Cellular reactions toward nanostructured silicon surfaces created by laser ablation

Abstract

Silicon wafers were structured with a femtosecond laser on the cm2 scale with high spatial frequency laser-induced periodic surface structures. These areas are characterized by regular parallel ripples with a period of the order of 100 nm. The particular ripple spacing is determined by the illumination wavelength of the tunable femtosecond laser. The cellular reaction to the structured silicon wafers and to the same materials, coated with calcium phosphate nanoparticles by electrophoretic deposition, was studied using L929 fibroblasts, human mesenchymal stem cells, and epithelial cells. The cells adhered uniformly to structured and unprocessed areas after seeding but significantly preferred the unstructured silicon after 48 h. This behavior disappeared after coating the structured surface with calcium phosphate nanoparticles.