Characterization and cytocompatibility of hybrid aminosilane-agarose hydrogel scaffolds

Agarose hydrogels containing aminopropyl triethoxy silane (APTS) have been prepared and evaluated as scaffolds for adhesion and proliferation of human mesenchymal stem cells (hMSCs). The preparation of the hydrogels involved the conventional melting of agarose in water followed by addition of APTS as functional group carrier. The resulting hydrogel supports have been studied by Fourier transformed infrared spectroscopy in order to get an insight into the hybrid molecular structure. X-ray photoelectron spectroscopy has been used for the analysis of the surface chemical composition of the hydrogels. It is deduced from these data that the resulting hybrid structure presents two phases with a clear tendency toward APTS surface segregation. Moreover, the observation of the desiccated hydrogel surfaces by atomic force microscopy shows that the films acquire a filament-mesh structure for increasing APTS content, while the pure agarose supports exhibit a granular structure. As a result of such a structure, the hydrogel surfaces show a hydrophobic behavior, as determined by water contact angle measurements. The biocompatibility of such platforms is supported by adhesion-proliferation assays performed with hMSCs. It is concluded that although adhesion is lower on APTS rich scaffolds, the proliferation rate on these surfaces is higher so that total number of proliferating cells does not significantly depend on APTS content in the hydrogels.