate and promote wound healing.

Example 4

The embodiment provides a preparation method of a bacterial cellulose-polyurethane composite material, which comprises the following steps:

step one, soaking bacterial cellulose obtained by mixed fermentation culture of Alcaligenes, Aerobacter and azotobacter in 7% NaOH aqueous solution by mass percentage, heating for 4h at 70 ℃, and repeatedly washing with distilled water to neutrality; and homogenizing the purified bacterial cellulose sample for 8min by adopting a high-speed dispersion machine at the rotating speed of 15000rpm to obtain the bacterial cellulose microfiber with the length of 6 mu m and the diameter of 80 nm.

And secondly, soaking the homogenized bacterial cellulose microfiber in absolute ethyl alcohol for 10 hours to ensure that the bacterial cellulose microfiber is completely dehydrated, and then soaking the dehydrated bacterial cellulose microfiber in organic solvents acetic acid and acetone for 36 hours to prepare a compound A, wherein the compound A comprises 30wt% of bacterial cellulose microfiber and the balance of organic solvents (the balance of organic solvents comprises residual absolute ethyl alcohol, acetic acid and acetone) by weight of 100 wt%.

Soaking the homogenized bacterial cellulose microfiber in absolute ethyl alcohol for 6 hours to remove most of water in the bacterial cellulose microfiber, and then soaking the partially dehydrated bacterial cellulose microfiber in organic solvent acetone for 12 hours to prepare a compound B, wherein the compound B comprises 23wt% of partially dehydrated bacterial cellulose microfiber and the balance of organic solvent (the balance of organic solvent comprises residual absolute ethyl alcohol and acetone) by taking the weight part as 100 wt%; wherein the partially dehydrated bacterial cellulose microfibrils contain 8wt% water.

And step three, mixing the compound A and the compound B according to the volume ratio of 1:5, adding polymer polyol under the condition of a constant-temperature oil bath at the temperature of 80 ℃, adding a small amount of diisocyanate compounds for addition polymerization, stirring for 70min, and reacting to obtain the bacterial cellulose composite polyurethane foam prepolymer. Wherein the amount of the polymer polyol added is 50% of the total mass of the composite A and the composite B after mixing.

And step four, adding a curing auxiliary agent (catalyst, a pore-forming agent and a stabilizing agent) into the bacterial cellulose composite polyurethane foam prepolymer, uniformly stirring, adding a diisocyanate compound and water, stirring at a high speed, placing in a mold, standing and curing at normal temperature for 5 days to obtain the bacterial cellulose-polyurethane composite material.

The dosage is as follows: the added polymer polyol is polyethylene glycol and polypropylene oxide (1: 1), the total amount of the added diisocyanate compounds is 100 parts by weight, the total amount of the added diisocyanate compounds is toluene diisocyanate and diphenylmethane diisocyanate (1: 1) is 50 parts by weight, wherein a small amount of the diisocyanate compounds accounting for 10 percent of the total weight of the material is added firstly, and the weight of the added water is 2 parts by weight.

The added curing auxiliary agent comprises a catalyst, a pore-forming agent and a stabilizing agent; wherein the dosage of the catalyst is 1.0wt% of the dosage of the bacterial cellulose composite polyurethane foam prepolymer, namely triethylene diamine and stannous octoate (1: 1); the cell-opening agent is cell-opening silicone oil and silicone oil 6070 (1: 1), and the dosage of the cell-opening agent is 0.5wt% of the dosage of the bacterial cellulose composite polyurethane foam prepolymer; the stabilizer is disodium lauroamphodiacetate, and the using amount of the stabilizer is 0.2wt% of that of the bacterial cellulose composite polyurethane foam prepolymer.

The bacterial cellulose-polyurethane composite material has a gradient double-layer structure with different pore diameters, wherein one layer is a macroporous layer, the pore diameter of the macroporous layer is 300 mu m, the porosity is 80%, and the thickness is 0.6 cm; the other layer was a microporous layer with a pore size of 50 μm, a porosity of 70% and a thickness of 0.2 cm. The bacterial cellulose-polyurethane composite material is an organic whole body formed by a macroporous layer and a microporous layer, and the upper layer is the microporous layer which can prevent water and bacteria and control the water vapor transmission rate in the use process; the lower layer is a macroporous layer which can maintain moist microenvironment of the wound, control wound exudate and promote wound healing.

Example 5

The embodiment provides a preparation method of a bacterial cellulose-polyurethane composite material, which comprises the following steps:

step one, soaking bacterial cellulose obtained by fermentation culture of acetobacter xylinum and pseudomonas in 6 mass percent of NaOH aqueous solution, heating for 5 hours at the temperature of 100 ℃, and repeatedly washing with distilled water until the bacterial cellulose is neutral; and homogenizing the purified bacterial cellulose sample for 9 min by adopting a high-speed dispersion machine at the rotating speed of 10000 rpm to obtain the bacterial cellulose microfiber with the length of 8 mu m and the diameter of 90 nm.

