Biomimetic scaffolds facilitate healing of critical-sized segmental mandibular defects

Objective To investigate the efficacy of biomimetic PLGA scaffolds, alone and in combination with bone morphogenic protein (BMP-2) and adipose-derived stem cells (ASCs), to heal a critical-sized segmental mandibular defect in a rat model. Study design Prospective animal study. Methods ASCs were isolated and cultured from the inguinal fat of Lewis rat pups. Using three-dimensional printing, PLGA scaffolds were fabricated and impregnated with BMP-2 and/or ASCs. Critical-sized 5-mm segmental mandibular defects were created in adult Lewis rats and implanted with (1) blank PLGA scaffolds, (2) PLGA scaffolds with ASCs, (3) PLGA scaffolds with BMP, or (4) PLGA scaffolds with BMP and ASCs. Animals were sacrificed at 12 weeks. Bone regeneration was assessed using microCT, and graded on a semi-quantitative bone formation and bone union scale. Results Twenty-eight rats underwent creation of segmental mandibular defects with implantation of scaffolds. Nine rats suffered complications and were excluded from analysis, leaving 19 animals for inclusion in the study. MicroCT analysis demonstrated no bridging of the segmental bony defect in rats implanted with blank scaffolds (median bone union score = 0). Rats implanted with scaffolds containing BMP-2 (median bone union = 2.0), ASCs (median bone union = 1.5), and combination of BMP and ASCs (median bone union = 1.0) demonstrated healing of critical-sized segmental mandibular defects. Bone regeneration was most robust in the BMP-2 treated scaffolds. Conclusions The current study utilizes a novel animal model to study the efficacy of biomimetic scaffolds carrying osteogenic factors to induce healing of a critical-sized segmental mandibular defect. Level of evidence N/A, Basic Science Animal Research.