阅读说明：本技术 一种复合气凝胶敷料及其制备方法 (Composite aerogel dressing and preparation method thereof ) 是由 拜永孝 周洪宇 党锡江 张桂兰 于 2021-08-30 设计创作，主要内容包括：本发明公开了一种复合气凝胶敷料及其制备方法。本发明的一种复合气凝胶敷料,该气凝胶敷料由下述质量百分比的原料组成：聚乙烯醇4％～10％、水溶性壳聚糖5％～50％、氧化石墨烯0.1％～3％,余量为去离子水。一种如上述的复合气凝胶敷料的制备方法,按照上述质量百分比配置混合溶液,将混合溶液先冷冻再解冻多次得水凝胶,将得到的水凝胶冷冻干燥得复合气凝胶敷料。本发明的复合气凝胶敷料具有止血、抗菌和促进伤口愈合的功能,同时成本低、环保、制备工艺简单、对设备没有特殊要求和较好的生物相容性,在医用伤口敷料方面具有很大的潜能。(The invention discloses a composite aerogel dressing and a preparation method thereof. The invention relates to a composite aerogel dressing which is prepared from the following raw materials in percentage by mass: 4-10% of polyvinyl alcohol, 5-50% of water-soluble chitosan, 0.1-3% of graphene oxide and the balance of deionized water. The preparation method of the composite aerogel dressing comprises the steps of preparing a mixed solution according to the mass percentage, freezing the mixed solution, then unfreezing the mixed solution for multiple times to obtain hydrogel, and freezing and drying the obtained hydrogel to obtain the composite aerogel dressing. The composite aerogel dressing has the functions of stopping bleeding, resisting bacteria and promoting wound healing, and has the advantages of low cost, environmental protection, simple preparation process, no special requirement on equipment and better biocompatibility, and great potential in the aspect of medical wound dressings.)

1. A composite aerogel dressing, comprising: the aerogel dressing consists of the following raw materials in percentage by mass: 4-10% of polyvinyl alcohol, 5-50% of water-soluble chitosan, 0.1-3% of graphene oxide and the balance of deionized water.

2. A composite aerogel dressing as claimed in claim 1, wherein: the polymerization degree of the polyvinyl alcohol is 1700-2600, and the alcoholysis degree is 90-99%.

3. A composite aerogel dressing as claimed in claim 2, wherein: the water-soluble chitosan is water-soluble carboxymethyl chitosan.

4. A method of making a composite aerogel dressing as claimed in any of claims 1 to 3, wherein: preparing a mixed solution according to the mass percentage, freezing the mixed solution firstly, then unfreezing for many times to obtain hydrogel, and freeze-drying the obtained hydrogel to obtain the composite aerogel dressing.

5. A method of making a composite aerogel dressing as claimed in claim 4, wherein: the specific preparation steps of the composite aerogel dressing are as follows:

(1) preparing a polyvinyl alcohol aqueous solution with the mass fraction of 4-10%, adding 5-50% of water-soluble chitosan and 0.1-3% of graphene oxide into the polyvinyl alcohol aqueous solution, uniformly stirring at room temperature, and standing for defoaming;

(2) pouring the solution obtained in the step (1) into a plastic culture dish, freezing for 22-24 h at-18 to-20 ℃, unfreezing for 2-4 h at room temperature, and circulating the process for 1-3 times to obtain hydrogel;

(3) and (3) putting the hydrogel obtained in the step (2) into a freeze dryer for freeze drying for 2-4 days to obtain the composite aerogel dressing.

Technical Field

The invention relates to the technical field of medical materials, in particular to a composite aerogel dressing and a preparation method thereof.

Background

Traditional medical dressings, such as medical cotton balls, gauze or bandages and the like, can absorb wound exudates to different degrees and have a certain protection effect on wounds, but the wound dressings can only be temporary covering materials, the traditional medical wound dressings are usually dry and cannot provide a moist healing environment for the wounds, and when the dressings are soaked, exogenous infection of the wounds is very easily caused. In addition, the traditional wound dressing is easy to be bonded with a wound during dressing change, secondary damage is caused, and the healing process of the wound surface is delayed. Compared with the traditional wound dressing, the novel medical dressing can better cover the surface of a wound, can also provide a proper healing environment, and accelerates the re-functionalization and repair process of wound tissues. The ideal new wound dressing should generally have the following functions: can absorb excessive tissue exudate and simultaneously avoid excessive loss of moisture and body fluid; the wound dressing is moisture permeable and air permeable, and can maintain a moist environment for the wound; can resist the invasion of external microorganisms and control the infection of wounds; the dressing change is easy, and the secondary damage of skin wounds can not be caused. According to the source of raw materials, the novel medical dressing can be generally divided into synthetic polymer materials and natural polymer materials, including sponges, gels, foams, films and the like. But there are certain drawbacks in new medical dressings such as foams, sponges and films. The foam dressing can become white locally after absorbing seepage, and error can be caused. The adhesive is high, and if the adhesive is removed in a short time, the adhesive of the dressing can cause skin damage when the adhesive is still high; sponge dressings may require the use of two layers of dressing or tape for fixation; when the amount of the seepage is large, if the seepage is not replaced in time, the skin around the wound can be soaked, the seepage is not easy to remove during replacement, and secondary damage can be caused to the wound; thin film dressings cannot be used when the surrounding skin is fragile or infects a wound.

