Neuronal attachment and outgrowth on a micropatterned fluorinated polyimide surface.

In this study, we investigated the adhesion and neurite outgrowth of nerve cells on a fluorinated polyimide film micropatterned by ion irradiation. We used fluorinated polyimide because of its biocompatibility and excellent thermal and mechanical properties for ion irradiation. Rattus norvegicus chromaffin (PC12) cells were used for in vitro studies. The polyimide films were irradiated with He(+), Ne(+), or Kr(+) ions in a fluence range from 10(13) to 10(15) ions/cm(2) at 50 keV. PC12 cells selectively adhered to the polyimide film micropatterned by ion irradiation. The total neurite length for PC12 cells grown on the Kr(+)-irradiated film was the longest; the neurite length on the film irradiated by Kr(+) after 9 days was approximately five times longer than that for cells grown on the He(+)-irradiated film, i.e., 135 micro m. In addition, the PC12 differentiation rate on the ion-irradiated polyimide films also showed a similar trend to the total neurite length for PC12 cells cultured on the films: the rate decreased in the order Kr(+) > Ne(+) > He(+). This initial study indicated enhanced neurite outgrowth and differentiation of PC12 cells on fluorinated polyimide film micropatterned by ion irradiation.