聚乳酸类缓释型支架材料的研究与应用意义

目的聚乳酸是具有良好的生物相容性和生物降解特性的聚合物,是美国食品和药品管理局(FDA)认可的一类可植入体内的生物材料.细胞因子在组织工程骨构建中的促进成骨、血管化等作用越来越受到广泛关注.但外源性细胞因子在体内半衰期较短,不能在骨修复局部聚集和保持相对较高浓度.主要分析聚乳酸及其衍生化合物材料可作为多肽及蛋白质类药物的载体,通过其自身降解来调节药物释放,用于骨组织工程研究的研究现状与应用前景.资料来源应用计算机检索Medline 1993/2004文章,检索词为"polylactic acid,bone morphogenetic protein,vascular endothelial growth factor,TGF-β",限定语言English;检索中国期刊网1993/2004医药卫生类文章,限定语言种类中文.资料选择纳入标准①有关聚乳酸及其衍生物构建骨组织工程支架的研究.②聚乳酸类支架负载细胞因子研究.排除标准①陈旧文献.②重复研究.资料提炼共收集到96篇与聚乳酸组织工程支架相关文献,其中23篇纳入引用. 资料综合①聚乳酸/聚乳酸和聚羟基乙酸的共聚物是一种良好的可生物降解的控释骨架,且具有支架和缓释的双重作用.聚乳酸是最早作为骨、软骨组织工程的支架材料,也是目前运用最广泛的骨组织工程材.②骨形态发生蛋白是应用于骨组织工程最多的因子,负载、缓释骨形态发生蛋白的聚乳酸类支架研究最为深入,未见血管内皮生长因子负载于聚乳酸类支架材料研究.结论对于可缓释多种因子的聚乳酸类支架材料的开发与应用已经成为骨组织工程支架新的热点.

Significance of the application of polylactic acid sustained-release scaffold

OBJECTIVE: Polylactic acid (PLA) is a biodegradable polymer possessing good biocompatibility and biodegradability, and approved as a biomaterial for in vivo implantation by American Food and Drug Administration (FDA). The role of cytokines in promoting osteogenesis and vascularization for constructing tissue-engineered bones has received increasing attention.But exogenous cytokine has shorter half-life in vivo and can not reach and maintain relatively high local level for bone repair. This article reviews the present researches and analyzes the application prospect of PLA and its derivatives in bone tissue engineering to serve as the carrier for polypeptide and protein medicines with controlled release through its degradation.DATA SOURCES: Related articles published between 1993 and 2004were searched in Medline database with key words of "polylactic acid,bone morphogenetic protein, vascular endothelial growth factor, TGF- beta", limiting the language to English; meanwhile the related medical papers between 1993 and 2004 were also searched in the Chinese Periodical Database, limiting the language to Chinese.STUDY SELECTION: Related researches on PLA and its derivatives for constructing bone tissue-engineering Scaffolds and study of PLA scaffolds carrying cytokines were included with the obsolete literature and repetitive researches eliminated.DATA EXTRACTION: Altogether 96 related literatures on PLA and its derivatives for constructing bone tissue-engineering scaffolds were collected, 23 of which were included in this review.DATA SYNTHESIS: PLA/PLA-polyglycolic acid copolymer is a good biodegradable scaffold for controlled drug release, having the dual functions as scaffolds and sustained-release drug carrier. PLA is the earliest scaffold material in bone and cartilage tissue-engineering, and also the most widely used tissue-engineering material at present. BMP is the most frequently adopted cytokine in bone tissue-engineering, and PLA scaffolds carrying sustained-release BMP is studies most thoroughly, but researches on PLA scaffolds carrying vascular endothelia growth factor has not been conducted.CONCLUSION: Development and application of PLA scaffolds carrying various sustained-release cytokines has become the new interest in bone tissue-engineering researches.