A Review of Biofilms on Medical Devices: Formation, Resistance Mechanisms, and Control Strategies

The formation of biofilms on medical devices is a major public health challenge, associated with persistent infections, increased antimicrobial resistance and device failure. Biofilms are structured microbial communities, integrated into an extracellular matrix that they produce, giving them protection against antibiotics and host immune defenses. This review provides a synthesis of the mechanisms of biofilm formation, the molecular basis of their resistance, and current and emerging strategies for their prevention and control. This narrative review summarizes (i) the bacterial composition of device-associated biofilms, (ii) the sequential mechanisms of biofilm formation (initial adhesion, maturation, dispersion), (iii) the molecular and physiological basis of biofilm-mediated antimicrobial resistance, and (iv) prevention and control strategies, with particular emphasis on antibacterial and anti-adhesive coatings for orthopedic and dental implants. Surface engineering (anti-adhesive, antimicrobial, nanostructured and biomimetic coatings), anti-biofilm agents (enzymes, quorum sensing inhibitors, bacteriophages), physical approaches (ultrasound, photodynamic therapy) and combined multimodal strategies emerge as the most promising directions. No single strategy ensures complete prevention or eradication of biofilm-associated infections; multidisciplinary multimodal approaches integrating smart biomaterials, controlled antimicrobial release, and artificial intelligence-assisted surface design represent the most realistic clinical pathway forward.