Research progress in anti-bacterial infection nano-delivery systems and their effects on the immune system

Abstract:

Driven by the continuous pressure of antibiotic selection, bacteria continue to evolve through multidrug resistance mechanisms, resulting in the increasing ineffectiveness of conventional antibiotic treatment and posing a severe challenge of no drug availability in clinical practice. Nano-delivery systems breathe new life into antimicrobial therapy with their designable physicochemical properties and versatile integration characteristics. Nano-delivery systems are not limited to simple drug carriers, but can be developed into a multi-functional intelligent platform integrating precise delivery, microenvironment perception, and immune reprogramming through precision design. This review systematically expounds the construction strategy of antimicrobial nano-delivery systems, sorts out the development context from drug carrier, synergistic vector, intelligent response vector to intelligent biomimetic vector. Furthermore, this review discusses the targeted design and antimicrobial component loading strategy in detail, including conventional antibiotic synergy and new antimicrobial co-delivery. The core thesis of this paper is that the application of nano-delivery systems in specific infection scenarios (e.g., intracellular bacterial infection and biofilm-associated infection) has gone far beyond simple delivery, and instead actively regulates host immune homeostasis, synergistically enhancing antibacterial effects by regulating innate immunity (e.g., macrophage polarization and neutrophil function) and activating adaptive immunity. Finally, this paper makes an outlook on the challenges and future development directions of this field, emphasizing that through cross-scale design and multi-mechanism synergy, nano-delivery systems are expected to provide a new generation of therapeutic strategies that are efficient, safe, and less likely to induce drug resistance for drug-resistant bacterial infections.