抗菌性壳聚糖复合异种脱细胞真皮基质敷料的制备与性能研究

发布时间：2019-04-17 19:59

【摘要】：目前,异种(猪)脱细胞真皮基质敷料的开发已经成为研究的热点,该敷料可用于不同程度烧伤的治疗。已上市产品普遍存在抗菌性能、生物活性、渗透性不足的缺点,这限制了该类敷料在临床上的应用。本文利用自制的壳聚糖与脱细胞真皮基质复合来解决该类敷料存在的不足:采用氧化降解法制备并选择了一种低聚合度壳聚糖(COS),在本课题组前期研究的基础上,以猪皮为原料,采用物理、化学、生物相结合的方法制备了一种异种(猪)脱细胞真皮基质(PADM),并通过复合、交联低聚合度壳聚糖(COS),制备了抗菌性壳聚糖复合脱细胞真皮基质敷料(COS-PADM)。本课题重点研究了过氧化氢降解法对壳聚糖降解的影响,对不同分子量低聚合度壳聚糖的抑菌性进行研究,并研究了壳聚糖交联复合脱细胞真皮基质的制备工艺。主要结论如下:(1)首先针对反应时间、醋酸浓度、过氧化氢用量等三个条件对壳聚糖的氧化降解方法进行研究。研究表明随着时间的增加,壳聚糖分子量不断降低,其中反应第一小时反应速率较大;醋酸含量为3%时,在相同条件下,降解后壳聚糖的分子量最低;当过氧化氢用量不断增加时,降解后壳聚糖的分子量随之降低,当过氧化氢质量分数为4%以上时,下降速率趋为平缓。对壳聚糖降解的影响,反应时间过氧化氢用量醋酸浓度。(2)对分子量为700、3000、6000、9000、12000左右的壳聚糖对金黄色葡萄球菌和大肠杆菌的抑菌作用进行研究,研究表明:对于金黄色葡萄球菌,分子量9000和12000左右的壳聚糖抑菌效果最好,且其最低抑菌浓度为0.25%。对于大肠杆菌,分子量为3000、6000、9000左右的壳聚糖具有良好的抑菌性,且最低抑菌浓度为0.25%。因此,选用分子量为9000左右的壳聚糖与脱细胞真皮基质复合。(3)在脱细胞真皮基质上复合低聚合度壳聚糖,并对其理化性能进行表征,结果表明,随着壳聚糖用量的增加PADM材料的孔隙率、耐酶解性、抗张强度得到提高,透水汽速率下降。根据抑菌实验表明,COS-PADM具有一定的抗菌性,并且随着壳聚糖用量的提高,抗菌性逐渐提高,能够一定程度上抑制金黄色葡萄球菌和大肠杆菌的繁殖。(4)根据以上(1)(2)(3)的研究结果,结合敷料的临床实际要求和成本考虑,将壳聚糖用量定为3.00%,在该条件下,制备的抗菌性壳聚糖复合脱细胞真皮基质敷料的透水汽速率2947.8 g·m-2.24h-1、孔隙率为93.83%,抗张强度11.91MPa,耐酶解时间25h。本研究制备的壳聚糖复合脱细胞真皮基质敷料具有一定的抗菌性和良好的渗透性,还具有潜在的其他生物学特性,基本符合烧伤敷料的要求,为抗菌性脱细胞真皮基质敷料产品开发奠定了基础。
[Abstract]:At present, the development of xenogeneic (porcine) acellular dermal matrix dressing has become a research hotspot, which can be used to treat different degrees of burn. The shortcomings of antibacterial activity, bioactivity and low permeability of the products on the market limit the clinical application of this kind of dressings. In this paper, the composite of chitosan and acellular dermal matrix was used to solve the deficiency of this kind of dressing. A kind of low polymerization degree chitosan (COS), was prepared and selected on the basis of the previous study of our research group. A kind of xenogeneic acellular dermal matrix (PADM), (porcine acellular dermal matrix) was prepared by physical, chemical and biological methods using pig skin as raw material and crosslinked chitosan (COS), with low degree of polymerization through composite. Antibacterial chitosan composite acellular dermal matrix dressing (COS-PADM) was prepared. In this paper, the effect of hydrogen peroxide degradation on chitosan degradation was studied, the antibacterial activity of chitosan with different molecular weight and low degree of polymerization was studied, and the preparation technology of chitosan crosslinked composite acellular dermal matrix was studied. The main conclusions are as follows: (1) the oxidative degradation of chitosan was studied under the conditions of reaction time, acetic acid concentration and hydrogen peroxide dosage. The results showed that the molecular weight of chitosan decreased with the increase of time, and the reaction rate was higher in the first hour of reaction, when the content of acetic acid was 3%, the molecular weight of chitosan after degradation was the lowest under the same conditions. When the amount of hydrogen peroxide increased, the molecular weight of chitosan decreased after degradation. When the mass fraction of hydrogen peroxide was more than 4%, the rate of decrease became smooth. (2) the bacteriostatic effect of chitosan with molecular weight of 700,3000,6000,9000,12000 on Staphylococcus aureus and Escherichia coli was studied. The results showed that chitosan with molecular weight of about 9000 and 12000 had the best bacteriostatic effect on Staphylococcus aureus, and its minimum inhibitory concentration (MIC) was 0.25%. For Escherichia coli, chitosan with molecular weight of 3,000,6000,9000 had good antibacterial activity, and the minimum inhibitory concentration (MIC) was 0.25%. Therefore, chitosan with molecular weight of about 9000 was selected to composite with acellular dermal matrix. (3) chitosan with low polymerization degree was synthesized on acellular dermal matrix and its physical and chemical properties were characterized. With the increase of chitosan content, the porosity, enzymolysis resistance and tensile strength of PADM materials were improved, and the rate of water permeability decreased. According to the bacteriostatic experiment, COS-PADM has certain antibacterial activity, and with the increase of chitosan dosage, the antibacterial activity increases gradually. It can inhibit the reproduction of Staphylococcus aureus and Escherichia coli to a certain extent. (4) according to the results of (1) (2) (3) above and considering the clinical requirements and cost of dressing, the dosage of chitosan is determined to be 3.0%. Under these conditions, the permeability of the antibacterial chitosan composite acellular dermal matrix dressing was 2947.8 g 路m ~ (- 2) 路h ~ (- 1), the porosity was 93.83%, the tensile strength was 11.91 MPA, and the enzymatic hydrolysis time was 25 h. The chitosan composite acellular dermal matrix dressing prepared in this study has certain antibacterial and good permeability, and also has other potential biological characteristics, which basically accords with the requirements of burn dressing. It lays a foundation for the development of antibacterial acellular dermal matrix dressings.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R318.08

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