Cellular responses to nanotopology of polymeric surfaces fabricated with AAO nanoimprinting

We made various patterns on the PMMA surfaces and observed the cellular responses on them. Nanoimprinting using AAO (anodized aluminum oxide) template was used for the topology control of polymeric culture surfaces. AAO has numerous regularly-spaced nanopores. The pore diameter and the center-to-center pore distance can be easily controlled by altering the anodizing and etching conditions. One of the main advantages of using AAO as a template in nanoimprinting is that nanometerscale structure templates larger than 25 cm² are easily, economically and quickly fabricated, which are suitable for various cellular studies. We cultured fibroblast on the variously nanopatterned surfaces directly or after surface treatment with collagen, O₂ plasma, or both. The cellular activities of fibroblasts on 420nm-nodule pattern treated with both were significantly retarded at 24 hours. Fibroblasts also showed significantly different activities among different patterns. In the time-lapse observation of initial adhesion in stressed condition (ambient temperature and no CO₂ supply) from 3.5 hours to 5.5 hours after seeding, we could conclude that fibroblast do not like 420nm-nodule pattern for their initial adhesion as fibroblasts on 420nm-nodule pattern markedly changed their shape to round form while those on 90nm-nodule pattern maintained their shape.