Advances in Multifunctional Bioactive Coatings for Metallic Bone Implants

Abstract

To fix the bone in orthopedics, it is almost always necessary to use implants. Metals provide the needed physical and mechanical properties for load-bearing applications. Although widely used as biomedical materials for the replacement of hard tissue, metallic implants still confront challenges, among which the foremost is their low biocompatibility. Some of them also suffer from excessive wear, low corrosion resistance, infections and shielding stress. To address these issues, various coatings have been applied to enhance their in vitro and in vivo performance. When merged with the beneficial properties of various bio-ceramic or polymer coatings remarkable bioactive, osteogenic, antibacterial, or biodegradable composite implants can be created. In this review, bioactive and high-performance coatings for metallic bone implants are systematically reviewed and their biocompatibility is discussed. Updates in coating materials and formulations for metallic implants, as well as their production routes, have been provided. The ways of improving the bioactive coating performance by incorporating bioactive moieties such as growth factors, osteogenic factors, immunomodulatory factors, antibiotics, or other drugs that are locally released in a controlled manner have also been addressed.

Recent Advances in Antibacterial Coatings to Combat Orthopedic Implant-Associated Infections

“…Similar to other medical devices and implants, most orthopedic implants generally fail due to the development of IAIs and poor tissue interconnections [ 27 , 28 ]. Such poor host integration between the implants and their surrounding bone tissues may lead to the presence of small void spaces around implants, allowing a suitable environment for bacterial adhesion and colonization [ 5 , 7 , 12 , 26 ].…”

“…The rise in life expectancy is associated with an increased demand for healthcare among the elderly with hip osteoarthritis or osteoporotic fractures, as well as an increased demand for joint replacement surgeries and development of safe and biocompatible orthopedic biomaterials for combating implant-associated infections (IAIs) [ 1 , 2 , 3 ]. Here, it is worth considering that the surgical placement of orthopedic implants inside the human body for offering biological support to injured tissues or organs and restoring biological functioning is challenging due to possible bacterial adhesion and proliferation on the surfaces, eventually leading to infections [ 4 , 5 , 6 ].…”

Metal ions: the unfading stars of bone regeneration—from bone metabolism regulation to biomaterial applications

“…Of particular interest is that free or bound metal ions can be integrated into the coating material using various methods, including chemical, thermochemical, electrochemical, and physical methods. 230 This results in stable metal ion release and improved osseointegration efficiency.…”

The activity of monocyte-derived macrophages after stimulation with platelet-rich and platelet-poor concentrates. Study on an ovine model of insertion of a tibial implant coated with silicon-doped diamond-like carbon

“…One such coating is silicon-doped diamond-like carbon (Si-DLC), which creates a barrier around a surgical-steel implant that blocks metal ions from entering the surrounding tissues, preventing allergic reactions to the components of the implant. In addition, this layer also protects the implant from the effects of ROS and RNI, as well as proteolytic enzymes released by M1-like macrophages ( 5 , 20 , 25 , 26 ).…”