Cheng Xiaofei, Zou Dewei, Wu Jigong, Ma Huasong, Tuo Xinlin, Wang Xiaogong, Kan Guanghan
Department of Orthopaedics, 306 Hospital, Spinal Surgery Center of PLA, Beijing, 100101, PR China.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2009 Jun;23(6):670-6.
To explore the histological and the hematological change of rabbits after implanting novel injectable artificial nucleus prostheses, and to evaluate the biological safety.
In accordance with Biological Evaluation of Medical Devices, materials of polyurethane, silicone rubber and macromolecular polyethylene for medical use were made into short column 1 cm in length and 0.3 cm in diameter. Forty-eight SPF New Zealand white rabbits weighing 2.5-3.0 kg were used, and cavity 1 cm in depth was made in the area 2 cm away from the spinal midline by separating muscle. Then according to different material being implanted, the rabbits were divided into 3 groups (n = 16): Group A, polyurethane; group B, silicone rubber; group C, macromolecular polyethylene for medical use as negative control. General condition of the rabbits was observed after operation. Gross and histology observation were conducted 1, 4, 12 and 26 weeks after operation. Blood routine, biochemical function and electrolyte assays were performed 26 weeks after operation to observe pathological changes of organs. Meanwhile, physicochemical properties of the materials were detected, and the material in the same batch was used as negative control.
All rabbits survived until the end of experiment, and all wounds healed by first intention. In each group, red swollen muscles were observed 1 week after operation and disappeared 4 weeks after operation, connective tissue around the implanted materials occurred 12 and 26 weeks after operation. At 26 weeks after operation, there were no significant differences among three groups in blood routine, biochemical function and electrolyte assays (P > 0.05). Organs had smooth surface without ulceration, ecchymosis, obvious swelling, hyperemia or bleeding, and nodules. There were no significant differences among three groups in percentage weight of each organ (P > 0.05). Histology observation: granulation tissue proliferation and inflammatory cell infiltration were observed in each group 1 week after operation, fibrous capsule formation around the materials and the disappearance of inflammatory cell infiltration were evident 4 weeks after operation, cyst wall grew over time and achieved stability 12 weeks after operation. The inflammatory response and the fiber cyst cavity of groups A and B met the standard of GB/T 16175 and were in line with group C. No specific pathological changes were discovered in the organs 26 weeks after operation. For group A, no significant difference was evident between before and after material implantation in terms of weight average molecular weight, number average molecular weight, tensile strength at break and elongation at break (P > 0.05). For group B, no significant difference was evident between before and after material implantation in shore hardness (P > 0.05).
Novel injectable nucleus pulposus prostheses do not damage local tissue and function of organs, but provide good biocompatibility and biological safety.
探讨新型可注射人工髓核假体植入家兔后的组织学及血液学变化，并评估其生物安全性。
按照医疗器械生物学评价要求，将医用聚氨酯、硅橡胶及高分子聚乙烯材料制成长度为1 cm、直径为0.3 cm的短柱体。选用48只体重2.5 - 3.0 kg的SPF级新西兰白兔，通过分离肌肉在距脊柱中线2 cm处制备1 cm深的腔隙。然后根据植入材料不同将家兔分为3组（n = 16）：A组，聚氨酯；B组，硅橡胶；C组，医用高分子聚乙烯作为阴性对照。术后观察家兔一般情况。分别于术后1、4、12及26周进行大体及组织学观察。术后第26周进行血常规、生化功能及电解质检测，观察各脏器病理变化。同时检测材料的理化性能，并以同批次材料作为阴性对照。
所有家兔均存活至实验结束，所有伤口均一期愈合。每组术后1周可见植入部位肌肉红肿，术后4周消失，术后12周及26周可见植入材料周围有结缔组织形成。术后26周，三组血常规、生化功能及电解质检测结果差异均无统计学意义（P > 0.05）。各脏器表面光滑，无溃疡、瘀斑、明显肿胀、充血或出血及结节。三组各脏器重量百分比差异无统计学意义（P > 0.05）。组织学观察：术后1周每组均可见肉芽组织增生及炎性细胞浸润，术后4周材料周围形成纤维囊，炎性细胞浸润消失，术后12周囊壁随时间生长并趋于稳定。A、B组的炎症反应及纤维囊腔符合GB/T 16175标准，与C组一致。术后26周各脏器未发现特异性病理改变。A组材料植入前后重均分子量、数均分子量、断裂拉伸强度及断裂伸长率差异无统计学意义（P > 0.05）。B组材料植入前后邵氏硬度差异无统计学意义（P > 0.05）。
新型可注射髓核假体未对局部组织及脏器功能造成损害，具有良好的生物相容性及生物安全性。
