Stem cell and growth factor delivery vehicles for cartilage repair

Co-delivery of embedded growth factor-loaded microspheres and adult stem cells in a hydrogel matrix was studied for its potential as a cell-based therapeutic strategy for cartilage regeneration in partial thickness chondral defects. A photopolymerizable N-methacrylate glycol chitosan (MGC) was employed to form an in situ gel that was embedded with two formulations of growth factor-loaded microspheres and human adipose-derived stem cells (ASC). The polymeric microspheres were used as a delivery vehicle for the controlled release of growth factors to stimulate differentiation of the ASC towards the chondrocyte lineage. Bone morphogenetic protein-6 (BMP-6) and transforming growth factor-b3 (TGF-b3) were delivered at 5 ng/day at highly bioactive states. The ratio of collagen type II to I per cell was significantly higher for ASC chondrogenesis induced by the sustained release of BMP-6 and TGF-b3 in MGC gels than that of non-induced ASC or with soluble growth factor administration in the culture media. Thus, the co-delivery of growth factor-loaded microspheres and ASC in MGC gels successfully induced ASC chondrogenesis and is a promising strategy for cartilage repair.

Autorentext

Dr. Abby Sukarto obtained her B.Sc. from The University of Texas at Austin, M.Sc. from Wayne State University in Detroit and Ph.D. from Queen's University in Kingston, Canada. Her areas of expertise are developing hydrogels and polymeric microspheres as delivery vehicles for stem cells, viral/non-viral genes and proteins in osteochondral repair.