Surface immobilization and bioactivity of TGF-β1 inhibitor peptides for bone implant applications

TGF-β1 is the most related cytokine with the production of fibrotic tissue. It plays an important role on the production of collagen by fibroblasts and other types of cells. The inhibition of this cytokine reduces fibrosis in various types of tissue. Biofunctionalization of dental and orthopedic implants with biomolecules enables modification of the physical, chemical and biochemical properties of their surfaces to improve its biological and clinical performance. Our objective was to develop a reliable method to immobilize oligopeptides on Ti surfaces to obtain a surface with TGF-β1 inhibitory activity that will potentially minimize fibrotic encapsulation of implants during the process of osseointegration. We covalently immobilized TGF-β1 inhibitor P17-peptides on Ti surfaces and assessed by characterizing each step of the process that we successfully biofunctionalized the implant surfaces. High amounts of peptides were anchored and homogeneously distributed on the surfaces with mechanical and thermochemical stability after in vitro simulated challenges. Notably, the immobilized peptides retained their TGF-β1 inhibitory activity in vitro. Thus, these biofunctional coatings are potential candidates for inducing a fast and reliable osseointegration in vivo.