仿松质骨的胶原/纳米羟基磷灰石人工骨修复兔大段骨缺损

背景:课题组自主研发一种仿松质骨生物活性纳米人工骨,在临床试验前进行系列的动物实验提供必需的技术资料。目的:评价自主研发的仿松质骨胶原/纳米羟基磷灰石人工骨的生物可降解性、骨引导性和骨诱导性。设计、时间及地点:随机对照动物实验,于2007-03-01/06-08 在广东省医学实验动物中心完成。材料:纳米羟基磷灰石粉末通过共沉淀反应合成。将纳米羟基磷灰石粉末按一定比例加入胶原溶液中充分混合,然后冷冻干燥即得块状纳米人工骨。15 只新西兰大白兔,随机分成 3 组,每组 5 只,分别为空白对照组、羟基磷灰石珊瑚组和纳米人工骨组。方法:所有动物局部麻醉后在一侧尺骨造成10 mm 全缺损,纳米人工骨组和羟基磷灰石珊瑚组分别植入纳米人工骨、羟基磷灰石珊瑚,空白对照组不植入任何物质。在植入后30,60 d,通过大体观察、X 射线摄片、电子显微镜及组织学评价该人工骨的的生物相容性和骨诱导性。主要观察指标:纳米人工骨的超微结构,创面愈合情况,人工骨降解情况和缺损区骨组织再生情况。结果:该人工骨具有与天然松质骨相似的内连孔结构、孔隙率和孔径,这种结构有利于骨细胞的长入和血管新生;植入后 30 d 可见纳米人工骨组缺损处被纳米人工骨修复,人工骨被彻底降解。植入后 60 d 羟基磷灰石珊瑚组未见骨修复和骨降解,仅见大量软组织再生。结论:自制仿松骨胶原/纳米羟基磷灰石人工骨可降解,成骨效果好,可替代自体骨移植修复大段骨缺损。

Nano-hydroxyapatite/collagen composites imitating cancellous bone for repair of massive bone defects in rabbits

BACKGROUND: A nano-artificial bone imitating cancellous bone has been developed. It is necessary to perform a series of animal experiments regarding this artificial bone prior to clinical trials for providing technical information.OBJECTIVE: To evaluate the biodegradability, osteoconductivity, and osteoinductivity of nano-hydroxyapatite/collagen (nano-HA/CO) composites imitating cancellous bone.DESIGN, TIME AND SETTING: A randomized controlled animal experiment was performed at the Guangdong Medical Laboratory Animal Center between March and June 2007.MATERIALS: The HA powder was synthesized by a co-precipitation reaction. The obtained HA powder was added into collagen solution at a certain ratio under vigorous stirring. The nano-HA/CO composites were frozen-dried to obtain nano-artificial bone. Fifteen New Zealand rabbits were randomly divided into 3 groups, with 5 rats per group: blank control, coral-HA, and nano-HA/CO.METHODS: Following local anesthesia, 10 mm bone defect was made on the right ulnas in all rabbits. HA coral and Nano-HA/CO bone composites were inserted into the defects in the HA and nano-HA/CO groups, respectively. The blank control group received no any implantation. At 30 and 60 days following surgery, biocompatibility and osteoinductivity of cancellous bone resembling nano-HA/CO bone substitute were assessed by macroscopic examination, scanning electron microscopy, X-ray photography, and histological examination after implantation in vivo.MAIN OUTCOME MEASURES: Ultrastructure and degradation condition of nano-HA/CO bone substitute, postoperative wound healing, and osteo-regeneration in defect region.RESULTS: The nano-HA/CO bone composite possessed interconnected porosity and pore size resembling cancellous bone, which benefits in-growth of osteoblasts and blood vessels. At 30 days following surgery, the nano-HA/CO group exhibited that osteoblasts spread around, and ossification occurred in almost all newly formed bone area. At 60 days following surgery, the coral-HA group showed that only connective tissue regenerated without bone tissue regeneration and degradation of grafts.CONCLUSION: This nano-HA/CO bone composite shows great promise in repairing massive bone defect in stead of autograft.