CN109966540B

CN109966540B - Preparation method and application of nano chitin composite calcium alginate medical dressing

Info

Publication number: CN109966540B
Application number: CN201910271457.9A
Authority: CN
Inventors: 杜予民; 庞知益; 高慧敏; 钟自彪; 夏浩洋; 叶啟发
Original assignee: Wuhan University WHU
Current assignee: Wuhan University WHU
Priority date: 2019-04-04
Filing date: 2019-04-04
Publication date: 2020-06-23
Anticipated expiration: 2039-04-04
Also published as: CN109966540A

Abstract

The invention discloses a preparation method and application of a nano chitin composite calcium alginate medical dressing, and relates to the field of biomedical materials. The method comprises the following steps: mixing nano chitin obtained by TEMPO oxidation with sodium alginate, calcium carbonate and softener according to different proportions, stirring uniformly, adding a certain amount of glucolactone, stirring for several minutes, pouring into a mould, standing for several hours to fully gel, and freeze-drying to obtain the spongy medical dressing. Compared with the traditional gauze, the dressing has remarkable effect of promoting wound healing. The method has the advantages of simple production process, controllable processing, low cost, no toxicity, and suitability for large-scale production. Can be used as biomedical materials, and particularly has wide application prospect in the fields of wound repair and the like.

Description

Preparation method and application of nano chitin composite calcium alginate medical dressing

Technical Field

The invention belongs to the field of biomedical materials, and particularly relates to a preparation method and application of a nano chitin composite calcium alginate medical dressing.

Background

Hundreds of millions of people worldwide need to perform surgical operations every year, and the medical dressing is used for wrapping wounds, so that the temporary barrier effect is achieved for the wounds, and wound infection is avoided or controlled to protect the human body. At present, traditional single dressings such as gauze are still commonly used for surgical wounds, but the traditional dressings have the defects of poor antibacterial property, poor capability of absorbing exudates, slow healing time and the like. With the improvement of the life quality of people, the requirements of surgical patients on wound healing, comfort and the like are correspondingly improved, and the shortening of the rehabilitation time is more hopeful. So the development of new medical dressing which is beneficial to wound healing and disease rehabilitation is receiving more and more attention. In general, new medical dressings have good breathability; the liquid absorption capacity is strong; certain moisture retention can keep the moist environment of the wound so as to be beneficial to wound healing; can stop bleeding; has antibacterial property. Compared with the traditional dressing, the novel medical dressing can shorten the wound healing time, reduce the dosage of the medical dressing, obviously shorten the nursing time and meet the requirements of patients. Therefore, new medical dressings with greater comfort, accelerated wound healing and biocompatibility have also met with a higher rate of development.

The sodium alginate is a natural polysaccharide extracted from seaweed, has good biocompatibility, biodegradability and excellent hygroscopicity, has no toxic or side effect on a human body, and is an ideal raw material for preparing novel medical dressings. The medical dressing designed and synthesized by taking sodium alginate as a raw material has various types, and the main forms comprise sponge, fiber, gel and other forms. However, the single sodium alginate medical dressing has the defect of low cell adhesion, and the dry calcium alginate sponge is brittle, is not suitable for bending and is not easy to wrap.

Chitin is a natural polysaccharide with important biological functions and widely exists in crustaceans, insects and squid parietal bones. Has excellent cell compatibility, good biocompatibility and biodegradability, and can enhance the immunologic function, accelerate wound healing, relieve pain and stop bleeding.

Therefore, how to compound chitin and sodium alginate enables the prepared dressing to have the advantages of multiple materials so as to meet the requirement of wound healing, and the dressing is a difficult problem in the development of novel medical dressings.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention mainly aims to provide a preparation method of a nano chitin composite calcium alginate medical dressing for treating wounds such as burns, scalds and operation wounds. Mixing nano chitin obtained by TEMPO oxidation with sodium alginate, calcium carbonate and softener according to different proportions, stirring uniformly, adding a certain amount of glucolactone, stirring for several minutes, pouring into a mould, standing for several hours to fully gel, and freeze-drying to obtain the spongy medical dressing. The method has simple preparation process and is suitable for large-scale production.

The second purpose of the invention is to provide the medical dressing obtained by the preparation method, and the dressing has excellent air permeability, water absorption, flexibility, biocompatibility and degradability. Compared with the traditional gauze, the dressing has remarkable effect of promoting wound healing.

