Electrosensitive polyacrylic acid/fibrin hydrogel facilitates cell seeding and alignment.

Three-dimensional cell culture and conditioning is an effective means to guide cell distribution and patterning for tissue engineered constructs such as vascular grafts. Polyacrylic acid is known as an electroresponsive polymer, capable of transforming environmental stimuli like electrical energy to mechanical forces. In this study, we developed an electrosensitive and biocompatible hydrogel-based smart device composed of acrylic acid and fibrin as a tissue engineered construct to mechanically stimulate cells. Structural properties of the hydrogel were assessed by FTIR-ATR, scanning electron microscopy, prosimetry, and swelling measurement. Distribution and alignment of porcine smooth muscle cells (pSMCs) seeded on the surface of lyophilized hydrogels were evaluated and quantified by two-photon laser scanning microscopy. Smooth muscle cell tissue constructs exposed to 2 h of pulsatile electrical stimulation showed significantly enhanced cell penetration and alignment due to dynamic changes produced by alternative swelling and deswelling, in comparison with static samples. On the basis of the results, this hydrogel under electrical stimulation works as a mechanical pump, which can direct SMC alignment and facilitate infiltration and distribution of cells throughout the structure.