Hydroxyapatite-Chitosan and Gelatin Based Scaffold for Bone Tissue Engineering

Bone tissue engineering, using a porous scaffold material to induce the formation of bone from the surrounding tissues has some distinct advantages over autografting and allografting, and it is a rapidly growing alternative approach to heal damaged bone tissue. The current study focuses on fabrication and characterization of hydroxyapatite and natural biopolymer composite for improved bone repair and regeneration. The porous composite scaffold containing hydroxyapatite (HAp), chitosan and gelatin having 3D network of interconnected pores with an average pore size of 150 mu m was fabricated using freeze drying method. Glutaraldehyde was used as a cross linker between chitosan and gelatin. Characteristic IR band for (-C=N-) group observed in IR study of the prepared scaffold indicated the crosslinking ability of glutaraldehyde with chitosan and gelatin. Total porosity in the scaffold varied between 60 and 70% as determined by Archimedes principle and depended on the solids loading of the scaffold. Microstructural analysis using field emission scanning electron microscopy (FESEM) showed an interconnected porous network in the scaffold where HAp nanoparticles were found to be dispersed in the biopolymer matrix. Thick bone like apatite layer deposition was observed on the surface of the scaffold on immersing it into simulated body fluid (SBF) at 37 degrees C for 7 days. The developed scaffold exhibited a compressive strength of 1.75 MPa which is close to the lower limit of compressive strength of spongy bone. These types of composite scaffolds find application as efficient biomaterial for natural bone tissue regeneration and bone tissue engineering.