The third purpose of the invention is to provide the application of the medical dressing in the field of biomedical materials.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, a preparation method of a nano chitin composite calcium alginate medical dressing is provided, which comprises the following steps:

(1) oxidizing α -chitin or β -chitin by TEMPO to respectively obtain α -chitin nanowhiskers and β -chitin nanofibers, and preparing a water dispersion solution, wherein the components comprise 0.05-2.5 wt% of the nano chitin and the balance of water;

(2) adding calcium carbonate into the aqueous dispersion obtained in the step (1), stirring and dispersing, adding sodium alginate powder to make the concentration of the sodium alginate powder be 0.5-3 wt%, adding a softener to make the concentration of the softener be 0-10 wt%, and stirring and dissolving, wherein the mass of the calcium carbonate is 5-20% of that of the sodium alginate;

(3) preparing a fresh gluconolactone solution, adding the gluconolactone solution into the mixed solution obtained in the step (2), stirring or vortexing for 1-2 minutes, pouring the gluconolactone solution into a mold, standing for several hours, and freeze-drying once to obtain the porous three-dimensional nano chitin/calcium alginate sponge, wherein the added gluconolactone solution is 2 times of the calcium carbonate solution obtained in the step (2);

(4) cutting and packaging the sponge, Co⁶⁰Irradiating for sterilization to obtain the nanometer chitin/calcium alginate medical dressing.

Further, the process of obtaining α -chitin nanowhiskers and β -chitin nanofibers from α -chitin or β -chitin in step (1) of the above preparation method by TEMPO oxidation respectively comprises:

dispersing 1g of α -chitin or β -chitin in 100g of distilled water, sequentially adding 0.016g of 2,2,6, 6-tetramethyl-1-piperidine alumina (TEMPO) and 0.1g of NaBr, stirring for dissolving, dropwise adding 5mmol of NaClO solution, maintaining the pH of a reaction system to be equal to 10 by using NaOH solution, finishing the reaction by using a small amount of ethanol when NaOH is not consumed any more, regulating the reaction to be neutral by using HCl solution, centrifuging for 3 times, collecting precipitates, dispersing the precipitates in water, and ultrasonically treating to obtain α -chitin nanowhiskers or β -chitin nanofiber suspension, and storing at 4 ℃ for later use.

Preferably, the component content of the nano chitin in the step (1) of the preparation method is 0.5-1 wt%.

Preferably, the softener in the step (2) of the preparation method is polyethylene glycol or glycerol.

Preferably, the concentration of the added sodium alginate in the step (2) of the preparation method is 1-2 wt%.

Preferably, the mass ratio of the nano chitin to the sodium alginate in the step (2) of the preparation method is 1: 10-1: 1.

Further, in the step (2) of the preparation method, the mass ratio of the nano chitin to the sodium alginate is 1: 2-1: 4

In a second aspect, a medical dressing prepared by the preparation method is provided.

In a third aspect, the application of the medical dressing in the field of biomedical materials is provided.

The principle of the invention is as follows: the chitin whisker or the nano-fiber obtained by oxidizing the chitin TEMPO has higher length-diameter ratio, large specific surface area and high modulus, and also keeps the inherent biological activity of the chitin. The surface of the sponge contains a large amount of carboxyl, and the sponge and sodium alginate are easily compounded to obtain the sponge with the three-dimensional porous structure. The addition of chitin can increase cell adhesion and is more beneficial to wound healing.

Compared with the prior art, the invention has the beneficial effects that:

1. the dressing has the advantages that the matrix material (sodium alginate), the compound type, the compound amount and the product form are controllable, and the application range is greatly improved.

2. The medical dressing prepared by the invention has excellent air permeability, flexibility, water absorption, moisture retention, biocompatibility and biodegradability. Can accelerate cell growth, resist bacterial invasion, prevent wound infection, avoid adhesion to wound, and is easy to remove, thus laying a foundation for further clinical application.

3. The preparation method is simple, mild in reaction, easy to operate, low in energy consumption, environment-friendly and suitable for industrial production.

4. The medical dressing prepared by the invention is formed in one step, has a three-dimensional porous structure, can replace a pure calcium alginate medical dressing, is expected to be widely applied in the fields of biomedical materials and the like in the future, and is particularly suitable for treating wound surfaces of burns, scalds and the like.

Drawings

Fig. 1 is a Scanning Electron Microscope (SEM) image of a cross section of a sponge dressing prepared in example 1 of the present invention.

FIG. 2 shows the cytotoxicity test data of the sponges prepared in examples 1 and 2 of the present invention and comparative example,

MC3T3-E1 cells were selected for experimental detection, and the blank control was PBS solution.

