生物陶瓷及其复合材料表面诱导类骨磷灰石层形成的研究

The formation of bone-like apatite on the surfaces of the bioceramics and biocomposites

钙磷生物材料表面类骨磷灰石层的形成对其植入体内诱导新骨生成起非常重要的作用。本实验采用2倍模拟体液（2×SBF）为介质，通过仿生浸泡的方法研究了羟基磷灰石（HA）陶瓷及其复合材料羟基磷灰石／聚乳酸（HA／PLA）、羟基磷灰石／聚己内脂（HA／PCL）、羟基磷灰石／丝素（HA／SF）和羟基磷灰石／壳聚糖（HA／CS）表面诱导类骨磷灰石层形成的差异。实验结果表明，HA陶瓷及其复合材料在2×SBF溶液中仿生浸泡7d后，各样品表面均有一层厚度不同的类骨磷灰石层生成。并且该类骨磷灰石层的结晶度较低，晶粒较细（15～30nm），与人体自然骨无机物的结构非常类似。其中，在这4种复合材料中，HA／CS和HA／SF复合材料中因丝素蛋白和壳聚糖富含多种功能基团，能有效促进类骨磷灰石晶体的形核和生长，因而诱导类骨磷灰石生成的能力最强，显示其良好的生物活性。

It has been well-known that the formation of bone-like apatite on the surtace ot calcium pnospnate bioceramics is important to their osteoinductivity and the growth of new bone. In the present study, the formation of bone-like apatite layer on the surface of hydroxyapatite （HA） ceramics and the biocomposites （hydroxyapa- tite/polylaetide （HA/PLA）, hydroxyapatite/polyeaprolaeton （HA/PCL）, hydroxyapatite/ehitosan （HA/CS）, hydroxyapatite/silk fibroin （HA/SF）） were investigated in detail by the biomimic immersion in duple simulated body fluid （2×SBF）. The results showed that there were the bone-like apatite layers with some extent of thickness on the surfaces of the samples after immersion in 2 × SBF for 7days, which with poor crystallinity and nano sized （15-30nm）. Moreover, the bioeomposites of HA/CS and HA/SF were benefial to inducing the formation of bone-like apatite on their surfaces, owing to many function groups in SF and CS, which benefit to nucleation and growth of bone-like apatite crystals.