Clinical Application of High Strength poly (L-Lactide) with Osteoductivity

近年来我们研制的超高强度聚L-丙交酯人工骨(棒和螺丝)被证实是安全的，其长期的组织学反应也被阐明。研究了一种表面涂覆AW玻璃陶瓷的新型生物活性复合材料--聚L-丙交酯。植入兔胫骨后，随时间处死动物，进行剥离实验。剥离试验值很低，在0~300g之间，剥离发生在L丙交酯与AW微晶玻璃的界面(包覆层)。聚L-丙交酯的降解在植入后18个月和24个月延迟。研究表明，涂层是L丙交酯与AW玻璃陶瓷复合制备新型生物活性复合材料的关键环节。我们认为，除非两种材料通过不同的方法重新制造成稳定的结构，否则这种贵重材料不能用于临床。我们还使用具有压电性的拉伸聚乳酸(L-丙交酯)薄膜在兔骨缺损模型上进行了另一项实验。4：1拉伸的L-丙交酯薄膜的骨传导性明显好于未拉伸的薄膜。将4：1拉伸的L-丙交酯薄膜与对照的聚乙烯薄膜进行比较，前者骨体积较大。在未来，拉伸聚(L-丙交酯)膜可以作为骨修复的模型，结合骨形态发生蛋白等骨诱导因子。

Ultra high strength poly (L-lactide) osteosynthetic implants (rods and screws) which we have developed in recent years was confirmed to be safety and its long-term histological tissue reaction has also been clarified. A new bioactive composite made of poly (L-lactide) with AW-glass ceramic coated on its surface was studied in vivo. After implantation into the rabbit tibiae, animals were sacrificed with time and a detaching test was performed. The values of detaching tests was very low, ranging from zero to 300 grams, and separation occurred in the interface (coating layr) between poly (L-lactide) and AW-glass ceramic. The degradation of poly (L-lactide) delayd at 18 and 24 months after implantation. From this study, it has been demonstrated that the coating layr was the most critical week point on the new bioactive composite made of poly (L-lactide) with AW-glass ceramic. It is considered that this noble material cannot be used clinically unless both materials are re-manufactured into a stable structure with some different methods.We also performed another experiments using drawn poly (L-lactide) films with piezo-electricity in a rabbit bone defect model. Drawn poly (L-lactide) films by 4 : 1 showed a significantly better osteoconductivity that that of undrawn ones. Drawn poly (L-lactide) films by 4 : 1 and polyethylene films as a control were compared, and the former had a much bone volume. In the future, drawn poly (L-lactide) films can be used as a model for repair of bone defect in combination with osteoinductive factors such as BMP.