Characteristics and cyto-compatibility of Collagen/Ca–P coatings on Ti6Al4V substrate

The surface modification method for a substrate affects its cyto-compatibility. Collagen coating has been considered as an effective way to vary the biological interactions occurring on the Ti6Al4V substrate. However, a uniform collagen coating is difficult to be prepared by direct collagen coating method. In this study, a simple and efficient method was developed to coat a homogenous collagen top layer on a Ti6Al4V sample that was precoated with a biomimetic Ca–P intermediate layer. Scanning electron microscopy (SEM) observations show that a non-uniform collagen coating formed on the surface of a pristine Ti6Al4V substrate, whereas a continuous and homogenous collagen coating formed on a Ti6Al4V surface pre-coated with Ca–P. Human osteosarcoma cells (HOS) were cultured and their cell morphology examined using SEM after 3 and 24 h. After seeding the cultured cell onto the substrates, cell proliferation was measured using the AlamarBlue assay at 1, 5, and 10 days. It was found that cells seeded onto collagen and Collagen/Ca–P coated substrates yielded well-developed filopodia and lamellipodia. However, the cell proliferation of Collagen/Ca–P was significantly higher than those of the other specimen for 5- and 10-day culture specimen. These results suggest that the proposed method can be used to deposit a uniform collagen coating on specimens for biomedical applications.