In vivo efficacy and toxicity of synthesized nano-β-tricalcium phosphate in a rabbit tibial defect model:

Previous studies of the biocompatibility of β-tricalcium phosphate (β-TCP) focused on bulk-sized β-TCP, and little is known about the biocompatibility of nano β-TCP particles (nβ-TCP). The objectives of this study were to synthesize nβ-TCP particles and determine their efficacy in a rabbit tibial defect model. The nβ-TCP particles were first synthesized using a wet chemical precipitation process. The particles were then implanted in the left tibia of New Zealand white rabbits, and the defect site healing was evaluated for a period of 16 weeks using radiography, computed tomography, and histology. Data were compared with those of a sham (empty) control. Results showed that the defect site treated with nβ-TCP particles did not heal completely after 16 weeks, whereas full cortical bone recovery was observed in the sham control group of rabbits. Histopathological examination showed that the nβ-TCP particles caused an excessive and prolonged inflammatory response by the host. The nano-scaled size and biodegrad...