Nanotechnology for efficient delivery of TCM active ingredients in treating brain diseases.

Brain diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), brain tumors, and stroke, remain difficult to treat due to the restrictive nature of the blood-brain barrier (BBB). Traditional Chinese medicine (TCM) bioactive compounds offer multitarget therapeutic potential, but their clinical translation is limited by poor solubility, instability, rapid clearance, and insufficient brain exposure. Nanodelivery systems can enhance pharmacokinetics and enable brain-targeted delivery via engineered nanocarriers that exploit multiple BBB-crossing routes. This review summarizes nanotechnology-based strategies that facilitate efficient BBB transport, targeted brain accumulation, and microenvironment-responsive release of TCM-derived bioactives. Emphasis is placed on rational nanocarrier design, including biomimetic surface modification, physicochemical optimization, multicomponent integration, and stimulus-responsive systems that improve spatiotemporal control and therapeutic precision. Collectively, these strategy-oriented principles provide a translational framework for advancing nano-enabled TCM therapeutics in complex brain disorders.