掺锶冻干骨体内植入的生物相容性

Biocompatibility of in vivo implanted strontium incorporated frozen dried bone

背景:同种异体冻干骨是良好的骨移植材料,但在制备过程,其天然活性成分有所丢失或部分失活,成骨活性下降。努力改善冻干骨成骨活性,希望研制出一种能克服上述缺点的新型材料运用于临床。目的:观察掺锶冻干骨植入大鼠体内的生物学活性。方法:按照标准的冻干骨加工程序制备大鼠股骨髁冻干骨材料,采用氯化锶溶液浸泡方法制备掺锶冻干骨。将27只健康成年SD大鼠随机分为3组,每组9只。SD大鼠钝性分离肌肉,造成股部肌袋,双侧均行手术。植入掺锶冻干骨作为实验组,同法植入未掺锶的普通冻干骨作为对照组。空白对照组双侧均不植入任何材料。分别于植入后4,8,12周处死各组动物3只,行大体观察、组织学观察,并依据炎性浸润及组织纤维化程度进行组织学评分。结果与结论:采用氯化锶溶液浸泡方法制作掺锶冻干骨,锶相对钙元素掺入摩尔浓度为4.2%时在骨质内层锶元素浓度分布比较均匀。实验组和对照组植入材料周围均可见炎性细胞、肉芽组织和血管生成,并随着时间推移,炎性浸润程度明显降低,而周围纤维组织包绕增加。空白对照组炎性浸润程度轻,少量组织纤维化。实验组和对照组与空白对照组相比,炎性浸润程度及组织纤维化程度组织学评分差异有显著性意义(P<0.05)。说明通过温和的锶-钙离子交换方法可以在冻干骨中有效的掺入锶元素,获得一种掺锶冻干骨材料;该掺锶冻干骨具有良好的生物组织相容性,与普通冻干骨比较无明显差异。

BACKGROUND：Frozen dried bone allograft is a good material of bone transplantation.But in the preparation procedure,some part of natural activity will be lost and osteogenic activity descent.To improve osteogenic activity of frozen dried bone,new materials are hoped to invent and used in clinic.OBJECTIVE：To evaluate biocompatibility of strontium incorporated frozen dried bone in vivo.METHODS：The rat frozen dried bone was prepared according to a standard procedure,then the bone was immersed into strontium chloride to prepare the rat strontium incorporated frozen dried bone.Totally 27 healthy adult SD rats were randomly assigned to 3 groups.Rats were prepared for thigh muscle pouches models,and left and right sides were both operated.Strontium incorporated frozen dried and normal frozen dried bones were transplanted into thigh muscle pouches as experimental and control,respectively.The both sides of thigh muscle pouches without implant served as blank control.Three rats were sacrificed from each group at 4,8 and 12 weeks after operation to undergo gross,histological observation,and the inflammatory infiltration and fibrosis were scored.RESULTS AND CONCLUSION：Strontium concentration in frozen dried bone achieved 4.2% through soaking method treatment.Inside the bone,strontium concentration was even.The inflammatory infiltration and granulation tissues and angiogenesis were seen in the experimental and control groups.The inflammatory infiltration was alleviated gradually with time prolonged and the surrounding fibrous tissues increased.Inflammatory reactions in the blank control group were alleviated gradually and less fibrosis.The scores of inflammatory infiltration and fibrosis of the experimental and control groups were significant different from that of the blank control group（P 0.05）.Strontium incorporated frozen dried bone can be made by ion-exchange method,which has good biocompatibility similar to normal frozen dried bone.