A novel biodegradable bone repair biomaterial of bone-like carbonated apatite with porous structurewas prepared by using self-hardening calcium phosphate cement. Cell culture, degradation in simulated body liq-uid (SBF) and as a carrier for bone morphogenic protein (BMP) controllable releasing experiments were performedto evaluate the biocompatibility, degradation and BMP carrier properties of the porous scaffold. The results revealthat the degradation property of the carbonated apatite is better than hydroxyapatite, the more the content of CO32-in apatite, the faster the degradation of the materials, the cell could attach, proliferate and differentiate on theporous scaffold, indicating that the bone like apatites not only have excellent biocompatibility but are alsobiodegradable and can be used as carriers for BMP controlling release.
目的 研究不同调控方法对不锈钢表面混合药物涂层中紫杉醇释放速率的影响,并对药物的释放机制进行了研究。方法 研究了聚乙烯-乙烯醇(EVAL)和紫杉醇混合涂层中药物的存在状态,并通过改变外层涂层的厚度、引入溶胀控制剂(swell-ing control agent,SCA)、Ar气低温等离子体(low temperature plasma,LTP)轰击等方法调控紫杉醇的释放速率。并运用Higuchi,Hixcon Crowell,Ritger-Peppas等方程分析了药物的释放机制。结果 药物在涂层中以无定型、均匀分散在聚合物中;药物的释放速率随外层涂层厚度的增加而降低;与外层引入SCA相比,在内层药物和高分子中添加SCA更能有效地降低药物的释放速率;Ar气LTP轰击涂层外表面后,药物的释放速率明显加快;随着LTP处理时间的延长,药物的释放速率加快;但LTP的功率对药物的释放速率无明显影响。药物从混合药物涂层中的释放为Fick扩散,而从含SCA体系中的释放为非Fick扩散。LTP处理改变了药物的释放规律。结论 不锈钢表面EVAL和紫杉醇混合涂层中药物的释放速率可以通过适当的方法进行调控。
