Physico-chemical and biological evaluation of excimer laser irradiated polyethylene terephthalate (pet) surfaces.
Résumé
The aim of this work was to investigate the consequences of excimer laser irradn. on the physico-chem. and biol. properties of polyethylene terephthalate (PET) films, currently used for medical devices. Three PET films from different origins were studied in the present work, chosen with respect to their chem. and phys. properties, which are of high importance for ulterior medical application as vascular prostheses. Multiple assays were carried out to characterize the phys. and chem. effects of the laser irradn.: surface morphol. tests (light microscopy, Dektak profilometer and confocal laser scanning microscopy) showed the strong transformation of the surface with the laser treatment. Contact angle measurements revealed a significant increase of the surface energy for each PET depending on the applied fluency. Finally XPS characterization of the surface demonstrated the appearance of new chem. species favorable for cell attachment. This aspect had to be strongly considered regarding to the multiple biol. effects of laser irradiated surfaces on living cells. Different cell culture expts. were carried out with L132 human epithelial cells after 6-days culture: proliferation and vitality rate, cell adhesion and cell morphol. Results clearly revealed that laser treatment improved cell proliferation (up to 140% with respect to controls), vitality (10% higher than controls), morphol. and adhesion kinetics (more than 16% of control). A significant correlation (R2=0.906) was also established on one PET between the fluencies of laser treatment and the cellular response. These results emphasized high importance of the choice of the PET material for a medical application: only one of the three considered PET films showed really improved cellular response.