Plasma-induced customizable poly(ester-urethane) surface for cell culture platforms

This work aims to study the bio-interfacial properties of poly(ester-urethane) composite scaffolds based on poly (3-hydroxybutyrate) [PHB] and modified by surface plasma-radiation-induced graft polymerization of N-isopropylacrylamide (NIPAAm). The delivering power of the Argon radio-frequency plasma was increased from 5-20 W. The yields over the polyurethane surface, grafting density, topographical dimensions, architecture, surface energy, and wettability were surveyed in the established plasma regimes. Successful grafting of NIPAAm was verified by Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy analysis. Characterization using atomic force microscopy revealed that the surface of the scaffolds is more uniform in lower plasma delivering powers. The results show a high grafting density surface with a low degree of grafting (3-9 %). The contact angles decreased, and the surface energy rose with increasing delivering power. The surface area, total pore volumes are similar between the samples. The porosity percentage and the average pore diameter hinted at a decrease in the treated composite as compared to the pristine scaffold. Although all the composites showed to be non-toxic and highly viable (>98 %) for human dermal fibroblasts, the results showed better attachment, spreading, and growth of fibroblasts on scaffolds with moderate hydrophilicity (5 W). The in vivo experiments revealed that the plasma-treated scaffolds diminished the inflammatory infiltrate, which means an improved acceptance as compared with untreated PHB polyurethane.