Effect of nHA/CS/PLGA delivering adipose stem cell-derived exosomes and bone marrow stem cells on bone healing—in vitro and in vivo studies

Adipose stem cell-derived exosomes (ADSC-EXO) have been demonstrated to promote osteogenic differentiation of bone marrow stem cells (BMSCs) and facilitate bone regeneration. The present study aims to investigate the effect of ADSC-EXO-loaded nano-hydroxyapatite/chitosan/poly-lactide-co-glycolide (nHA/CS/PLGA) scaffolds on maxillofacial bone regeneration using tissue engineering. ADSC-EXO was isolated and co-cultured with BMSCs, and the osteogenic differentiation of BMSCs was assessed through the detection of mineralized nodule formation, alkaline phosphatase (ALP) activity, and mRNA expression of COL1A1 and runt-related transcription factor 2 (RUNX2). The nHA/CS/PLGA scaffolds were fabricated and loaded with ADSC-EXO and BMSCs, and these tissue engineering complexes were applied to the maxillofacial bone defect region of rabbits to elucidate their bone regeneration effect. The osteogenic differentiation of BMSCs was markedly enhanced when they were co-cultured with ADSC-EXO. This was evidenced by an increase in the formation of mineralized nodule formation, ALP activity, and mRNA expression of COL1A1 and runt-related transcription factor 2 (RUNX2). In vivo experiments demonstrated that the application of ADSC-EXO and BMSCs loaded nHA/CS/PLGA scaffolds effectively repaired maxillofacial bone defects in rabbits. ADSC-EXO has been demonstrated to promote the osteogenic differentiation of BMSCs. The ADSC-EXO and BMSCs loaded nHA/CS/PLGA scaffolds have been shown to facilitate the regeneration of maxillofacial bone defects. This may serve as a potential therapeutic strategy for large-scale bone defects.