Disclosure of Invention

The invention aims to provide a composite aerogel dressing with the functions of stopping bleeding, resisting bacteria and promoting wound healing and a preparation method thereof, aiming at the defects in the prior art.

The invention relates to a composite aerogel dressing which is prepared from the following raw materials in percentage by mass: 4-10% of polyvinyl alcohol, 5-50% of water-soluble chitosan, 0.1-3% of graphene oxide and the balance of deionized water.

Further, the polymerization degree of the polyvinyl alcohol is 1700, and the alcoholysis degree is 99%.

Further, the water-soluble chitosan is water-soluble carboxymethyl chitosan.

The preparation method of the composite aerogel dressing comprises the steps of preparing a mixed solution according to the mass percentage, freezing the mixed solution, then unfreezing the mixed solution for multiple times to obtain hydrogel, and freezing and drying the obtained hydrogel to obtain the composite aerogel dressing.

Further, the specific preparation steps of the composite aerogel dressing are as follows:

(1) preparing a polyvinyl alcohol aqueous solution with the mass fraction of 4-10%, adding 5-50% of water-soluble chitosan and 0.1-3% of graphene oxide into the polyvinyl alcohol aqueous solution, uniformly stirring at room temperature, and standing for defoaming;

(2) pouring the solution obtained in the step (1) into a plastic culture dish, freezing for 22-24 h at-18 to-20 ℃, unfreezing for 2-4 h at room temperature, and circulating the process for 1-3 times to obtain hydrogel;

(3) and (3) putting the hydrogel obtained in the step (2) into a freeze dryer for freeze drying for 2-4 days to obtain the composite aerogel dressing.

The composite aerogel dressing comprises graphene oxide, polyvinyl alcohol and chitosan, wherein the graphene oxide is a promising nano material, has a large surface area, and has a large number of functional groups such as hydroxyl, carboxyl and epoxy groups on the surface. The graphene oxide has various practical properties including excellent chemical stability, mechanical properties, biocompatibility, hydrophilicity and the like, and the addition of the graphene oxide can improve the mechanical properties, biological activity and drug slow-release performance of the material without inducing cytotoxicity and can promote the growth and proliferation of cells.

Polyvinyl alcohol is a water-soluble high molecular polymer, is nontoxic and harmless to human bodies, and has good biocompatibility, biodegradability and excellent mechanical properties. Under the condition of repeated freezing and thawing of the polyvinyl alcohol, hydrogen bonds can be formed between molecules and in molecules of the polyvinyl alcohol, so that hydrogel with a three-dimensional network structure is formed, and the use of toxic chemical cross-linking agents such as glutaraldehyde and the like is avoided.

The water-soluble carboxymethyl chitosan is a derivative of chitosan, has the functions of rapidly healing wounds and preventing wound infection, has good water solubility, and can reduce toxic and side effects on human bodies.

The composite aerogel dressing which has good elastic flexibility, excellent mechanical property and the functions of stopping bleeding, resisting bacteria and promoting wound healing is prepared by using the polyvinyl alcohol and the water-soluble chitosan as raw materials, fully combining the advantages of the polyvinyl alcohol and the water-soluble chitosan, simultaneously making up the respective defects and synchronously introducing the graphene oxide.

The preparation method of the aerogel dressing disclosed by the invention is combined with a freezing and thawing method, an ion crosslinking method and a freeze drying method. The preparation method is simple to operate and environment-friendly, and the prepared aerogel dressing is changed into hydrogel from aerogel after absorbing wound exudate, and the hydrogel can resist the invasion of bacteria, prevent infection and well adhere to a wound surface; the wound dressing is moisture permeable and air permeable, and provides a moist environment for wound healing; can not bring secondary damage to the wound when changing the dressing.

The freezing and thawing method makes polyvinyl alcohol molecules and molecules connected together through hydrogen bonds, and is physical crosslinking, so that toxic chemical crosslinking agents such as boric acid, glutaraldehyde and the like are avoided.

The composite aerogel dressing has the functions of stopping bleeding, resisting bacteria and promoting wound healing, and has the advantages of low cost, environmental protection, simple preparation process, no special requirement on equipment and better biocompatibility, and great potential in the aspect of medical wound dressings.

Drawings

FIG. 1 is a cross-sectional view of the composite aerogel obtained in example 2.

Detailed Description

The following are specific embodiments of the present invention and are further described with reference to the drawings, but the present invention is not limited to these embodiments.

