IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Biomaterials Thursday Sessions
       Session BI-ThA

Paper BI-ThA7
Surface Characterization and HCAEC Adhesion Studies of IPN Modified 316 L Stainless Steel

Thursday, November 1, 2001, 4:00 pm, Room 102

Session: Cell-Surface Interaction
Presenter: G.M. Harbers, Northwestern University
Authors: G.M. Harbers, Northwestern University
T.A. Barber, University of California, Berkeley
M.E. Yanez, University of California, Berkeley
H.B. Larman, University of California, Berkeley
K.E. Healy, University of California, Berkeley
Correspondent: Click to Email
Interactions between synthetic biomaterials and components of the cardiovascular system still remain poorly understood. In particular, the process of restenosis following intravascular stent deployment remains a significant problem. Coatings that minimize protein adsorption and monocyte adhesion and proliferation may reduce late-term in-stent restenosis and prevent secondary interventions. In this work, a previously developed non-fouling P(AAm-co-EG/AA) interpenetrating polymer network (IPN) was applied to clinically relevant cardiovascular stent material (316L SS). The transfer of the technology from previous substrates (quartz, TiO@sub 2@/Ti, polystyrene) to SS was confirmed using water contact angle goniometry, XPS, and cell-material interactions. Water contact angle data was similar to what was previously reported for quartz substrates and XPS confirmed the addition of each subsequent layer. To test the ability of the modified material to resist cell adhesion, substrates were seeded with primary human coronary artery endothelial cells (HCAECs). Following a 24h incubation, cells were labeled and examined using fluorescent microscopy. HCAECs adhered to both the unmodified SS and the positive control (TCPS) but not to the IPN modified material (TCPS>SS>>IPN~PEG(NH@sub 2@)@sub 2@; 8875±2128, 6972±721, 124±22, and 99±29 cells/cm@super 2@ on respective surfaces). Cells on unmodified SS coupons had a similar morphology to those seeded onto TCPS. However, the few viable cells that attached to the IPN and PEG(NH@sub 2@)@sub 2@ remained spherical and non-spread. It has been proposed that endothelialization of the stent surface can improve stent performance by creating a native tissue layer. Therefore, since the IPN/316L SS system is amenable to peptide modification, the identification of endothelial cell specific peptides to promote preferential endothelial cell adhesion, migration, and proliferation is under investigation.