Chitosan-nanohydroxyapatite composites: Mechanical, thermal and bio-compatibility studies

Bionanocomposites of chitosan were prepared with nanohydroxyapatite (nHA) using 2-hydroxyethyl methacrylate (HEMA) as coupling agent. The tensile and flexural properties for 8% nHA loading showed optimal values. Compressive modulus also considerably increased from 525.16 MPa (0% nHA) to 1326.5 MPa with 10% nHA. Surface functionalization of fillers along with the addition of HEMA as coupling agent led to enhanced mechanical properties similar to human bone. The mechanical properties were further analyzed using micromechanical theories which indicated good interfacial adhesion between the matrix and fillers. The composites showed cytocompatibility. Multiple layers of apatite formation have been observed when the nanocomposites were soaked in simulated body fluid (SBF). Hence, these composites showed potential for bone substitute applications.