Significance of the application of polylactic acid sustained-release scaffold / 中国组织工程研究

ABSTRACT

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.