酶组织化学方法在HA/TCP体内外生物相容性评价中的初步应用

Application of Enzyme Histochemistry in Evaluation of In Vitro and In Vivo Biocompatibility of HA/TCP

通过研究材料与细胞 /组织相互作用后胞内酶活性的变化与材料生物相容性之间的关系 ,探讨酶组织化学法应用于材料生物相容性评价的可行性。结果发现 ,与 HA/ TCP和钛合金复合培养的成骨细胞形态学上无明显差异。但 HA/ TCP与兔成骨细胞复合培养初期可导致细胞 NADH、SDH、L DH和 CCO酶活性的一过性下降 ,而钛合金对复合培养细胞的酶活性没有明显影响 ,提示 HA/ TCP材料溶出物对细胞有轻微的损伤。两种材料体内植入后引起的组织学变化过程相似 ,主要表现为损伤引起的急性炎症过程。酶组织化学检测发现 ,术后 10 d内植入体周围组织四种酶活性均明显下降 ,15 - 30 d内逐渐恢复正常。但 HA/ TCP组酶活性的恢复略滞后于钛合金组 ,也表明材料溶出物对细胞有一定损伤。体内外实验均发现酶学指标能更灵敏地反映材料对细胞的作用 ,酶组织化学法可望应用于材料生物相容性评价。

In order to explore the possibility of applying enzyme histochemistry in biocompatibility evaluation,we investigated the effect of biomaterials on the activities of intracellular enzymes in this experiment. It was found that there was no obvious difference in morphology between osteoblasts co-cultured with HA/TCP and with Ti-alloy. However,transient down-regulation of NADH,SDH,LDH and CCO of the osteoblasts co-cultured with HA/TCP was detected by enzyme histochemistry. but these enzymes of osteoblasts the co-cultured with Ti-alloy were not down-regulated. It was indicated that something extracted from HA/TCP injured the co-cultured osteoblasts slightly.Similar early acute inflammatory reactions were observed after HA/TCP and Ti-alloy were separately implanted into the dorsal muscle of rabbit. There was also no obvious difference between the tissue response to HA/TCP and that to Ti-alloy. Activities of enzymes in tissues around implanted materials were down-regulated at the early injury period and recovered gradually within 30 days post-operation. But the mild toxicity of extracts from HA/TCP was demonstrated by the fact that the recovery period of HA/TCP group was longer than that of Ti-alloy group. It was proved that enzyme histochemistry is more sensitive than tissue morphology analysis in detecting the cell or tissue responses to biomaterials. Therefore,it is possible to use enzyme histochemistry in biocompatibility evaluation.