Nanotechnology-based delivery of therapeutics through the intranasal pathway and the blood–brain barrier for Alzheimer's disease treatment

Background: drugs for Alzheimer's disease (AD) fail to exhibit efficacy in clinical trials for a number of reasons, a major one being blood-brain barrier (BBB) permeability. Meanwhile, the increasing incidence of this disease emphasizes the need for effective therapeutics. Herein, we discuss novel nanoplatform technologies developed for the effective delivery of AD drugs by traversing the BBB. Main text: the interfacial and surface chemistry of nanomaterials is utilized in several industries, including pharmaceutical, and has drawn considerable attention in the field of nanotechnology. Various reports have suggested the potential of nanotechnology for AD treatment, describing unique drug carriers that improve drug stability and solubility while maintaining therapeutic dosages. These nanotechnologies are harnessed for the transport of drugs across the BBB, with or without surface modifications. We also discuss the transfer of drugs via the nose-to-brain pathway, as intranasal delivery enables direct drug distribution in the brain. In addition, nanomaterial modifications that prolong drug delivery and improve safety following intranasal administration are addressed. Conclusion: although several studies have yielded promising results, limited efforts have been undertaken to translate research findings into clinical contexts. Nevertheless, nanomaterials hold considerable potential for the development of novel effective therapeutic solutions against AD.