【作者】 涂依；

【导师】 肖玲；

【作者基本信息】 武汉大学 ， 环境科学， 2005， 硕士

【摘要】 甲壳素、壳聚糖是天然高分子化合物,具有独特的化学结构,无毒无害,由于其良好的生物相容性、生物活性、生物可降解性,是开发医用材料的理想原材料。对壳聚糖进行改性可以进一步提高壳聚糖的性能,满足多方面的要求。如引进羧甲基的羧甲基壳聚糖有优良的水溶性、吸湿保湿性和成膜性等。壳聚糖季铵化可强化壳聚糖的吸水性、抑菌性和止血功能,这些壳聚糖衍生物在医药领域都有很广阔的应用前景。将壳聚糖与壳聚糖衍生物复合使用可获得性能更好的新型材料,扩展其在医药领域的应用。 本文综述了人工皮肤及壳聚糖衍生物在人工皮肤应用方面的研究进展,对壳聚糖复合膜的构建与性能进行了研究,探讨了影响膜的力学性能、吸水性能、抑菌性能的因素,并用动物实验初步探讨了复合膜作为人工皮肤的使用效果。 主要研究内容和结论如下: (1)以戊二醛为交联剂,在壳聚糖膜上涂敷壳聚糖季铵盐,制备了壳聚糖/壳聚糖季铵盐复合膜,并研究了壳聚糖季铵盐的取代度和戊二醛用量对复合膜各种性能的影响。用盐酸环丙沙星作为模型药物进行膜后载药,探讨了复合膜的药物缓释性能。结果表明:当交联剂用量为壳聚糖季铵盐质量的0.2%时,膜的抗张强度最大;所有复合膜的吸水率和抑菌性随着取代度增大而增加,随着交联剂用量增加而下降。膜的载药量随取代度和交联剂用量的增加而变小,载药膜有较好的药物缓释性能,药物释放可达180h。 (2)以戊二醛为交联剂,在壳聚糖膜上涂敷羧甲基壳聚糖,制备了壳聚糖/羧甲基壳聚糖双层复合膜。研究羧甲基壳聚糖的脱乙酰度、羧甲基取代度及戊二醛用量对复合膜各种性能的影响。用盐酸环丙沙星作为模型药物进行膜后载药,探讨复合膜的药物缓释性能。结果表明:当交联剂和羧甲基壳聚糖的质量比为0.05%时,复合膜的力学性能最好。当羧甲基壳聚糖的脱乙酰度为50%时,复合膜的吸水性最强;羧甲基取代度为0.41时,抑菌性最强。复合膜的载药量随取代度和交联剂用量的增加而变大,药物释放可达150h。 (3)将壳聚糖膜在羧甲基壳聚糖溶液中浸泡,制备出壳聚糖/羧甲基壳聚糖复合膜。用红外光谱和扫描电镜表征了复合膜的结构,并考察了羧甲基壳聚糖分子量对复合膜的力学性能、吸水性能和抗菌性能的影响。结果表明:当羧甲基壳聚糖分子量低于8000时,羧甲基壳聚糖小分子会进入到壳聚糖膜的大分子链中,能够改善壳聚糖膜的力学性能和吸水性能。抗菌实验表明羧甲基壳聚糖分子量大时对革兰氏阳性菌抑制效果较好,而分子量小时对革兰氏阴性菌抑制效果较好。 (4)用动物实验研究壳聚糖/羧甲基壳聚糖双层复合膜和壳聚糖/低分子量羧甲基壳聚糖复合膜的创伤修复效果。实验结果表明:实验膜对创伤都有一定的修复效果,羧甲基壳聚糖分子量越小,创伤修复效果越好。更多还原

【Abstract】 Chitin and chitosan with unique chemical structure are renewable and natural macromoleculer compounds, which are nontoxic, biocompatible, biodegradable. These biopolymers, which have antiseptic and antibacterial functions, are easily modified and could be used as biomedical macromolecular materials. Modifications on chitosan can effectively improve the performances of it to meet different demands. For example, carboxymethyl chitosan is getting more application in medication field as a result of excellent water-solubility and moisture-retention ability. Quaternized chitosan has wide foreground due to its intensification of moisture-absorption antimicrobial ability and hemostasia function. Composites of chitosan and chitosan derivatives should be novel materials of better performances.This paper summarized the research developments of artificial skin and the applications of chitosan derivatives on artificial skin. Chitosan/chitosan derivatives composite membranes were prepared. The structure and properties of composite membranes were studied. The influences of preparation conditions on intension water absorption and antimicrobial ability of composite membranes were discussed. Animal experiments were carried out to discuss effects of composite membranes as skin substitutes.The main contents and conclusions of this paper are described as follows:(1) Chitosan/quaternized chitosan composite membranes were prepared by casting 2-Hydroxypropyltrimethyl ammonium chloride chitosan (HACC ) on chitosan membrane with glutaraldehyde as crosslinking agent. The influence of the degree of quaternization of chitosan(DS) and the amounts of glutaraldehyde (DC ) on properties of composite membranes was discussed. Drug controlling release properties were studied by loading ciprofloxacin on composite membranes. The tensile strength of composite membranes was first increased and then decreased with increasing of DC, the maximum tensile strength was reached when the amount of glutaraldehyde in quaternized chitosan was 0.2%. Water uptaking capacity and antibacterial activities were increased as DS is increased and reduced as DC is increased. The amount of ciprofloxacin loaded on the membranes was decreased with increasing of DS and DC. The releasing time of ciprofloxacin from the membrane can reach 180 hours.(2) Chitosan/carboxymethyl chitosan bilayer composite membranes were prepared by casting carboxymethyl chitosan(CMCS) on chitosan membrane with glutaraldehyde as crosslinking agent. The influence of the deacetylation degree(DD) and substitution degree(DS) of carboxymethyl chitosan, the amounts of glutaraldehyde, on properties of compositemembranes was discussed. Drug controlling release property was studied by loading ciprofloxacin on composite membranes. Results showed that the tensile strength of composite membranes reached maximum value when the content of glutaraldehyde in carboxymethyl chitosan was 0.05%. Water uptaking capacity reached maximum value when DD was 50%. The antibacterial activity of composite membranes reached maximum value when DS was 0.4. The amounts of ciprofloxacin loaded on the membranes increased with increasing of DS and DC. The releasing time of ciprofloxacin from the membrane can reach 150 hours.(3) Chitosan/carboxymethyl chitosan composite membranes were prepared by dipping the chitosan membrane with low-molecular-weight carboxymethyl chitosan solution. The composite membranes were characterized by Fourier transform infrared(FT-IR) and scanning electron microscope(SEM). The influences of molecular weight of carboxymethyl chitosan on tensile strength water absorption and antimicrobial ability of composite membranes were discussed. Results showed that carboxymethyl chitosan with molecular weight under 8000 can enter into chitosan molecule chains and improve tensile strength and water absorption of chitosan membrane. Carboxymethyl chitosan with high molecular weight has better restrain effects on gram-positive bacterium while carboxymethyl chitosan with low molecular weight has better restrain effects on gram-negative bacterium.(4)Chitosan/carboxymethyl chitosan bilayer composite membranes and Chitosan/low-molecular-weight carboxymethyl chitosan composite membranes were prepared to test their wound healing effects by animal experiments . Results showed chitosan/carboxymethyl chitosan composite membranes have effects on the wound healing of animals. The molecular weight of carboxymethyl chitosan is smaller, the effects of wound healing is better.更多还原