【作者】 廖红；

【导师】 董志； 傅洁民；

【作者基本信息】 重庆医科大学 ， 药理学， 2004， 硕士

【摘要】 目的：烧烫伤和创伤无论在战时还是平时都是危害人类健康和生命安全的重要疾病之一。烧伤是因物理、化学、放射线等诸多因素作用于机体而造成的一种极其复杂的外伤性疾患，烧伤治疗外治疗法颇多，外用药物治疗在烧伤治疗中占首要地位。理想的烧伤创面用药应该具有镇痛、减少渗出、利于引流、保护创面、促进创面生长、抗菌谱广、不产生或少产生抗药菌株、无毒性、副作用少、创面愈合后疤痕少、价格便宜等特点。目前用于烧伤创面的中西药不下数百种，还未有一种药物能完全达到上述要求。而甲壳素是具备较多这些优良特性的材料之一。壳聚糖，又叫脱乙酰基几丁质、几丁聚糖，是甲壳素（即几丁质）脱去乙酰基后形成的产物，是一种聚阳离子多糖，具有活性氨基和羟基，可与聚阴离子物质结合。由于壳聚糖对人体无毒，生物相容性好，可降解为正常机体的成分，具有止血、抗感染、提高机体免疫力、促进创面皮肤愈合等作用，不仅在其它领域有广泛的应用前景，在烧烫伤、创伤治疗方面也有很高的应用价值。而且壳聚糖来源广泛，其前体甲壳素在世界上存在量为100亿吨左右，仅次于纤维素，是地球上<WP=7>第二大生物资源，它存在于虾蟹等甲壳类动物的外壳中，是一种价廉易得且极具应用价值的生物材料。虽然对壳聚糖的研究较多，但尚未发现以壳聚糖为原料制成的药品的研究。本课题旨在从离体细胞水平和在体动物模型探讨壳聚糖对大鼠Ⅲ度烧伤创面的治疗作用及其相关机制，以期为治疗皮肤烧烫伤提供新的治疗药物，并为其制剂的开发提供药理学依据。方法：离体实验：通过培养小鼠成纤维细胞 L929，检测L929 MTT活性，来研究壳聚糖对L929的促生长作用。在体实验：采用大鼠Ⅲ度烧伤模型，通过检测大鼠烧伤创面愈合时间，创面愈合率，及组织病理形态学的改变，来研究壳聚糖对大鼠Ⅲ度烧伤愈合的作用。在此基础上，继续利用大鼠Ⅲ度烧伤模型，通过检测大鼠烧伤创面组织蛋白质、羟脯氨酸（HOP）、丙二醛（MDA）含量，血小板源性生长因子（PDGF）、超氧化物歧化酶（SOD）活性和表皮生长因子（EGF）、表皮生长因子mRNA（EGFmRNA）的表达等初步探讨壳聚糖的作用机理。结果与结论： （1）壳聚糖在较低浓度（0.01%、0.02%、0.04%）（W/V）时，能够促进L929的生长，而在较高浓度（0. 1%、0.2%、0.4%）（W/V）时，却对L929的增殖产生了抑制作用。提示壳聚糖既能促进创面的愈合，又能防止瘢痕的增生。 <WP=8>（2）壳聚糖（1%、2%、4%）（W/V）对大鼠Ⅲ度烧伤创面具有提高创面愈合率、缩短创面愈合时间的作用，且创面愈合后组织病理学评分显著优于对照组。综上所述，壳聚糖（1%、2%、4%）（W/V）对大鼠Ⅲ度烧伤创面具有显著的治疗作用，并有剂量依赖性。其促愈合作用可能与以下机制有关：①提高创面蛋白和HOP的含量。②显著提高创面内源性抗氧化能力，进而减轻烧伤创面脂质过氧化损伤。③显著上调创面组织EGF、EGFmRNA、PDGF的表达。更多还原

【Abstract】 Objective:Burns and wound are important diseases which are dangerous to the health and the life of people in war or in peace. Covering the wound skin is one of main measures to prevent infection and deal with deep organize of skin effectively. Binding up the wound traditionarily not only can bring scar which is obvious disfigurement in appearance but also cannot deal with the deep tissue of the wound effectly. With the development of technology, people are searching actively a wound remedy which origin abroadly and is made easily. The wound remedy can not only protect the wound but also promote the wound concrescence and improve the quality of concrescence of the wound.Chitosan is a product which chitin is removed of the acetyl. It is a poly-catholyte polysaccharide which posses active Amido and Hydroxy, <WP=10>and can bind to the matter with polyanion. Because chitosan is nonpoisonous to human body and have satisfactory histocompatibility, it also can be degradated into the normal component of body, stanch, anti-infect, improve the body immunity, promote the wound healing, it wound be used widely in many field and is very valuable in burn. Chitosan origin widely. Chitin, its prosoma, is about 100 hundred million ton in the world. Chitin is the second large organism resource in the world only less than cellulose. Chitin exist in the shell of shrimp, crab and so on, so its resource is abundant and it is cheap and valuable. There is no remedy made from chitosan to treat wound now.This present study is investigate whether chitosan can promote the wound healing and its mechanism and to find a new remedy for treating the burned wound and provid the pharmacological basis of the new remedy.Method:In vitro: L929 were cultured, the MTT were assayed so as to investigate whether chitosan can promote L929 growing. In vivo: Rats were burned and chitosan was used to treat wound on the burned skin of rat. Effect of chitosan on the wound healing time, the healing rate of the wound and the change of constitution morphology were investigate on the burned wound of rat. Forthermore, the content of protein, HOP, MDA, and the activity of PDGF and SOD were measured and the <WP=11>expression of EGF, EGFmRNA on the burned skin were observed for studying the mechanism of chitosan.Results and Conclusion:（1）Chitosan (0.01%、0.02%、0.04%)（W/V）can promote L929 growth, but the high concentration of chitosan(0. 1%、0. 2%、0. 4%)（W/V）inhibit L929 growth,which indicated that chitosan wound not only promote the burned wound healing but also inhibit the scar forming.（2）Chitosan (1%、2%、4%)（W/V）promote the wound healing of Ⅲ skin burns in rats significantly,in a dose-dependent manner.（3）The mechanisms of chitosan(1%、2%、4%)（W/V）on the wound healing of Ⅲ skin burns are probably ralated to:①Chitosan increase the content of protein and HOP of the burned wound.②Chitosan relieve the lipid peroxidation of the burned wound.③Chitosan upregulated the expression of EGF、EGFmRNA、PDGF in the burned wound significantly.更多还原