FIG. 3 is a photograph showing the appearance of burn wounds of rats treated with the sponge dressing prepared in example 1 of the present invention on different days and the change of inflammatory factor concentration,

a is the appearance picture of the wound on different days, B is the statistical chart of the wound area on different days, and C is the concentration change of the inflammatory factor TNF α.

Detailed Description

The features and advantages of the present invention will be further understood from the following detailed description taken in conjunction with the accompanying drawings. The examples provided are merely illustrative of the method of the present invention and do not limit the remainder of the disclosure in any way.

The chitin used in the following examples is commercially available chitin derived from shells of crustaceans such as shrimps and crabs, squid, and cuttlefish parietal bone.

α -chitin or β -chitin get α -chitin nano whisker, β -chitin nanofiber respectively through TEMPO oxidation, include:

[ example 1 ]

Adding 0.0182g of calcium carbonate into 10g of 0.5 wt% β -chitin nano-fiber, stirring and dispersing, adding 0.2g of sodium alginate powder and 0.05g of glycerol, stirring and dissolving, adding 0.0647g of gluconolactone, stirring for 2 minutes, pouring into a mold, standing for 24 hours, freeze-drying, cutting, packaging, and adding Co⁶⁰And (3) performing irradiation disinfection to obtain the nano chitin/calcium alginate medical dressing.

[ example 2 ]

Taking 10g of 0.5 wt% α -chitin nanowhisker, adding 0.0182g of calcium carbonate, stirring and dispersing, adding 0.2g of sodium alginate powder and 0.05g of glycerol, stirring and dissolving, adding 0.0647g of gluconolactone, stirring for 2 minutes, pouring into a mould, standing for 24 hours, freeze-drying, cutting, packaging, and obtaining the product Co⁶⁰And (3) performing irradiation disinfection to obtain the nano chitin/calcium alginate medical dressing.

[ example 3 ]

Adding 0.0182g of calcium carbonate into 10g of 0.25 wt% β -chitin nano-fiber, stirring and dispersing, adding 0.2g of sodium alginate powder and 0.025g of glycerol, stirring and dissolving, adding 0.0647g of gluconolactone, stirring for 2 minutes, pouring into a mold, standing for 24 hours, freeze-drying, cutting, packaging, and adding Co⁶⁰And (3) performing irradiation disinfection to obtain the nano chitin/calcium alginate medical dressing.

[ example 4 ]

Taking 10g of 0.05 wt% β -chitin nano-fiber, adding 0.0045g of calcium carbonate, stirring for dispersion, adding 0.05g of sodium alginate powder, stirring for dissolution, adding 0.0162g of gluconolactone, stirring for 1 minute, pouring into a mold, standing for 6 hours, and coolingFreeze drying; dicing, packaging, Co⁶⁰And (3) performing irradiation disinfection to obtain the nano chitin/calcium alginate medical dressing.

[ example 5 ]

Adding 0.0045g calcium carbonate into 10g of 0.5 wt% β -chitin nanofiber, stirring for dispersion, adding 0.05g sodium alginate powder and 0.0125g glycerol, stirring for dissolution, adding 0.0162g gluconolactone, stirring for 1 min, pouring into a mold, standing for 6 hours, freeze-drying, cutting, packaging, and adding Co⁶⁰And (3) performing irradiation disinfection to obtain the nano chitin/calcium alginate medical dressing.

[ example 6 ]

Adding 0.0091g calcium carbonate into 10g of 0.125 wt% β -chitin nano-fiber, stirring and dispersing, adding 0.1g sodium alginate powder and 0.2g polyethylene glycol, stirring and dissolving, adding 0.0324g gluconolactone, stirring for 1 min, pouring into a mould, standing for 12 hr, freeze-drying, cutting, packaging, and adding Co⁶⁰And (3) performing irradiation disinfection to obtain the nano chitin/calcium alginate medical dressing.

[ example 7 ]

Adding 0.0091g calcium carbonate into 10g of 1 wt% α -chitin nanowhisker, stirring for dispersion, adding 0.1g sodium alginate powder and 0.5g polyethylene glycol, stirring for dissolution, adding 0.0324g gluconolactone, stirring for 1 min, pouring into a mold, standing for 12 hr, freeze drying, cutting, packaging, and adding Co⁶⁰And (3) performing irradiation disinfection to obtain the nano chitin/calcium alginate medical dressing.

