可注射骨修复材料的骨组织反应评价

摘要

Objective To assess in vivo bone tissue response to an injectable bone substitute after implantation using a rab‐bit model.Methods Twenty‐five male New Zealand white rabbits were used as experimental animals.The unsaturated polypho‐sphoester/β‐tricalcium phosphate composite(UPPE/β‐TCP)and UPPE/β‐TCP composite containing 1% tetracycline(UPPE/β‐TCP/TTC)were injected in circular defects as created in the femoral condyles of rabbits and were left in place for 2 ,4 ,8 ,12 and 24 weeks.The specimens were evaluated morphologically (histology and histomorphometry )and absorption rate of implant at different time points was compared.Single factor analysis of variance and Tukey’s multiple comparison tests were used to deter‐mine statistical significance of results.Results At different implantation stages ,gross examination of retrieved implant/bone composite samples indicated that the UPPE/β‐TCP composite and UPPE/β‐TCP/TTC composite did not evoke inflammatory response ,necrosis or fibrous encapsulation in surrounding bony tissues.Histological examination revealed excellent composite/host bone bonding.At 4 weeks ,resorption induced voids between terminals of bone defects and implants were largely filled with new bone.Composite resorption ,new blood vessels ,osteocytes ,osteons and osteoblast‐like cells lining up with active new bone were observed at remodeling sites.At 12 weeks ,a new bone network was developed within femoral defect ,while composite be‐came islands incorporated in the new bone.At 24 weeks ,bone ingrowth and remodeling activities became so extensive that the interface between residual cement and new bone became less identifiable.In general ,the resorption ratio values increased with implantation time.Conclusion These results showed that UPPE/β‐TCP composite holds promise for use as a synthetic biode‐gradable scaffolds for tissue engineering.%目的：研究自制的可注射骨修复材料植入兔股骨缺损区后的骨组织反应特点。方法选用25只新西兰大白兔，在其双侧股骨内髁制作标准骨缺损区模型，分别注射不饱和聚磷酸酯／β‐磷酸三钙复合物（UPPE／β‐TCP）和添加1％四环素的UPPE／β‐TCP复合物（UPPE／β‐TCP／TTC），按2、4、8、12、24周的植入期分为5组，对骨组织样本进行组织病理学和形态学观察，并比较各期植入体的吸收率。结果在各植入期内，UPPE／β‐TCP和UPPE／β‐TCP／TTC两种复合物的骨组织反应基本一致。植入2周时，所有材料和周围骨组织均未发生明显的吸收或改建，植入体未引起周围骨组织的炎性反应和坏死；4周时植入体与骨缺损区结合良好，无纤维结缔组织囊形成，在材料发生吸收而改建的区域，可见成骨细胞、新生血管和活跃的新骨形成；8周时大部分植入体仍存在于骨缺损区内，部分植入体成为“独岛”被完全整合进入新生的骨组织中；12周时骨组织有广泛的重建；24周时植入体主体部分消失，骨组织内的生长和改建更加活跃，新生骨和骨髓样组织中可见大量材料碎片，并可见成骨样细胞。2种复合物植入骨缺损区后的吸收率均随植入时间的延长而逐渐增加，在8周以前其吸收率相似（P＞0.05），而12周时UPPE／β‐TCP／TTC复合物组的吸收率高于UPPE／β‐TCP复合物（P＜0.05），24周时2种复合物的吸收率均在60％以上。结论可注射骨修复材料UPPE／β‐TCP复合物在动物体内具有良好的骨组织生物相容性、生物可降解性和体内骨引导性，可作为修复骨缺损的新型复合材料。