Chitosan nanoparticles for brain targeted nose-to-brain drug delivery in neurodegenerative disease: a comprehensive exploration of advances, limitations and future prospects

INTRODUCTION: Neurodegenerative diseases (NDDs), such as Alzheimer's and Parkinson's and epilepsy, cause irreversible nerve cell degradation, resulting in cognitive and motor decline. The blood-brain barrier (BBB) complicates treatment, limiting drug access and causing low bioavailability. Chitosan nanoparticles (CH-NPs) offer a promising solution for improving drug delivery to the brain due to their biocompatibility and ability to enhance intranasal delivery, potentially increasing therapeutic efficacy. AREAS OF COVERAGE: The review discusses advancements in chitosan-based nanoparticle drug delivery systems for NDDs, highlighting literature from 2015 to 2025. It indicates that chitosan can improve drug uptake in the brain by up to ten times and emphasizes its potential for targeted central nervous system (CNS) delivery due to its unique properties. Additionally, intranasal delivery is a non-invasive method to bypass the BBB and enhance therapeutic precision. EXPERT OPINION: CH-NPs effectively deliver therapeutics to the CNS, leveraging their mucoadhesive properties and biocompatibility to cross the BBB via intranasal delivery. This platform enhances drug uptake and retention in the brain, addressing challenges faced by traditional therapies for NDDs. Optimizing nanoparticle biomaterial properties and delivery methods could improve therapeutic precision and clinical outcomes.