The use of poly(L-lactic-co-glycolic acid)/tricalcium phosphate as a bone substitute in rabbit femur defects model

Autogenous bone grafting is still the gold standard for use in bone defects in orthopedic, plastic, and craniofacial surgeries. However, some patients are unable to provide sufficient quantity of bone and the high postoperative morbidity limits its clinical use. Currently, various bone substitutes are available for clinical applications, including calcium phosphate and biodegradable polyester. But hydroxyapatite is considered nondegradable and the degradation rate of biodegradable polyester is too fast, therefore both these biomaterials are hardly used clinically. To resolve this problem, we fabricated a biodegradable porous bone substitute by merging poly(L-lactic-co-glycolic acid) (PLGA) and β-tricalcium phosphate (TCP), such that the new bone substitute could provide the advantages of both the materials. The New Zealand white rabbit femur defect model was used to assess the biocompatibility and degree of osteoconduction of this new bone substitute. There was no inflammatory reaction at the PLGA/TCP grafting site based on our macroscopic observations. Three months after grafting, the cavity and central portion of the created defect within the rabbit femur was filled with newly formed bone. Furthermore, the new ingrown bone tissues readily matured to secondary bone with Haversian systems similar to the surrounding cancellous bone. We conclude that the newly fabricated PLGA/TCP shows both excellent biocompatibility and effective osteoconduction.