Promoting the cytocompatibility of polyurethane scaffolds via surface photo-grafting polymerization of acrylamide

Polyurethane (PU) porous scaffolds were modified by grafting polymerization of acrylamide (AAm) initiated under UV light. A pre-adsorbing-monomer method was used beforehand. FTIR-ATR spectroscopy and X-ray photoelectron spectroscopy (XPS) measurements confirmed the presence of grafted PAAm on PU scaffolds. The measurement of water adsorption demonstrated the improvement of hydrophilicity after PU scaffolds were grafted with polyacrylamide (PAAm). The PAAm grafting degree related to the amount of AAm adsorbed, average pore diameter, and the degree of porosity. This study shows that higher degree of porosity and bigger porous areas yielded larger amounts of absorbed AAm and higher grafting degrees. In vitro human endothelial cell cultures of PU scaffolds modified with hydrophilic PAAm showed better cytocompatibility than the control matrix.