In vivo animal study on osteal histocompatibility of carbon fiber-reinforced nano-hydroxyapatite/polyamide 66 composites / 中国组织工程研究

ABSTRACT

BACKGROUND:Compared with hydroxyapatite materials and other nano-hydroxyapatite composites, carbon fiber-reinforced nano-hydroxyapatite/polyamide 66 composites have been significantly improved in the mechanical strength, toughness, elastic modulus and other aspects. It can be used for repairing bone defects of loading parts. OBJECTIVE:To investigate the biocompatibility of carbon fiber-reinforced nano-hydroxyapatite/polyamide 66 composites in bone tissues. METHODS:Eight Bama mini pigs were taken to establish models of thoracic vertebral defects and implanted with carbon fiber-reinforced nano-hydroxyapatite/polyamide 66 composites. At 8, 16 and 24 weeks after implantation,the animals were sacrificed, respectively, for bone mineral density detection and hematoxylin-eosin staining. Blood samples for kidney and liver function tests were taken before and 1 and 8 weeks after implantation. RESULTS AND CONCLUSION: Hematoxylin-eosin staining of bone samples showed that the materials could bond with the bone defect interface without rejection, and could induce osteogenesis of chondrocytes. At 8 weeks after surgery, the broken ends of cancelous bone closed and the composite material was wrapped by granulation tissues. At 16 weeks after surgery, granulation tissues were organized and new bone developed directly from fibroblast cels. The new bone tissues were nearly fused with the end of cancelous bone. At 24 weeks after surgery, new bone tissue became mature lamelar bone, and the end of cancelous bone was connected tightly with the composite material. Bone mineral density of the implanted vertebra showed an increase trend at 8, 16 and 24 weeks after implantation. Over time, the bone mass was increased. The liver and kidney function tests showed that there was no significant difference before and after implantation. It is preliminarily believed that the carbon fiber-reinforced nano-hydroxyapatite/polyamide 66 composite has excelent histocompatibility and bioactivity without hepatic toxicity and nephritic toxicity.