Investigation of effects of Argenine–Glycine–Aspartate (RGD) and nano-scale titanium coatings on cell spreading and adhesion

This paper examines the effects of physical and chemical surface modifications on the biocompatibility of silicon surfaces that are relevant to implantable silicon Bio-micro-electro-mechanical systems (BioMEMS). Two types of surface modifications were explored. The first involved the deposition of nano-scale biocompatible layers of pure titanium on silicon, while the second explored the covalent attachment of the binding peptide Argenine–Glycine–Aspartic acid (RGD) for improved cell adhesion. Improvements in biocompatibility were assessed through examination of cell areas after culture, as well as the measurements of adhesion strengths, as determined by shear assay techniques. The titanium nanolayers and the RGD coating resulted in improvements in biocompatibility. Increased cell spreading areas and improved adhesion strength were obtained from short and long-term studies of Human Osteosarcoma (HOS) cells cultured on the coated surfaces. RGD functionalization resulted in the greatest improvement in cell spreading area and adhesion strength for short culture times. The effects of the titanium, while less than those of RGD for short culture times, appeared to be greater after 48 h of culture.