Stimulus-responsive antibacterial strategies for construction of anti-infection bone implants

Bone-related implantable hardware is expanding continuously in clinic along with growing geriatric population and orthopedic disorders and defects. Failures led by infections after implantation give rise of patient burdens physiologically and psychologically. Compared to regular debridement therapies, more and more studies have focused on stimuli-responsive smart strategies for construction of adaptively anti-infective bone implants in order to subdue current complication issues: microbial adhesion and its subsequent biofilm formation, antibiotic drug resistance and invalid bacterial elimination treatment. In this way, the implants themselves can response promptly to infection at the early infection stage. This review endeavors to summarize progresses of stimulus-responsive bone implants in the last decade from two aspects: exogenous physical factors (e.g., light, ultrasound, magnetism, and electricity) and endogenous bacterial metabolites (acid, enzymes, and ROS) as stimuli to initiate effective bactericidal effects and controlled medicine release. At the end of the article, current difficulties and future research orientations in developing anti-infective implants with high performances, long-term safety and stability are put forward. • Analyzing how bone implants achieve smart anti-infection via stimuli. • Comparing bactericidal effect and mechanism of exo-/endo-genous operations in depth. • Addressing critical challenges towards practical applications.