Example 1:

(1) PVA powder is added into deionized water, heated and stirred for 2 hours at 95 ℃ to obtain 4 wt% PVA aqueous solution. Adding water-soluble carboxymethyl chitosan (the water-soluble carboxymethyl chitosan accounts for 20 percent of the PVA mass) into a 4 weight percent PVA solution, and stirring for a period of time at normal temperature until a uniform mixed solution is formed.

(2) Adding GO (the mass of GO accounts for 0.5% of the mass of the PVA) into the PVA/CMCS mixed solution obtained in the step (1), stirring for a period of time to form a uniform mixed solution, and standing overnight to remove bubbles.

(3) Pouring the GO/PVA/CMCS mixed solution obtained in the step (2) into a plastic culture dish, freezing for 22h at-18 ℃, and unfreezing for 2h at room temperature. Freeze thaw cycles 1 time.

(4) And (4) putting the hydrogel obtained in the step (3) into a freeze dryer for freeze drying for 3 days to obtain the graphene oxide/polyvinyl alcohol/water-soluble chitosan composite aerogel dressing.

Example 2:

(1) PVA powder is added into deionized water, heated and stirred for 2 hours at 95 ℃ to obtain 4 wt% PVA aqueous solution. Adding water-soluble carboxymethyl chitosan (the water-soluble carboxymethyl chitosan accounts for 25 percent of the PVA mass) into a 4 weight percent PVA solution, and stirring for a period of time at normal temperature until a uniform mixed solution is formed.

(2) Adding GO (the mass of GO accounts for 1% of the mass of the PVA) into the PVA/CMCS mixed solution obtained in the step (1), stirring for a period of time to form a uniform mixed solution, and standing overnight to remove bubbles.

(3) Pouring the GO/PVA/CMCS mixed solution obtained in the step (2) into a plastic culture dish, freezing for 24h at-18 ℃, and unfreezing for 4h at room temperature. Freeze thaw cycles 2 times.

(4) And (4) putting the hydrogel obtained in the step (3) into a freeze dryer for freeze drying for 3 days to obtain the graphene oxide/polyvinyl alcohol/water-soluble chitosan composite aerogel dressing. The scanning cross-sectional view of the resulting composite aerogel is shown in fig. 1.

Example 3:

(1) PVA powder is added into deionized water, heated and stirred for 2 hours at 95 ℃ to obtain 4 wt% PVA aqueous solution. Adding water-soluble carboxymethyl chitosan (the water-soluble carboxymethyl chitosan accounts for 30 percent of the PVA mass) into a 4 weight percent PVA solution, and stirring for a period of time at normal temperature until a uniform mixed solution is formed.

(2) Adding GO (the mass of GO accounts for 1.5% of the mass of PVA) into the PVA/CMCS mixed solution obtained in the step (1), stirring for a period of time to form a uniform mixed solution, and standing overnight to remove bubbles.

(3) Pouring the GO/PVA/CMCS mixed solution obtained in the step (2) into a plastic culture dish, freezing for 22h at-18 ℃, and unfreezing for 4h at room temperature. Freeze thaw cycles 3 times.

(4) And (4) putting the hydrogel obtained in the step (3) into a freeze dryer for freeze drying for 3 days to obtain the graphene oxide/polyvinyl alcohol/water-soluble chitosan composite aerogel dressing.

Comparative example 1:

in comparison with example 2, no graphene oxide was added to the PVA/CMCS mixed solution in step (2), and the rest of the procedure was the same as in example 2.

Comparative example 2:

compared with the example 2, 2% of boric acid (based on the mass of PVA) is added into the GO/CMCS/PVA solution in the step (2) and stirred at normal temperature to form a uniform solution. After standing to remove air bubbles, directly pouring into a plastic culture dish to be cooled and dried for 3 days. The rest of the procedure was the same as in example 2.

Comparative example 3:

compared with the example 2, 0.5% of glutaraldehyde (based on the mass of PVA) is added into the GO/CMCS/PVA solution in the step (2) and stirred at normal temperature to form a uniform solution. After standing to remove air bubbles, directly pouring into a plastic culture dish to be cooled and dried for 3 days. The rest of the procedure was the same as in example 2.

The mechanical property, the hemostatic property and the antibacterial effect of the samples obtained in examples 1 to 3 and comparative examples 1 to 3 were tested, the hemostatic property was tested by a hemolysis-coagulation method, the antibacterial effect was tested by a plate counting method, and the test results are shown in the following table.

The above is not relevant and is applicable to the prior art.

While certain specific embodiments of the present invention have been described in detail by way of illustration, it will be understood by those skilled in the art that the foregoing is illustrative only and is not limiting of the scope of the invention, as various modifications or additions may be made to the specific embodiments described and substituted in a similar manner by those skilled in the art without departing from the scope of the invention as defined in the appending claims. It should be understood by those skilled in the art that any modifications, equivalents, improvements and the like made to the above embodiments in accordance with the technical spirit of the present invention are included in the scope of the present invention.