Metallic Nanomaterials for Bone Tissue Engineering.

Conventional grafting techniques for bone regeneration are currently being replaced by tissue engineering approaches of using 3D biomimetic materials. Of these biomaterials, metals have the highest mechanical strength; moreover, they play a major role in accelerating bone formation and promoting bone regeneration. They act as cofactors for enzymes, serving as a structural component of bone forming enzymes and proteins, stimulating angiogenesis, increasing extra-cellular matrix synthesis, promoting bone formation, and inhibiting bone resorption. Metals have the inherent ability to promote osseointegration and osteoconductivity and possess antimicrobial activity. The current developments in bone tissue engineering focus on metal surface modifications by physical and chemical treatments to improve their bioactivity. Based on the recent literature available, this review aims at discussing the biological role of metals, namely Zn, Ti, Zr, B, Sr, Mg, Ag, and Cu along with their surface modifications for significantly enhanced bone regeneration.