The coencapsulation of growth factor-loaded microspheres with
adipose-derived stem cells (ASCs) within a hydrogel matrix was studied
as a potential means to enhance ASC chondrogenesis in the development of
a cell-based therapeutic strategy for the regeneration of partial
thickness chondral defects. A photopolymerizable N-methacrylate
glycol chitosan (MGC) was employed to form an in situ gel used to
encapsulate microspheres loaded with bone morphogenetic protein 6
(BMP-6) and transforming growth factor-β3 (TGF-β3) with human ASCs. ASC
viability and retention were enhanced when the Young’s modulus of the
MGC ranged between 225 and 380 kPa. Grafting an RGD-containing peptide
onto the MGC backbone (RGD-MGC) improved ASC viability within the gels.
The effects of BMP-6 and TGF-β3 released from the polymer microspheres
on ASC chondrogenesis were also assessed.