The role of nanomedicine in infectious diseases of the central nervous system: a narrative review.

Infectious diseases in the central nervous system (CNS) are a global health problem, causing significant morbidity and mortality. One of the main challenges in treating CNS infections is the blood-brain barrier (BBB), which limits drug delivery to the brain. During infections, brain-resident immune cells, release inflammatory mediators, which further contribute to neuroinflammation and damage. Nanomedicine offers an alternative for CNS treatment that has been explored in several types of infections. Across preclinical studies, nanomedicine approaches have demonstrated substantial improvements in CNS delivery and therapeutic outcomes, including reductions in brain pathogen burden of up to 3 log10 colony-forming units, increases in brain drug concentrations of 3-4-fold, and survival improvements of up to 100% in selected infection models. However, the literature remains fragmented across pathogens, nanomaterial platforms, and experimental models, with few direct comparisons and limited clinical validation. This review provides a comprehensive, up-to-date synthesis of the current evidence, integrating emerging nanomedicine strategies across major CNS infections while highlighting common therapeutic approaches, clinical applications, limitations, and key gaps that must be addressed to advance these technologies toward clinical translation. It also highlights advances and techniques in nanomedicine for treating brain infections, discusses clinical applications, and promotes innovation and future directions.