Entangled Titanium Fibre Balls Combined with Nano Strontium Hydroxyapatite in Repairing Bone Defects

OBJECTIVE: To investigate the effect of entangled titanium fibre balls (ETFBs) combined with nano strontium hydroxyapatite (nano-Sr-HAP) on the repair of bone defects in vivo. MATERIALS AND METHODS: Twenty-four 6-month-old, specific pathogen-free, male Sprague-Dawley rats were used. Drill defects were created in bilateral femoral condyles. ETFBs combined with nano-Sr-HAP were selected randomly from 72 samples and implanted into the femoral bone defects of left legs, which served as the experimental group, while ETFBs without nano-Sr-HAP were implanted into right legs for comparison. The bone defects on both sides were X-rayed. The anteroposterior positions and histological procedures and evaluations of each sample were performed at 1, 2, 4 and 8 weeks post-surgery. RESULTS: Histological results showed that the ETBs allowed new bone to grow within their structure. Additionally, an increase in new bone was seen on the nano-Sr-HAP side compared to the control side. The results of histomorphometric analysis confirmed that the new bone formation on the left side gradually increased with time. There was a statistical increase in new bone at 2, 4 and 8 weeks, and the differences between the two sides were statistically significant at weeks 4 and 8 (p < 0.05 for all comparisons). CONCLUSION: The results showed that ETFBs possess a unique 3-dimensional interconnective porous structure and have excellent biocompatibility, cell affinity and osteoconductivity, which makes them useful as scaffold materials for repairing bone defects. On the other hand, nano-Sr-HAP improved the bone defect-repairing capacity of the ETFBs, which showed osteoinductive properties.