| AVS 62nd International Symposium & Exhibition | |
| Biomaterial Interfaces | Wednesday Sessions |
| Session BI-WeA |
| Session: | Biophysics, Membranes and Nanoscale Biological Interfaces |
| Presenter: | Elena Liang, University of California, Irvine |
| Authors: | E. Liang, University of California, Irvine E. Mah, University of California, Irvine S. Wu, University of California, Irvine A. Yee, University of California, Irvine |
| Correspondent: | Click to Email |
The ability to control cell adhesion on material surfaces is critical to the performance and biointegration of implanted medical devices. Of particular interest to our research is developing an understanding of what role surface topography plays in cell adhesion, which could lead to simple and durable ways to engineer surfaces without having to chemically modify the surface of biomaterials. Our group found that human embryonic stem cells grown on nanopillar structures have a significantly reduced number of focal adhesions per cell and concordantly exhibit increased cell motility on the nanopillars (Kong et al. 2013). We hypothesized that pillar nanostructures would prevent cells from adhering. To test this hypothesis, we counted the number of fibroblasts adhering to a variety of surface topographies, which consisted of a flat surface, nanolines, and nanopillars, and examined cell morphology on these surfaces. We created a library of nanopillared polymethylmethacrylate (PMMA) surfaces, including a biomimetic cicada wing replicate (the surface of the wing has a high density of nanopillars with dimensions that are ideal for our studies) made by compressing a negative hPDMS stamp of the cicada wing into PMMA, and pillar arrays of approximately 200 nm diameter nanopillars with center-to-center spacing ranging from 320 nm to 692 nm fabricated with nanoimprint lithography. We also observed the focal adhesions using fibroblasts transfected with paxillin-GFP and tracked migration. After 24 hours, we found that the fibroblasts showed a spread-like morphology on the flat film while those on pillars were smaller and more equiaxed. Preliminary results show that there are noticeably fewer cells on PMMA pillars than on flat PMMA. The focal adhesions on cells on nanopillars appear smaller than focal adhesions of cells on a flat surface. Lastly, cells on nanopillars on average traveled a greater distance than cells on a flat surface. Our study shows that protruding structures in the 100-500 nm size range affect cell adhesion dynamics and structure dimensions modulate the adhesion of cells. This may provide researchers a useful means of controlling cell adhesion on surfaces of implants.