RESUMEN
Objective To explore the effect of nano-hydroxyapatite/collagen scaffolds incorporating ADM-PLGA microspheres in repairing large bone defects of rabbit femoral condyle. Methods Animal models of bone defects were induced in 21 New Zealand white rabbits by drilling holes in bilateral femoral lateral condyles , and the rabbits were equally divided into 3 groups:group A as the control group with the defects untreated , group B treated by filling with nano-hydroxyapatite/collagen scaffolds (NHAC), and group C treated by filling with the nano-hydroxyapatite/collagen scaffolds incorporating ADM-PLGA microspheres (ADM-PLGA-NHAC). At week 12 after implanting , the rabbits were all sacrificed for the implanted scaffolds , which were then examined by X-ray , and Micro-CT 3D reconstruction and in histology for evaluation of the new bone formation. Results X-ray, Micro-CT and the measurement and analysis of BMD indicated thatthere was no significant differencein the new bone formation between group B and group C (P > 0.05). The histological examination revealed that. 12 weeks after operation an evident number of new born bones were seen on the implanted scaffolds in groups B and C , while very few were seen scattering in group A. Conclusion The nano-hydroxyapatite/collagen scaffolds incorporating ADM-PLGA microspheres is effective in repairing bone defect without influencing the prosthetic process.