Nanotechnology-Based Drug Delivery in Alzheimer’s Disease: Recent Advances, Mechanisms, and Future Directions

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder and the leading cause of dementia worldwide. Over 55 million people have dementia, 60–70% of whom have AD, with prevalence rising as populations age. AD is characterized by extracellular amyloid-β plaques and intracellular tau tangles that disrupt synaptic function and cause neuronal death. Genetic factors such as the APOE ε4 allele, environmental influences, and lifestyle choices modulate risk, and existing treatments offer only symptomatic relief without altering disease progression Nanotechnology-based drug delivery systems address bioavailability, blood-brain barrier penetration, and target specificity challenges. Engineered nanocarriers-liposomes, polymeric nanoparticles, dendrimers, and exosomesencapsulate therapeutics, protect them from degradation, and enable controlled, stimuliresponsive release in the brain. Surface functionalization with ligands like transferrin or anti-Aβ antibodies facilitates receptor-mediated BBB transcytosis, and preclinical models demonstrate improved cognition and reduced plaque burden. Clinical translation depends on manufacturing scalability, safety, and regulatory approval, but nanotechnology could transform Alzheimer’s treatment by targeting neural tissues