可吸收聚乳酸植入材料的实验观察

An Experimental study of Resorbable Materials of Poly-lactic Acid

用国产可吸收聚乳酸材料进行体内、体外实验。体内实验分别将２０个试件植入５只兔体内，于术后不同时间观察其分子量，重量、形态变化及相应的组织反应。体外实验分别将试件浸泡于中性蒸馏水中，观察处理后ｐＨ值、分子量及拉伸强度变化。结果表明聚乳酸材料所引起的组织反应为轻度的无菌性炎症反应。体内、外实验结果均表明聚乳酸分子量降解较快，但试件在一定时间内维持形状不变，同时浸泡液的ｐＨ值亦稳定。伴随分子量的降解有拉伸强度的相应降低。

AbstractBiodegradation of polylactic-acid(PLA),which wasmade in China,was investigates in vivo and in vitro.Invivo,total of 20 implants of PLA were implanted in fiverabbits for 2to 16 weeks.The arounding tissue reaction,degradation and resorption of PLA have been investigat-ed.In vitro,implants were submerged in instilled solutionto observe the variation of pH,degradation and mechanicalproperty.It demonstrated the tissue reaction was mild,andthe degradation of PLA was obvious,but the contour ofimplants was no obvious change within the first 12 weeksin vitro.There was a resorption following the degradationof PLA,and at the same time,there was a decrease of me-chanical property of PLA.The present results show PLA isa promising implant material in future,but it is necessaryto modify the present PLA in order to raising its moleculeweight,improving mechanical property and slowing downthe degradation.