Investigation of the effects of alkane phosphonic acid/RGD coatings on cell spreading and the interfacial strength between human osteosarcoma cells and Ti-6Al-4V

This paper presents the results of an experimental study of the effects of alkyl phosphonic acid/RGD complexes on cell spreading and the interfacial strength between human osteosarcoma (HOS) cells and Ti-6Al-4V surfaces. The initial stage of cell spreading is shown to be accelerated by the coatings in 9-day cell culture experiments. The adhesion between human osteosarcoma (HOS) cells and alkyl phosphonic acid/RGD-coated surfaces is also quantified by performing shear assay experiments on coated and uncoated Ti-6Al-4V specimens. These show that the interfacial shear strengths required to detach the HOS cells from the coated/uncoated specimens, increase from approx. 407 Pa (in the case of the uncoated samples) to 80 Pa in the case of the of alkyl phosphonic acid/RGD coated samples. The increase is attributed to the tethering effect of the of alkyl phosphonic acid/RGD complexes on the HOS cells. The implications of the results are then discussed for improving the wound healing and the osseointegration of biomedical implants fabricated from Ti-6Al-4V.