针对糖尿病创口的抑菌敷料制备及促愈合性能评价

发布时间：2018-08-11 20:48

【摘要】：促进难愈合伤口的愈合至今仍是临床上普遍存在的难题,而糖尿病病人创口更是经久难愈,将直接影响病人的身体健康和生活质量。目前,临床上对于难愈合创口的治疗,主要采用药物联合敷料来进行,常用的敷料主要有传统敷料、新型湿性敷料。传统敷料几乎没有促愈合功效。新型湿性敷料能防止异物及空气中的细菌侵入伤口,能够有效减少感染的几率,但其在湿润环境下吸收渗液的特性及透水气性差,最终感染情况出现较多。制备一种抑菌能力强、促愈合效果好、并能维持创面水分平衡的新型敷料具有深远的学术意义和临床应用价值。由于敷料要与患者创面处的组织直接接触,应具有优异的血液相容性、抑菌性及优良的物理性能。丝素蛋白是一种来源广泛的天然蛋白质,具有优越的生物相容性,同时具有一定的抑菌性能,分解后产生的氨基酸能为创面提供营养物质。壳聚糖是一种天然多糖,具有优异的止血止痛性、抑菌性和机体组织相容性,与丝素蛋白按照一定的比例混合后抑菌性随之增强。生物活性玻璃是由无机成分制备得到,其中所含的钙、磷离子能在体液中沉积,并形成羟基磷灰石层,非常有利于细胞的生长,能促进组织吸收营养物质及氧气的进入。聚乙烯醇水凝胶含水量很高,易于改性、接枝,同时具有良好的生物相容性,现已广泛用于生物材料及医药行业。因此,本课题将丝素蛋白、壳聚糖、生物活性玻璃及聚乙烯醇进行共混改性,以突出各材料的优点,制备一种抑菌促愈合伤口敷料。本课题采用搅拌共混的方式依次加入丝素蛋白溶液、壳聚糖溶液,二者混合均匀后加入生物活性玻璃粉末,将三者混合均匀后加入聚乙烯醇溶液,得到丝素蛋白/壳聚糖/生物活性玻璃/聚乙烯醇混合液,经反复冷冻-解冻后即得到抑菌促愈合敷料,并对该敷料的物理性能、抑菌性能、促伤口愈合性能、生物学性能进行了评价。敷料的物理学性能结果表明,敷料具有促进细胞生长的孔隙率,具有维持创面水分平衡的吸水率和保水率,通过调整各材料的比例可以改变其物理性能,在PVA/CS为4/6时敷料的物理性能最佳,透水气性能最接近医用敷料的理想值;从敷料浸提液的抑菌性结果可知,敷料对革兰氏菌及绿脓杆菌均具有较强的抑制作用,并且随着浸提浓度的增加其对细菌的抑制作用增强;敷料的促愈合性能结果表明,抑菌促愈合敷料能有效促进糖尿病大鼠创面的愈合,在同一时相点实验组的创面愈合率均高于海藻酸钠敷料、生物活性玻璃及空白对照;细胞毒性(MTT法)结果表明,抑菌促愈合敷料对细胞没有细胞毒性,各实验组评分均为0级,细胞相对增殖率(RGR)均大于100%,能促进细胞生长;血液相容性结果表明,各实验组溶血度均小于5%,且当PVA/CS为4/6时,敷料的溶血度最低;各实验组材料在50min时BCI值均高于70%;各不同比例敷料的血小板粘附率均低于40%,符合直接接触血液用材料的安全性要求;皮肤刺激实验结果表明,不同比例抑菌促愈合伤口敷料的浸提液及阴性对照对组皮肤均无刺激性,没有红斑、水肿,皮肤显示正常,而阳性对照组却出现了异常情况,有明显的水肿、红斑,抑菌促愈合敷料对皮肤没有刺激性,实验记为0分;急性全身毒性结果表明,实验组与对照组动物均未出现异常,脏器均未出现红肿、充血等病理现象,实验组与对照组的体重增长率、食物利用率、体重相对增长数这三组实验数据均不存在显著性差异。研究表明,该抑菌促愈合敷料具有优异的物理性能、抑菌性能、促愈合性能及生物学性能,有望作为治疗难愈合创口的敷料使用。
[Abstract]:Promoting the healing of hard-to-heal wounds is still a common clinical problem, and diabetic wounds are more difficult to heal for a long time, which will directly affect the health and quality of life of patients. Wet dressings. Traditional dressings have little healing effect. New wet dressings can prevent foreign bodies and bacteria in the air from invading the wound, and can effectively reduce the risk of infection. However, in a humid environment, the characteristics of absorption of exudate and permeability of water are poor, resulting in more infections. Preparation of a strong bacteriostatic, good healing effect, and The new dressing, which can maintain the water balance of wound surface, has far-reaching academic significance and clinical application value. Because the dressing should have excellent blood compatibility, bacteriostasis and excellent physical properties if it is to be directly contacted with the tissue of wound surface, silk fibroin is a natural protein with a wide range of sources and excellent biocompatibility. Chitosan is a kind of natural polysaccharide with excellent hemostatic and analgesic properties, bacteriostatic properties and tissue compatibility. The antibacterial properties of chitosan mixed with silk fibroin in a certain proportion are enhanced. Bioactive glass is prepared from inorganic components. It is found that calcium and phosphorus ions can be deposited in body fluids and form hydroxyapatite layers, which are very conducive to cell growth and