BONE REGENERATION AND REPAIR
Bone healing involves a sequence of biochemical events that should not be disturbed by the
Presence of a composite or scaffold. The chemical and technological versatility of chitosan enables
researchers to prepare elaborated composites: for example, the research works on bone regeneration with the
aid of bone cements have recently become more refined in terms of the effects of chitosan composites on the
cells involved in the healing process. The use of nano-hydroxyapatite as well as other inorganics in
conjunction with variously modified chitosan is greatly contributing to the advancement and exploitation of
chitosan composites for bone healing. With the advent of nanotechnology the applications of fairly non-toxic
nanocrystalline hydroxyapatite extends from bone repair and augmentation to the delivery of drugs, growth
factors and genetic material to the bone: for this purpose, particles of uniform size with controlled
morphology can be manufactured by using macromolecules as templates. A number of advantages have
become evident, particularly when Nano-hydroxyapatite is crystallized using biomimetic methods, or when
the biopolymers are submitted to bio mineralization. The hydroxyapatite nanoparticles influence favourably
the morphology of attached cells, as a consequence of the adsorption of extracellular matrix proteins from
serum that in turn bind osteoblast precursors. Thus, an additional peculiarity of chitosan emerging from the
most recent studies is the capacity to influence both the mineralization and the cell activity. Chitosan, Ncarboxymethyl
chitosan, fibroin and poly (L-lactic acid) are at the basis of new strategies useful to stimulate
stem cells to become osteoblasts, and to make co-cultures of osteoblasts and osteoclasts. (Muzzarelli R.A.A,
et.al. 2010).