A novel gelatin-based micro-cavitary hydrogel for potential application in delivery of anchorage dependent cells: A study with vasculogenesis model.

Hydrogels have been widely regarded as promising tissue engineering scaffolds and cell delivery vehicles, however, their inherent submicron- or nano-scale polymer networks severely inhibit the settlement of anchorage dependent cells (ADCs). Here, using endothelial progenitor outgrowth cells (EPOCs) as the typical ADCs, a gelatin-based micro-cavitary gel (namely Gel-MCG) is developed with gelatin-methacrylate and gelatin microspheres as precursor and porogens, respectively, to promote cellular focal adhesion and functions. The introduction of micro-cavitary structures within the Gel-MCG improves its physical properties as well as creates numerous gel-microcavity interfaces within gel-based matrices. Compared with conventional gelatin gel (Gel-G) scaffold, the Gel-MCG provides more suitable microenvironments for EPOCs' attachment, spreading, and proliferation, and then which leads to enhanced endothelial differentiation and vascularization as demonstrated by higher expressions of endothelial markers. The Gel-MCG system shows great potential as vehicle for the delivery of ADCs in tissue engineering.