ABSTRACT
BACKGROUND:As a bone reconstruction material, nano-hydroxyapatite has good biocompatibility and osteoconduction, but the clinical use of nano-hydroxyapatite alone stil has many deficiencies. OBJECTIVE:To explore the in vivo osteogenic capability of nano-hydroxyapatite/ polyamide composites. METHODS: Twenty-four New Zealand white rabbits were subjected to humeral head replacement using nano-hydroxyapatite/polyamide composite material. X-ray observation and histological observation were done at 3, 6, 12, 24 weeks after replacement. RESULTS AND CONCLUSION: (1) X-ray observation: No thinned cortical bone and ectopic ossification occurred on the upper end of the composite material at different time, and the nano-hydroxyapatite/polyamide material had no signs of fragmentation. The cortical bone around the composite material was fuzzy, and the bone mineral density was increased with time. (2) Histological observation: At 3 weeks after replacement, a large number of cels could be visible, including mesenchymal stem cels and mononuclear macrophages. At 6 weeks after replacement, a large amount of fibrous tissues, fibroblasts and mononuclear macrophages stil existed in the boundary membrane, but chondrocytes and osteoblasts distributed less. At 12 weeks after replacement, a wide range of original trabecular bone began to form and were mostly flat that arranged regularly. At 24 weeks after replacement, the boundary membrane was ful of bone cels, but the cels on the surface of trabecular bone were relatively regular and primitive cels in the bone tissue began to transform into the lamelar bone. These findings indicate that the nano-hydroxyapatite/polyamide material has good osteogenic capability.
