Hydroxyapatite-packed chitosan-PMMA nanocomposite: A promising material for construction of synthetic bone

Abstract

Natural bone is a composite material composed of organic compounds (mainly collagen) and inorganic compounds (minerals). The inorganic or mineral component of bone primarily consists of crystalline hydroxyapatite (HAp), [Ca 10(PO4)6(OH)2], which is present in bones as a major component (60-65%). In recent years, bioactive polymer/HAp nanocomposite materials have been investigated extensively as templates for the regeneration and reconstruction of bone tissue. The advantages of using polymeric biomaterials include ease of manufacturing the components with various simple as well as complex shapes, reasonable cost, and their ability to possess a wide range of physical and mechanical properties. Among other biomaterials, chitosan, a natural polysaccharide composed of glucosamine and N-acetylglucosamine units linked in ?-(1-4) manner and derived from chitin by partial or complete deacetylation, has played a major role in bone tissue engineering over the last two decades. However, the poor mechanical strength of chitosan has restricted its practical application in bone tissue engineering. Thus, enhancement of the mechanical properties of chitosan is highly desirable. Blending of chitosan with a synthetic polymer having good mechanical properties (e.g. poly methylmethacrylate) could be helpful in increasing the mechanical properties of chitosan. Moreover, the biodegradability and biocompatibility of chitosan makes HAp-packed chitosan nanocomposite materials attractive for the building of synthetic bone. This chapter describes natural bone structure, polymer blends, and recent advances in polymer/(nano)HAp nanocomposites for application as synthetic bone © 2013 Springer-Verlag Berlin Heidelberg.