摘要
利用纳米β-磷酸三钙/聚乳酸(β-TCP/PLA92)复合材料制备内外双层结构的颈椎椎间融合器.考察了β-TCP重量百分数为10%,30%和60%的外支架复合材料在磷酸盐缓冲溶液中的降解行为、机械性能和热力学性质.结果表明,体外降解30周,降解液的pH>6.9,材料失重率<1.1%,外观形态完好;PLA分子量下降50%以上,复合材料机械性能明显下降,但10%和60%TCP的复合材料抗压强度均大于50 MPa,满足椎间融合器的临床应用要求.10%TCP的复合材料降解过程中,PLA发生了明显的结晶,而其余材料则不明显,说明β-TCP的存在不利于PLA结晶.乳液相分离/粒子沥滤法制得了大孔235～435μm和小孔1～10μm并存的复合孔结构的内层支架.为新型生物可降解颈椎融合器的研制提供了依据.
Totally bioresorbable composites have been prepared from nano-sized β-tricalcium phosphate and a polylactide stereocopolymer（β-TCP/PLA）,aiming at the fabrication of a fusion cage with double layer structure.The composites designed for the outer scaffold contain 10%,30% and 60% of β-TCP,respectively.The degradation behavior,mechanical and thermal properties of the various composites were investigated under in vitro conditions.Results show that the molecular weight of PLA in the composites largely decreased during 30 weeks degradation.However,little changes of weight loss（1.1%）,pH value of the medium（6.9） and sample shape were observed.The compression strength of composites containing 10% and 60% TCP was above 50MPa,thus fulfilling the requirements of clinical applications of fusion cages.PLA crystallized during degradation of the composite containing 10% TCP,in contrast to those of 30% and 60% TCP.This finding shows that the presence of TCP disfavors PLA crystallization.Porous composites with 60% of β-TCP were prepared for the fabrication of the internal scaffold of fusion cage,using phase separation/particle leaching methods.Porous structures with pore sizes of 235—435μm and 1—10μm were obtained.Therefore,this work provides useful information for the fabrication of totally bioresorbable fusion cage.
出处
《复旦学报（自然科学版）》
CAS
CSCD
北大核心
2012年第3期325-334,共10页
Journal of Fudan University：Natural Science
基金
国家自然科学基金资助项目(50873030)
