Enhancement of plasma protein adsorption and osteogenesis of hMSCs by functionalized siloxane coatings for titanium implants

Abstract

A series of sol–gel derived silicon based coatings were developed to improve the osseointegration of commer- cial titanium dental implants. The osseointegration starts with a positive interaction between the implant surface and surrounding tissues, which is facilitated by the adsorption of plasma proteins onto the biomaterial surface immediately after implantation. It is likely that the enhancement of protein adsorption to titanium implants leads to a better implant/tis- sue integration. In addition, silica based biomaterials have been shown to promote osteoblast differentiation. To improve the protein adsorption and the osteogenesis, meth- yltrimethoxysilane (MTMOS), tetraethoxysilane (TEOS), 3- glycidoxypropyltrimethoxysilane (GPTMS), and gelatin were selected to coat titanium surfaces. Compared with non- coated titanium, the functionalized coatings enhanced the adsorption of adhesive proteins such as fibronectin and colla- gen. The Si release was successfully modulated by the con- trol of the chemical composition of the coating, showing a higher dissolution rate with the gelatin and GPTMS incorpo- ration. While the roughness of commercial implants seemed to promote the adhesion of mesenchymal stem cells (MSC), the osteogenic differentiation was greater on surfaces with Si-coatings. In this study, an improved osteogenic surface has been achieved by using the siloxane-gelatin coatings and such coatings can be used in dental implants to promote osseointegration.