Title:Cell Adhesion Response on Femtosecond Laser Initiated Liquid Assisted Silicon Surface
Volume: 14
Issue: 5
Author(s): M. Ulmeanu, L. E. Sima, D. Ursescu, M. Enculescu, X. Bazan and I. Quintana
Affiliation:
Keywords:
Femtosecond laser, liquid assisted, actin filaments organization.
Abstract: Silicon substrates were irradiated at normal incidence with a femtosecond Ti:sapphire laser (Quatronix, 90 fs
pulse duration, 1 kHz repetition rate, M2 ~ 1.2, maximum energy peak 350 mJ ) operating at a wavelength of 400 nm and
focused via a microscope objective (Newport; UV Objective Model, 37x 0.11 N.A.). The laser scanning was assisted by
liquids precursors media such as methanol and 1,1,2-trichlorotrifluoroethane. By altering the processing parameters, such
as incident laser energy, scanning speed, and different irradiation media, various surface structures were produced on areas
with 1 mm2 dimensions. We analyzed the dependence of the surface morphology on laser pulse energy, scanning
speed and irradiation media. Well ordered areas are developed without imposing any boundary conditions for the capillary
waves that coarsens the ripple pattern. To assess biomaterial-driven cell adhesion response we investigated actin filaments
organization and cell morphological changes following growth onto processed silicon substrates. Our study of bone cell
progenitor interaction with laser nanoprocessed silicon lines has shown that cells anchor mainly to contact points along
the nanostructured surface. Consequently, actin filaments are stretched towards the 15 µm wide parallel lines increasing
lateral cell spreading and changing the bipolar shape of mesenchymal stem cells.
