Multifunctional Coatings of Titanium Implants Toward Promoting Osseointegration and Preventing Infection: Recent Developments

Abstract

Titanium and its alloys are dominant material for orthopedic/dental implants due to their stable chemical properties and good biocompatibility. However, aseptic loosening and peri-implant infection remain problems that may lead to implant removal eventually. The ideal orthopedic implant should possess both osteogenic and antibacterial properties and do proper assistance to in situ inflammatory cells for anti-microbe and tissue repair. Recent advances in surface modification have provided various strategies to procure the harmonious relationship between implant and its microenvironment. In this review, we provide an overview of the latest strategies to endow titanium implants with bio-function and anti-infection properties. We state the methods they use to preparing these efficient surfaces and offer further insight into the interaction between these devices and the local biological environment. Finally, we discuss the unmet needs and current challenges in the development of ideal materials for bone implantation.

Keywords: anti-infection; functional coatings; orthopedic titanium implants; osseointegration; titanium implants.

FIGURE 1

Types and effects of osteogenic coatings on titanium implants. The elastic coating can fill the interface gap by expansion. The implants with surface morphology coatings, inactive coatings, and bioactive coatings can promote new bone formation.

FIGURE 2

Types and effects of antibacterial coatings of titanium implants. After implantation, biofilm may be formed, leading to osteonecrosis in general. At present, to avoid infection, the coatings with inactive polymers, light-induced ROS and bioactive antibacterial agents, and the intelligent controlled release antibacterial coatings are the main antibacterial methods.