Chitosan-based injectable porous microcarriers with enhanced adipogenic differentiation and angiogenesis for subcutaneous adipose tissue regeneration

Chitosan is a promising biomaterial for tissue engineering, but its functionality is limited by a lack of bioactive sites. This study develops chitosan/amniotic membrane microcarriers to enhance vascularization and tissue regeneration for subcutaneous adipose tissue. The incorporation of decellularized amniotic membrane enhances the bioactivities of chitosan in promoting cell differentiation and angiogenesis. Optimized preparation yielded porous microcarriers with a particle size of 261.2 ± 28 μm and an average pore size of 19.0 ± 4 μm. In vitro degradation analysis showed accelerated degradation with higher amniotic membrane content. Cytocompatibility and adipogenic capacity assessments indicated that the microcarriers supported cell adhesion and proliferation over 7 days, with amniotic membrane facilitating adipogenic differentiation of adipose-derived stem cells. When injected subcutaneously into nude mice, these microcarriers formed neoplastic adipose tissues, which were harvested 8 weeks later. Fluorescence staining, oil-red O staining and CD31 labeling demonstrated that amniotic membrane incorporation significantly enhanced in vivo adipose tissue formation and angiogenesis.