Tailoring the Microenvironment of Cells Towards Osteogenic Differentiation Using Multilayers of Glycosaminoglycans and Growth Factor Immobilization

The extracellular matrix (ECM) provides the structural support and signals important for cell fate, tissue homeostasis and regeneration. Layer-by-Layer technique can apply ECM components like glycosaminoglycans (GAGs) and proteins due to their intrinsic charge to make ECM-like multilayers. Here, the effect of microenvironment on controlling human adipose-derived stem cells’ (hADSCs) behavior was studied using multilayers composed of native GAGs (nGAGs) such as, hyaluronic acid (HA) and chondroitin sulfate (CS) or their oxidized forms “oGAGs” (oHA & oCS) in combination with collagen I; based primarily on ion pairing and on additional intrinsic covalent cross-linking by imine bond formation. Osteogenic differentiation of hADSCs was found to be stronger, when collagen I was combined with CS and in case of intrinsic cross-linking using oCS. While these studies still required osteogenic media to achieve differentiation, the second part of this study was conducted using heparin (H) and CS that were combined with chitosan as polycation. oH and oCS permitted not only intrinsic cross-linking to enhance the multilayer stability, but also controlled the release of the osteogenic growth factor BMP-2. There, the oGAGs systems were superior to nGAGs in controlling osteogenic differentiation of C2C12 muscle cells. Overall, multilayers made of oxidized CS with either collagen I or chitosan as polycations, seem to be useful to direct cell differentiation towards osteogenic and other lineages