And secondly, soaking the homogenized bacterial cellulose microfiber in absolute ethyl alcohol for 11 hours to ensure that the bacterial cellulose microfiber is completely dehydrated, and then soaking the dehydrated bacterial cellulose microfiber in organic solvents ethyl glycol acetate and ethyl acetate for 48 hours to prepare a compound A, wherein the compound A comprises 40wt% of bacterial cellulose microfiber and the balance of organic solvents (the balance of organic solvents comprises residual absolute ethyl alcohol, ethyl glycol acetate and ethyl acetate) by weight of 100 wt%.

Soaking the homogenized bacterial cellulose microfiber in absolute ethyl alcohol for 7 hours to remove most of water in the bacterial cellulose microfiber, and then soaking the partially dehydrated bacterial cellulose microfiber in an organic solvent ethyl glycol acetate for 36 hours to prepare a compound B, wherein the compound B comprises 26wt% of partially dehydrated bacterial cellulose microfiber and the balance of organic solvent (the balance of organic solvent comprises residual absolute ethyl alcohol and ethyl glycol acetate) by taking the weight part as 100 wt%; wherein the partially dehydrated bacterial cellulose microfibrils contain 6wt% water.

And step three, mixing the compound A and the compound B according to the volume ratio of 1:3, adding polymer polyol under the condition of a constant-temperature oil bath at the temperature of 80 ℃, adding a small amount of diisocyanate compounds for addition polymerization, stirring for 80min, and reacting to obtain the bacterial cellulose composite polyurethane foam prepolymer. Wherein the amount of the polymer polyol added is 60% of the total mass of the composite A and the composite B after mixing.

And step four, adding a curing auxiliary agent (catalyst, a pore-forming agent and a stabilizing agent) into the bacterial cellulose composite polyurethane foam prepolymer, uniformly stirring, adding a diisocyanate compound and water, stirring at a high speed, placing in a mold, standing and curing at normal temperature for 6 days to obtain the bacterial cellulose-polyurethane composite material.

The dosage is as follows: the polymer polyol is polyethylene glycol and propylene glycol (2: 1) by 100 parts by weight, the diisocyanate compound is diphenylmethane diisocyanate and isophorone diisocyanate (1: 1) by 40 parts by weight, wherein a small amount of the diisocyanate compound accounting for 10% of the total weight of the material is added, and the water is added by 3 parts by weight.

The added curing auxiliary agent comprises a catalyst, a pore-forming agent and a stabilizing agent; wherein the dosage of the catalyst is 1.2 wt% of the dosage of the bacterial cellulose composite polyurethane foam prepolymer, wherein the dosage of the catalyst is 1:1 of dimethylethanolamine and stannous octoate; the cell opener comprises cell opening silicone oil and polybutadiene diol (2: 1), and the using amount of the cell opening agent is 0.3wt% of that of the bacterial cellulose composite polyurethane foam prepolymer; the stabilizer is organosilicon surfactant and sodium cocoyl amphoacetate (1: 1), and the dosage of the stabilizer is 0.1wt% of the dosage of the bacterial cellulose composite polyurethane foam prepolymer.

The bacterial cellulose-polyurethane composite material has a gradient double-layer structure with different pore diameters, wherein one layer is a macroporous layer, the pore diameter of the macroporous layer is 400 mu m, the porosity is 90%, and the thickness is 0.9 cm; the other layer was a microporous layer with a pore size of 60 μm, a porosity of 80% and a thickness of 0.3 cm. The bacterial cellulose-polyurethane composite material is an organic whole body formed by a macroporous layer and a microporous layer, and the upper layer is the microporous layer which can prevent water and bacteria and control the water vapor transmission rate in the use process; the lower layer is a macroporous layer which can maintain moist microenvironment of the wound, control wound exudate and promote wound healing.

Example 6

The embodiment provides a preparation method of a bacterial cellulose-polyurethane composite material, which comprises the following steps:

step one, soaking bacterial cellulose obtained by fermenting and culturing acetobacter xylinum in 8 mass percent of NaOH aqueous solution, heating for 6 hours at the temperature of 80 ℃, and repeatedly washing with distilled water until the bacterial cellulose is neutral; and homogenizing the purified bacterial cellulose sample for 10min by adopting a high-speed dispersion machine at the rotating speed of 5000rpm to obtain the bacterial cellulose microfiber with the length of 10 mu m and the diameter of 100 nm.

And secondly, soaking the homogenized bacterial cellulose microfiber in absolute ethyl alcohol for 12 hours to ensure that the bacterial cellulose microfiber is completely dehydrated, and then soaking the dehydrated bacterial cellulose microfiber in organic solvents of ethyl acetate and acetone for 72 hours to prepare a compound A, wherein the compound A comprises 50wt% of bacterial cellulose microfiber and the balance of organic solvents (the balance of organic solvents comprises residual absolute ethyl alcohol and residual ethyl acetate) by weight of 100 wt%.

