Glass-based coatings on biomedical implants: a state-of-the-art review

Abstract Bioactive glasses, invented by Prof. Larry L. Hench in the late 1960s, have revolutionized the field of biomaterials as they were shown to tightly bond to both hard and soft living tissues and to stimulate cells towards a path of regeneration and self-repair. However, due to their relatively poor mechanical properties (brittleness, low bending strength and fracture toughness), they are generally unsuitable for load-bearing applications. On the other hand, bioactive glasses have been successfully applied as coatings on the surface of stronger/tougher substrates to combine adequate mechanical properties with high bioactivity and, in some cases, additional extrafunctionalities (e.g. antibacterial properties, drug release). After giving a short overview of the main issues concerning the fabrication of glass coatings, this review provides a state-of-the-art picture in the field and specifically discusses the development of bioactive and hierarchical coatings on 3D porous scaffolds, joint prostheses, metallic substrates (e.g. wires or nails) for orthopedic fixation, polymeric meshes and sutures for wound healing, ocular implants and percutaneous devices.