Porous gelatin-based phosphorylated scaffold: Microstructure, cell response and osteogenic differentiation of human adipose-derived mesenchymal stem cells

To repair the highly organized composite bone tissue, the design and development of biomimetic threedimensional scaffolds is an active strategy. Here, we describe the fabrication route of a bioengineered gelatinbased scaffold for potential application in bone tissue engineering. First, phosphorus-containing polyurethane (PU-P) polymer was synthesized by polymerization starting from phosphorous polyol and methylene diisocyanate (DMI). Second, a gelatin/phosphorus-containing polyurethane (Gelatin/PU-P) scaffold was prepared by solution mixing, ultrasonication, and freeze-drying of gelatin and PU-P polymer. Next, prepared scaffold samples were characterized by FT-IR, SEM microscopy, porosity measurement, swelling, degradability, and mechanical tests. The scaffold with a porosity of about 78 % was achieved, and at the same time, it had good dimensional stability so that it only lost 43.61 % of its initial weight after 35 days immersing in PBS. Moreover, Gelatin/PU-P showed flexibility, large elongations at break (420 %) and high tensile strength (14 MPa). Finally, biological assessments revealed that the scaffold significantly supported the viability of Adipose-derived mesenchymal stem cells (ADMS). High ALP activity, enhancement in mineralization, and greater expression of osteogenic gene markers in cells grown on the Gelatin/PU-P confirmed the osteoinductivity of the scaffold. These findings suggested that Gelatin/PU-P can be used as a bioactive scaffold for bone tissue engineering.