Soaking the homogenized bacterial cellulose microfiber in absolute ethyl alcohol for 6 hours to remove most of water in the bacterial cellulose microfiber, and then soaking the partially dehydrated bacterial cellulose microfiber in an organic solvent ethyl acetate for 48 hours to prepare a compound B, wherein the compound B comprises 30wt% of the partially dehydrated bacterial cellulose microfiber and the balance of organic solvent (the balance of the organic solvent comprises residual absolute ethyl alcohol and residual ethyl acetate) by taking the weight part as 100 wt%; wherein the partially dehydrated bacterial cellulose microfibrils contain 10wt% water.

And step three, mixing the compound A and the compound B according to the volume ratio of 1:2, adding polymer polyol under the condition of a constant-temperature oil bath at the temperature of 80 ℃, adding a small amount of diisocyanate compounds for addition polymerization, stirring for 90min, and reacting to obtain the bacterial cellulose composite polyurethane foam prepolymer. Wherein the amount of the polymer polyol added is 40% of the total mass of the composite A and the composite B after mixing.

And step four, adding a curing auxiliary agent (catalyst, a pore-forming agent and a stabilizing agent) into the bacterial cellulose composite polyurethane foam prepolymer, uniformly stirring, adding a diisocyanate compound and water, stirring at a high speed, placing in a mold, standing at normal temperature and curing for 7 days to obtain the bacterial cellulose-polyurethane composite material.

The dosage is as follows: the added polymer polyol is polyethylene glycol based on 100 parts by weight, the added diisocyanate compound is toluene diisocyanate and isophorone diisocyanate (4: 1) with the total weight of 40 parts by weight, wherein a small amount of diisocyanate compound is added firstly and accounts for 10% of the total weight of the material; water was added in an amount of 4 parts by weight.

The added curing auxiliary agent comprises a catalyst, a pore-forming agent and a stabilizing agent; wherein the dosage of the catalyst is 1.5wt% of the dosage of the bacterial cellulose composite polyurethane foam prepolymer, namely dibutyltin dilaurate and stannous octoate (1: 1); the cell-opening agent is 0.1wt% of cell-opening silicone oil, silicone oil 6070 and polybutadiene diol (2: 1: 1); the stabilizer is sodium cocoyl amphoacetate, sodium lauroamphoacetate and disodium lauroamphodiacetate (1: 1: 1), and the dosage of the stabilizer is 0.1wt% of the dosage of the bacterial cellulose composite polyurethane foam prepolymer.

The bacterial cellulose-polyurethane composite material has a gradient double-layer structure with different pore diameters, wherein one layer is a macroporous layer, the pore diameter of the macroporous layer is 500 mu m, the porosity is 90%, and the thickness is 1 cm; the other layer was a microporous layer with a pore size of 80 μm, a porosity of 80% and a thickness of 0.3 cm. The bacterial cellulose-polyurethane composite material is an organic whole body formed by a macroporous layer and a microporous layer, and the upper layer is the microporous layer which can prevent water and bacteria and control the water vapor transmission rate in the use process; the lower layer is a macroporous layer which can maintain moist microenvironment of the wound, control wound exudate and promote wound healing.

Performance test experiments:

the bacterial cellulose-polyurethane composite material prepared in the examples was subjected to the following performance tests:

the experiment of the water vapor transmission rate of the ventilated membrane dressing comprises the following steps: following YY/T0471.2-2004, part 2 of the contact wound dressing test procedure: the water vapor transmission rate of the bacterial cellulose-polyurethane composite material is tested by breathable film dressing water vapor transmission rate, and the water vapor transmission rate (MVTR) is 1600 grams per square meter per 24 metersHour (g.m)^-2•24h^-1)。

Biocompatibility experiment: with reference to the biological evaluation of GB/T16886 medical instruments, the bacterial cellulose-polyurethane composite material is respectively evaluated for cytotoxicity, delayed contact sensitization of guinea pigs, skin irritation and the like.

Evaluation of biocompatibility: intracellular toxicity test according to GB/T16886-5, part 5 of the biological evaluation of medical devices: in vitro cytotoxicity test "; guinea pig delayed contact sensitization test according to GB/T16886-10, part 10 of the biological evaluation of medical devices: stimulation and delayed type hypersensitivity tests were performed using the Maxinusson and Kligman methods for the maximum tests. Skin irritation test according to GB/T16886-10, part 10 of the biological evaluation of medical devices: stimulation and delayed type hypersensitivity tests.

The results show that: the bacterial cellulose-polyurethane composite material prepared by the embodiment of the invention has cytotoxicity less than 2 grade, no skin sensitization reaction, no skin irritation reaction and good biological safety.