(160e) A Novel, Low Cost Method for Investigating the Effect of Nanotopography On Biomaterials

Although nanotopography is an integral feature of most biomaterials, not until recently have its effects come under scrutiny. Scientists have discovered that nanotopography has consequential effects and also varies tremendously in biomaterials. The pattern, its dimensions, and its surface properties can alter cell migration and morphology. This research investigates the influence of nanoscale features on cell morphology, particularly in SK-N-SH neuroblastoma cells. These cells exhibit multiple phenotypes in response to growth conditions, allowing changes in morphology to be easily recognized.

Nanofabrication can be time consuming and expensive. Here, we present a low-cost nanotopographical surface consisting of self-assembling, arrayed nanoscale islands produced through a two-step process: a thin film of gadolinium-doped ceria (GDC) is sputtered onto an yttria-stabilized zirconia (YSZ) substrate, and then annealed at high temperature. During annealing, the film breaks up into islands to relieve lattice mismatch strain between the YSZ and GDC phases. We can produce islands ranging from 10-75 nm high and 50-500 nm wide, with spacing of 20-200nm. This method can produced large areas (mm2 - cm2) uniformly covered with nanoislands at lower cost and more expediently than direct-write methods such as e-beam lithography or dip-pen lithography. Unlike polymer demixing and other self-assembly routes, the nanoislands align to the underlying substrate, providing quasi-ordered nanotopography.

To quantify the influence of these features on cells, we have examined morphology, number of adherent cells, and distribution of cytoskeletal proteins (e.g., actin) for cells cultured on nanopatterned and ?smooth? control surfaces of GDC and YSZ. Cells cultured on nanopatterned surfaces appear more rounded when compared to those cultured on a flat substrate (e.g., neural vs. fibroblast morphology), indicating that the nanoislands do alter cell function. In addition, the density of live cells was higher for nanoislands than for the flat substrate. The GDC-YSZ nanotopographical system may provide a simple, inexpensive method to explore nanotopography, ultimately enabling the creation of biomaterials that more closely resemble and mimic native tissue.