Development of biomimetic composite coatings on metallic surfaces for bone tissue engineering

Abstract

Bone Tissue Engineering (BTE) is a fascination field of research owing to the increased number of diseases related to orthopaedics each year. Artificial bone grafts are biomaterial intended to heal the defective site within the stipulated duration of time. The complexity involved in designing an ideal replacement for the natural bone is a challenging task. Research today is focused towards designing a biomaterial that will aid in the rapid regeneration of the natural bone along with the suitability of the matrial in in vivo condition. Biomaterials for BTE vary widely depending on the defect/disease and the site of implantation. Metallic biomaterials are of two types depending on their degradability in biological condition. Both inert and biodegradable metals are widely used in orthopaedic surgery to compensate the lost bone mass. The only goal of a biomaterial is to mimic the natural bone in its functions and characteristics. Among the various artificial implant biomaterial used; the role cannot be fulfilled by one substance alone. Composite material is of great advantage in the field of BTE. The thesis focuses on targeting three different bone failures where the circumvent of the biomaterial is very crucial. The first focus in the study is to improve the osteointegration potential of the implant surface in addition to enhancing the wear and corrosion resistance. The main disadvantage using titanium metal as a biomaterial is its non-osteointegration and poor wear resistance. In order to overcome these two drawback surface modification of the titanium metal using mixed metal oxide composites of TiO2-ZrO2, TiO2-Nb2O5, TiO2-Ta2O5 and TiO2-SiO2 through Sol-Gel Synthesis is adopted. This mixed oxide acts a first layer and the second layer comprising of strontium incorporated hydroxyapatite. The reason behing the selection of the strontium and hydroxyapatite is due to its proven excellent biological behaviour. Basic surface morphological studies such as X-Ray Diffraction (XRD), infrared (IR) and Scanning Electron Microscope - Energy Dispersive X-ray (SEM-EDAX) were carried out to know the crystalline phases of the ceramic oxides formed on the surface. newline newline newline