Cell adhesion and proliferation studies on semi-interpenetrating polymeric networks (semi-IPNs) of polyacrylamide and gelatin.

In this study, the effect of feed composition, degree of hydrophilicity, and internal morphology has been investigated for cell proliferation potential of the polyacrylamide/gelatin (PAm/G) semi-interpenetrating polymeric network (semi-IPNs). Polycaprolactone diacrylate was used to cross-link polyacrylamide chains. Scanning electron microscopy (SEM) micrographs demonstrate uniformly distributed porous structure with internal diameter in the range of 75-175 μm, dependent on matrix compositions. Water-air contact angle was found in the range of 49° ± 0.22 to 89° ± 0.14 (p < 0.02) suggesting varying degree of hydrophilicity of the hydrogel surface. In addition, protein adsorption study showed 45 ± 0.14 μg to 64 ± 0.12 μg (p < 0.01) of protein adsorbed per cm² of hydrogel. Quantitative estimation of cell adhesion and proliferation was carried out by DNA quantification using fluorimetric assay method (p < 0.02). Microscopic images of proliferative cells on semi-IPNs by fluorescent and inverted phase contrast supported the findings of DNA quantification. Contact angle in the range of 63-69° in association with 52-59 μg/cm² protein absorption and 115-150 μm pore size was found optimum for fibroblast proliferation on PAm/G semi-IPN scaffolds. The newly developed semi-interpenetrating network may serve as a potential scaffold for soft tissue-engineering applications.