טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
Ph.D Thesis
Ph.D StudentSovak Guy
SubjectBone Tissue Reaction to a Novel Titanium Nitride (TiN)
Coating on Titanium Alloy (Ti-6al-4V) Implants
and the Effect of Growth Factors and
Cell Adhesion Molecules on ...
DepartmentDepartment of Medicine
Supervisors Dr. Anna Weiss
Dr. Irena Gotman


Abstract

A new titanium nitride (TiN) coating was developed in order to improve the relatively poor wear resistance of titanium-based implants. The aim of the research was to test biocompatibility of TiN coating and its ability to undergo osseointegration, and the effects of fibronectin, insulin like growth factor-1 (IGF-1) and IGF-binding protein-5 (IGFBP-5) on osseointegration. 1x20 mm pins were implanted into the femora of six-month-old female Wistar rats. Animals were sacrificed 3 days, 10 days, 1, 2 and 6 months post-implantation. Scanning electron microscopy revealed that spongy bone anchored the implants after 10 days in the epiphysis, and after 1 month in the diaphysis. 6 months post-implantation the implant was anchored by compact bone. Bone volume and bone-implant-contact was similar for TiN-coated and uncoated implants. Mineralization tested by tetracycline incorporation was at peak 1-month post-implantation. Histochemistry of alkaline phosphatase revealed osteoblasts recruitment already 3 days post-implantation, the activity was seen mainly near implants. The activities of tartrate-resistant acid phosphatase, as a marker of osteoclasts and nonspecific esterase, as a marker of macrophages, were high until 10 days, apparently to remove blood clot and bone debris. Fibronectin, IGF-1 or IGFBP-5 adsorbed onto pins enhanced bone formation around implants, especially in the diaphysis, at 10 days post-implantation.

In summary, the findings of this research indicate that TiN-coated implants revealed good biocompatibility, underwent osseointegration at a rate similar to uncoated implants, and did not evoke inflammatory response. Hence the novel TiN-coatings  can provide a solution for titanium-based implants wear. Adsorption of fibronectin, IGF-1 and IGFBP-5 accelerates implants fixation.