promote the absorption of nutrients and oxygen into tissues. Pharmaceutical industry. Therefore, silk fibroin, chitosan, bioactive glass and polyvinyl alcohol were blended and modified to produce a wound dressing which can inhibit bacteria and promote wound healing. Silk fibroin/chitosan/bioactive glass/polyvinyl alcohol mixture was obtained by mixing the three kinds of glass powder and adding PVA solution. After repeated freezing-thawing, the antibacterial and healing dressing was obtained. The physical properties, antibacterial properties, wound healing properties and biological properties of the dressing were evaluated. The results showed that the dressing had the porosity of promoting cell growth, the water absorption rate and the water retention rate of maintaining the water balance of wound surface, and the physical properties of the dressing could be changed by adjusting the proportion of each material. When PVA/CS was 4/6, the physical properties of the dressing were the best, and the permeability was the closest to the ideal value of the medical dressing. The results showed that the dressing had strong inhibitory effect on both Gram bacillus and Pseudomonas aeruginosa, and its inhibitory effect on bacteria increased with the increase of the concentration of extract. The results showed that the dressing could effectively promote wound healing in diabetic rats, and wound healing in the experimental group at the same time point. The results of cytotoxicity (MTT) showed that the dressing had no cytotoxicity to cells, and the scores of each experimental group were all 0, and the relative cell proliferation rate (RGR) was more than 100%, which could promote cell growth. The hemolysis degree of each experimental group was less than 5%. When PVA/CS was 4/6, the hemolysis of the dressing was the lowest; the BCI values of the experimental groups were higher than 70% at 50 min; the platelet adhesion rates of the dressings with different proportions were all lower than 40%, which met the safety requirements of direct contact with blood materials; the skin irritation test results showed that the extracts of the dressings with different proportions of bacteriostasis and wound healing and negative control. No irritation to the skin, no erythema, edema, skin showed normal, while the positive control group showed abnormal conditions, there was obvious edema, erythema, bacteriostasis and healing dressing on the skin no irritation, the experimental score was 0; acute systemic toxicity results showed that the experimental group and the control group animals did not appear abnormal, organs did not appear red. There was no significant difference between the experimental group and the control group in the growth rate of body weight, food utilization rate and the relative growth of body weight. Use of dressings.
【学位授予单位】：重庆理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R318.08

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