(770e) Plasma Polymerization of Thermoresponsive Poly(N-isopropyl acrylamide) for the Release of Multiple Cell Types

Poly(N-isopropyl acrylamide) (pNIPAM) undergoes a sharp property change in response to a moderate temperature drop around physiological temperatures. This behavior has generated great interest in the biomaterials community, and pNIPAM has already been used to harvest intact cell sheets for cell sheet engineering applications. Currently, many techniques are used to deposit pNIPAM, including electron beam irradiation and solution deposition of silanes and self-assembled monomers. Our research uses plasma polymerization of NIPAM from the vapor phase (ppNIPAM), a sterile, solvent-free method that is compatible with surfaces of any geometry or chemistry, making it extremely useful for cell and tissue culture. Following their characterization (e.g., using X-ray photoelectron spectroscopy for surface chemistry, interferometry for film thickness, contact angles for thermoresponse), ppNIPAM-derivatized substrates were used to culture multiple cell types, including bacterial (Halomonas marina), yeast (Saccharomyces cerevisiae), and mammalian (bovine aortic endothelial) cells. We find that each of these cell types adhere to pNIPAM above its LCST, including yeast, which are not normally adherent to culture substrates. Furthermore, we find that each of the cell types is released from pNIPAM, although the method of release may differ (i.e., detachment of sheets vs. release of isolated cells). These findings indicate that the ability of pNIPAM to reversibly adhere cells has many other applications for the study of cell/surface interactions, in addition to its well-established use for cell sheet engineering.