Advances in nanotechnology versus stem cell therapy for the theranostics of Huntington's disease

Huntington's disease (HD) is a neurological disorder characterized by a reduction in medium-spiny neurons in the brain. Currently, there is no cure for HD and treatment relies on symptomatic therapy. The generation of stem cells, including neural, mesenchymal, and pluripotent, through conventional strategies or direct cell reprogramming, has revolutionized HD therapy research. Due to their unique ability to differentiate into a variety of cells, self-renew and grow, stem cells have become an area of interest for treating various complex and unresolved neurodegenerative disorders. Nanotechnology has emerged as a novel approach with great potential for treating HD with reduced side effects. Nanoparticles (NPs) can act as nanovehicles for delivering therapeutic agents, including siRNAs, stem cells, neurotrophic factors, and different drugs. Additionally, NPs can be used as an alternative treatment based on their antioxidant and reactive oxygen species -scavenging properties that protect neuronal cells. Some NPs even exhibit the ability to interfere with the protein aggregation of mutant Huntingtin proteins during neurodegenerative processes. This review focuses on the most studied NPs for treating HD, including polymeric, lipid-based, liposomes, solid lipid and metal/metal oxide NPs. The combination of NPs with stem cell therapy has great potential for neurodegenerative disease diagnosis and treatment. NPs have been used to manage the cellular microenvironment, improve the efficiency of cell and drug delivery to the brain, and enhance stem cell transplant survival. Understanding the characteristics of the different NPs is essential for applying them for therapeutic purposes. In this study, the biology of HD as well as the benefits and drawbacks of using NPs and stem cell therapy for its treatment are discussed.