| AVS 55th International Symposium & Exhibition | |
| Biomaterial Interfaces | Tuesday Sessions |
| Session BI-TuP |
| Session: | Biomaterials Interfaces Poster Session with Focus on Cells and Proteins at Interfaces |
| Presenter: | J.A. Reed, University of New Mexico |
| Authors: | J.A. Reed, University of New Mexico M. Bore, University of New Mexico L.K. Ista, University of New Mexico G.P. Lopez, University of New Mexico H.E. Canavan, University of New Mexico |
| Correspondent: | Click to Email |
Poly(N-isopropyl acrylamide), or pNIPAM, is a smart polymer that is of great interest in the bioengineering community. Above its lower critical solution temperature (LCST), the polymer is relatively hydrophobic, and mammalian cells grown on pNIPAM-grafted surfaces act in a similar fashion as those grown on typical tissue culture polystyrene (TCPS): they proliferate into a confluent sheet. Below the LCST (i.e., room temperature) the polymer physically changes, becoming hydrophilic and swelling. Furthermore, when the temperature of the cell culture is dropped below the LCST of the polymer, the cells will detach and can be harvested for tissue engineering applications. This is in contrast to cells grown on TCPS alone, which will not detach using a temperature drop, instead requiring enzymatic digestion (via trypsin) or mechanical scraping to remove them. In this work, we present a novel, solution-based technique to generate pNIPAM surfaces from pNIPAM and tetraethyl orthosilicate (spNIPAM). The composition of the films (i.e., weight % of pNIPAM) was optimized for reversible cell adhesion by observing the thermoresponse, surface chemistry, and cell release characteristics. Characterization of the surface chemistry of the spNIPAM substrates was done using X-ray photoelectron spectroscopy (XPS), interferometry, and contact angle measurements). Characterization of the cell-releasing behavior of the spNIPAM substrates was determined by observing the ability of surfaces to release confluent bovine aortic endothelial cells (BAECs). From these results, we conclude that the fastest, most reliable release of BAECs occurred on surfaces spin coated with a solution of .35wt% pNIPAM/TEOS.