Nano-antioxidants for neurodegenerative disorders: a scoping review

Antioxidants showed usefulness in treating or preventing neurodegenerative diseases (NDDs). However, antioxidants have limited bioavailability owing to the BBB limiting drug access to the CNS. Nano drug delivery systems (NDDS) provide innovative solutions to pass the BBB and enhance antioxidant activity. Although an incredible number of preclinical trials are in the literature, it has not been translated into clinical practice.

This scoping review aims to systematically summarize the current evidence, study the characteristics of the available literature, and identify research gaps.

This review was conducted following the PRISMA-ScR guidelines. We searched PubMed for all primary studies investigating nano-antioxidants in the context of NDDs within the last five years. Data were extracted and analyzed on the year of publication, contributing affiliations, type of research, the investigational antioxidant agent, and the drug delivery matrix. In addition, we examined the association between NDDS and the year of publication, plus the association with the country of publication.

A total of 171 were included in the analysis. We found that all the articles included were pre-clinical trials. Organic and lipid-nanocarriers were the most frequently adopted (31.95% and 26.04%, respectively). Surprisingly, nanoplatforms were mentioned in only one trial. Our analysis showed that only 24 articles (14.04%) of the included trials adopted comparative studies.

We noticed a significant underrepresentation of nanoplatform applications and comparative designs. We provided new insights into nanoplatforms research. Moreover, we believe that it is crucial to establish rigorous validation systems and methodological approaches to predict the destiny of these nanocarriers in vivo and inspire the formulation of cost-effective functionalized nanoparticles with less stability or sterility drawbacks.