Biofunctionalization of titanium surfaces with heparin-binding biomolecules to enhance osteointegration of implants
Document typeMaster thesis
Rights accessOpen Access
For orthopaedic, dental or craniofacial applications osteointegration is critical for short-term initial stability and long-term success of the implant. Important efforts have been made in the past to optimize the osteointegration of titanium implants in bone-contact applications, focusing mainly on biofunctionalization methods of its surface to reduce healing times and accelerate integration into the host tissue. In the present in vitro study a heparin binding peptide (FHRRIKA) and a recombinant fragment of fibronectin, which contains an heparin binding domain as well (HBII), have been covalently immobilized onto titanium. Both the peptide and the recombinant protein fragment promoted the adhesion and proliferation of osteoblast-like cells (Saos-2) and fibroblasts (HFFs). In contrast, they only supported modest levels of cell spreading. Titanium functionalized with the peptide stimulates the expression of both osteoblast- and fibroblast-related genes, while titanium functionalized with the protein fragment stimulates only osteoblastic differentiation genes, being this strategy more selective. This study demonstrates that heparin-binding domains play an important role in a variety of biological processes, however it must be noted that surfaces coated with FHRRIKA or HBII did not reach the efficiency required for a material to be implanted. Nevertheless, the possibility of include in a single coating several cell surface receptors found in osteoblasts might be an interesting approach for developing novel biomaterial surfaces used in bone contact applications, in this coatings FHRRIKA or HBII could be included.