AVS 64th International Symposium & Exhibition
    Biomaterial Interfaces Division Wednesday Sessions
       Session BI+AS-WeA

Paper BI+AS-WeA11
Investigating the Cytotoxicity of Commercially Available Poly(N-isopropyl Acrylamide)-coated Surfaces

Wednesday, November 1, 2017, 5:40 pm, Room 12

Session: In Honor of Dave Castner's 65th Birthday: Multitechnique Bio-Surface Characterization II
Presenter: Heather Canavan, University of New Mexico
Authors: L. Stapleton, University of New Mexico
M.A. Cooperstein, University of New Mexico
P.A.H. Nguyen, University of New Mexico
H.E. Canavan, University of New Mexico
Correspondent: Click to Email
Poly (N-isopropyl acrylamide) (pNIPAM) is a thermoresponsive polymer that undergoes a phase change at a physiologically relevant temperature range, which leads to mammalian cell release. Below its lower critical solution temperature (LCST ~32° C), pNIPAM becomes hydrated and is hydrophilic. In this state, its chains become extended and cells detach as intact cell sheets. Before the detached cell sheets can be used on humans, the cytotoxicity of the surfaces must be accessed. In previous studies, we found that although most techniques for polymerizing NIPAM (e.g., plasma polymerization, ppNIPAM; and sol-gel preparations of NIPAM, spNIPAM) yielded biocompatible films, those from commercially available NIPAM (cpNIPAM) were relatively cytotoxic. In this work, we investigate the reasons behind this anomaly. The cpNIPAM-coated surfaces were evaluated for their thermoresponse and surface chemistry using standard surface science techniques (e.g., goniometry, X-ray photoelectron spectroscopy). The relative biocompatibility of the substrates with cultured bovine aortic endothelial cells (BAECs) and monkey kidney epithelial cells exposed to extracts from the cpNIPAM, spNIPAM, and ppNIPAM films was assessed using pop off experiments and Live/Dead assays. In addition, the extract solutions themselves were analyzed by NMR and mass spectroscopy. We find that the diminished cell viability of BAECs exposed to cpNIPAM substrates is due to a combination of factors, including the inclusion of short chain length polymers and the presence of unreacted catalyst. This work will have valuable insights into the cytotoxicity of cpNIPAM-coated surfaces, and therefore, into the applicability of cells grown on this surface for human subjects.