[ example 8 ]

Adding 0.0273g of calcium carbonate into 10g of 2 wt% α -chitin nanowhisker, stirring for dispersion, adding 0.3g of sodium alginate powder and 1g of glycerol, stirring for dissolution, adding 0.0971g of gluconolactone, stirring for 2 minutes, pouring into a mold, standing for 24 hours, freeze-drying, cutting, packaging, and adding Co⁶⁰And (3) performing irradiation disinfection to obtain the nano chitin/calcium alginate medical dressing.

Comparative example

Respectively adding 0.2g of sodium alginate powder and 0.0182g of calcium carbonate into 10g of distilled water, and stirring for dissolving; 0.0647g of gluconolactone was added, stirred for 2 minutes, and poured into a mold. Standing for 24 hours, and freeze-drying; cutting, packaging, and Co60 irradiation sterilizing to obtain pure calcium alginate sponge.

Cytotoxicity assays

The sponges obtained in examples 1 and 2 and comparative example were incubated at room temperature in a PBS solution containing MC3T3-E1 cells. Fig. 2 is MTT cytotoxicity data of the sponge, and it can be seen from the data that the number of cells of the composite sponge is higher than that of the pure calcium alginate sponge, indicating that the introduction of the nano chitin effectively improves the cell compatibility of the sponge and promotes the growth and proliferation of osteoblasts.

Wound healing test

The wound healing promoting effect of the dressing described in example 1 was evaluated. The aging relationship between the dressing described in example 1 and medical gauze of a control group as a wound dressing was studied by using a rat full-thickness skin wound as a model and a burn wound diameter of 15 mm. Wherein, the age of the rat is as follows: 7-8 weeks; weight: 250-300 g; males, randomized into 2 groups: gauze groups, example 1 groups, 5 per group.

Typical photographs of the healing process are shown in fig. 3A and 3B, and a significant increase in healing was observed in the example 1 group, showing that the contraction healing of the rat wound was significantly accelerated in the example 1 group compared to the gauze group, the example 1 group showed significant wound contraction phenomena 6 days after the operation, the example 9 day, the example 1 group had good wound healing effect, and the regenerated epithelium had substantially covered the wound, the example 1 group had faster and better regeneration process of the de-epithelialization, had more uniform thickness of granulation tissue than the gauze group, and the wound healing process would benefit from a better formation of granulation tissue, in addition, while promoting wound healing, example 1 had better biocompatibility, stimulating the body to produce inflammatory factor TNF α without significant change than the gauze (day 3, day 0.3054, day 9, day 0.3502) (fig. 3C), the results of the study show that the novel nano-sized/calcium alginate dressing can promote wound healing by promoting regeneration, the wound dressing and the chitosan dressing in the example 1 group were completely healed as wound dressing, and the wound dressing was completely healed on day 14 and day 14, respectively.

Claims

1. A preparation method of a nano chitin composite calcium alginate medical dressing is characterized by comprising the following steps:

(1) oxidizing α -chitin or β -chitin by TEMPO to respectively obtain α -chitin nanowhiskers and β -chitin nanofibers, namely nano chitin, preparing the nano chitin into a water dispersion liquid, wherein the nano chitin comprises 0.05-2.5 wt% of nano chitin and the balance of water;

(2) adding calcium carbonate into the aqueous dispersion obtained in the step (1), stirring and dispersing, adding sodium alginate powder to make the concentration of the sodium alginate powder be 0.5-3 wt%, adding a softener to make the concentration of the softener be 0-10 wt%, stirring and dissolving, wherein the mass ratio of the nano chitin to the sodium alginate is 1: 10-1: 1, and the mass of the calcium carbonate is 5-20% of the mass of the sodium alginate;

2. The method for preparing the nano chitin composite calcium alginate medical dressing as claimed in claim 1, wherein the component content of the nano chitin in the step (1) is 0.5-1 wt%.

3. The method for preparing the nano chitin composite calcium alginate medical dressing according to claim 1, wherein the softener in the step (2) is polyethylene glycol or glycerol.

4. The method for preparing the nano chitin composite calcium alginate medical dressing as claimed in claim 1, wherein the concentration of the added sodium alginate in the step (2) is 1-2 wt%.

5. The preparation method of the nano chitin composite calcium alginate medical dressing as claimed in claim 1, wherein the mass ratio of the nano chitin to the sodium alginate in the step (2) is 1: 2-1: 4.

6. A medical dressing produced by the production method according to any one of claims 1 to 5.

7. Use of the medical dressing according to claim 6 in the field of biomedical materials.