Processing of biomaterials for bone tissue engineering: State of the art

Bones are the functional tissue, to provide structural support, protect vital organs, store minerals, helps in multi-directional motion and bear load of our body. Fracture of bones, in which continuity of bone tissue breaks, which occurred due to trauma (high intensity impact) and over stressing are treated with help of bone implants. Bone implants are fabricated through biomaterials which are categorized as as: (a) first generation, (b) second generation and (c) third generation biomaterials. First generation implants are bioinert, second generation implants are biodegradable, bioinert and bioactive. Third generation implants focuses on stimulating specific cellular response at molecular level along with the properties of second generation. Bone tissue engineering (BTE) is responsive for the evolution of third generation implants, where the main focus is to create the environment which helps to stimulate the cell response in direction of bone regeneration. This aim is achieved with engineered tissue implant which includes: (a) scaffold for architectural support & cell homing, (b) osteogenic cells and (c) signaling growth factors. Tissues in human body are the 3D repeating unit cells also called as extra cellular matrix (ECM). Similarly scaffold is the artificial 3D porous structure of biomaterials (ceramics, metals and polymers) which mimic those 3D repeating unit cells or ECM. Scaffold is a backbone or fundamental unit of BTE. Success of scaffold decides the success of engineered bone tissue implant. This review summarizes the factor influencing BTE, factor involved in selection of material for scaffold fabrication and trending fabrication methods for BTE scaffolds.