Preparation of magnetic iron oxide/hydroxyapatite/chitosan rods by in situ precipitation

Chitosan (CS) is suggested for using in orthopedic applications to provide temporary mechanical support for the regeneration of bone cell ingrowth due to its good biocompatible, non-toxic, biodegradable, and inherent wound healing characteristics. In the present study magnetic iron oxide/hydroxyapatite (HA)/chitosan rods were prepared by blending magnetic iron oxide/hydroxyapatite with chitosan via in situ precipitation. Magnetic iron oxide/ hydroxyapatite was obtained by co-precipitation method. X-ray diffraction (XRD), size distribution and magnetic measurements were performed to characterize the as- prepared magnetic iron oxide/hydroxyapatite, the results confirmed the formation of magnetic iron oxide/hydroxyapatite with particle size of around 1380 nm, and its saturated magnetic intensity (M_s) was about 33.3 emu. When the total inorganic and CS content kept constant, effect of the ratio of magnetic iron oxide and hydroxyapatite on the mechanical properties was invested, the reults showed that the best ratio of magnetic iron oxide and hydroxyapatite was 3:17, and the effect of the ratio of magnetic iron oxide/HA and chitosan on the mechanical properties was also investigated, 9:91 was the best ratio. It could be also concluded from the three point bending test that the mechanical properties improved as the inorganic content decreased. Bending strength and bending modulus of the magnetic iron oxide/HA/CS composite were 87.0 MPa and 1.57 GPa, respectively. The mechanical properties of magnetic iron oxide/HA/CS composites were stronge while compared to those of human bones, due to the special performances of magnetic iron oxide and hydroxyapatite, this composite could have potential use in bone repair domain. The microstructure studies of magnetic iron oxide/hydroxyapatite/ chitosan rods were carried out by scanning electron microscopy (SEM), and SEM micrographs supported the results of the three point bending test.