Polymyxin B delivery systems: smart solutions for improved antibacterial activity and reduced toxicity

Polymyxin B (PMB) serves as the last-line drug for treating multidrug-resistant Gram-negative bacterial infections. However, its clinical application is limited due to significant nephrotoxicity and neurotoxicity. In recent years, smart drug delivery systems have emerged as a research hotspot, aiming to optimise the functions and therapeutic effects of PMB. This article systematically reviews the structural characteristics and antibacterial mechanisms of PMB, as well as the challenges it faces in treating drug-resistant bacterial infections. The progress in smart delivery strategies for PMB is also discussed, including multidrug-resistant delivery, anti-biofilm technologies, targeted delivery, local administration, and synergistic treatment strategies. These strategies offer new directions for the precise treatment of PMB by increasing local drug concentration, reducing toxicity, enhancing the antibacterial spectrum, and inhibiting drug resistance.