EFFECTS OF CONCENTRATION OF NANO HYDROXYAPATITE ON BONE SCAFFOLD

Abstract

Many materials are currently in use to repair or replace bone that has been damaged due to trauma or disease, such as large bone tumors, defects, fractures, and non-unions. These include a variety of biomaterials based on ceramics, metals, polymers, and composites. These materials stand out as a potential solution, being easily available, processed and modified to suit the needs of a given application. However, many problems persist resulting from the inability to exactly match natural tissue. Metals suffer from mechanical properties far exceeding those of bone, which results in stress shielding and the subsequent weakening of the host bone tissue, thus making it susceptible to refracture. Ceramics, particularly calcium phosphate based, such as hydroxyapatite, are brittle and difficult to work into desired shapes. Finally, polymers used in medical applications, for the most part, lack the rigidity, ductility, or ultimate mechanical properties required in load bearing applications. To address the limitations of individual materials, new materials based on composites of ceramics, metals, and polymers have been proposed. In particular, ceramic/polymer composites are promising as bone substitute materials. These composites propose the use of synthetic or naturally derived materials to act as a scaffold for bone tissue ingrowth and organization, with subsequent dissolution of the scaffold material through the processes of biodegradation and bone remodeling. Use of nanotechnology in composites enhances the properties to a great extent. Ceramic/Polymer nanocomposites are the result of the combination of polymer and ceremic fillers at nanometer scale. The interaction at the nanometer scale enables them to act as molecular bridges in the polymer matrix. This is the basis for enhanced mechanical properties of the nanocomposite as compared to conventional microcomposites. Changing the concentration of ceramic nanofiller e.g. nano hydroxyapatite causes variation in physical, chemical, mechanical and biological properties of composite scaffold, such as, on increasing concentration of Hydroxyapatite, brittleness, density, compressive modulus and bioactivity increase and porosity decreases. Swelling ratio first increases and then decreases. Biodegradation first gets faster and then gets slower. Studying the effect of concentration of Nano hydroxyapatite provides a wide range of properties in scaffold and makes it easy to select a suitable concentration of nano Hydroxyapatite for bone scaffold.