Bone grafts need to comply with some criteria of biocompatibility, including favoring neovascularization, new bone formation, and discourage inflammatory response and graft rejection. It is also expected that these materials should have mechanical properties similar to those of natural bone, that is, having enough pores to permit osteoprogenitor cells and vascular endothelium penetration but maintaining strength and flexibility.
Here, a new resistant and flexible tridimensional multilayered bioceramic composite was obtained by using chitosan and hydroxyapatite in combination with cells and their associated growth factors from the bone marrow tissue, allowing the development of a biocompatible bone graft.
This multilayered graft made out of chitosan functionalized with phosphate groups and mineralized with calcium phosphate (hydroxyapatite) was analyzed with scanning electron microscopy (SEM), X ray diffraction (XRD), energy dispersive X-ray analysis (EDX) and Fourier transform infrared spectroscopy (FTIR) to assess the degree of phosphorylation and the amount of hydroxyapatite present in the graft. The composite was further characterized by mechanical testing (Vicker's microhardness test), in vitro osteoblasts culture citotoxicity tests.
The results showed that this multilayered graft has mechanical properties comparable to that of trabecular bone and it was capable to keed osteogenic cells alive.