Potential of Nano-Antioxidants and Nanomedicine for Recovery from Neurological Disorders Linked to Long COVID Syndrome

Abstract

Long-term neurological complications, persisting in patients who cannot fully recover several months after severe SARS-CoV-2 coronavirus infection, are referred to as neurological sequelae of the long COVID syndrome. Among the numerous clinical post-acute COVID-19 symptoms, neurological and psychiatric manifestations comprise prolonged fatigue, “brain fog”, memory deficits, headache, ageusia, anosmia, myalgias, cognitive impairments, anxiety, and depression lasting several months. Considering that neurons are highly vulnerable to inflammatory and oxidative stress damages following the overproduction of reactive oxygen species (ROS), neuroinflammation and oxidative stress have been suggested to dominate the pathophysiological mechanisms of the long COVID syndrome. It is emphasized that mitochondrial dysfunction and oxidative stress damages are crucial for the pathogenesis of neurodegenerative disorders. Importantly, antioxidant therapies have the potential to slow down and prevent disease progression. However, many antioxidant compounds display low bioavailability, instability, and transport to targeted tissues, limiting their clinical applications. Various nanocarrier types, e.g., liposomes, cubosomes, solid lipid nanoparticles, micelles, dendrimers, carbon-based nanostructures, nanoceria, and other inorganic nanoparticles, can be employed to enhance antioxidant bioavailability. Here, we highlight the potential of phytochemical antioxidants and other neuroprotective agents (curcumin, quercetin, vitamins C, E and D, melatonin, rosmarinic acid, N-acetylcysteine, and Ginkgo Biloba derivatives) in therapeutic strategies for neuroregeneration. A particular focus is given to the beneficial role of nanoparticle-mediated drug-delivery systems in addressing the challenges of antioxidants for managing and preventing neurological disorders as factors of long COVID sequelae.

Gout Management Using Nanocarrier Systems: A Review

“…These nanocarriers have the capacity to both protect and enhance the bioavailability of unstable encapsulated biomolecules . These findings hold great promise as vehicles for transporting poorly therapeutic agents to target sites, as reported by a collective of previous research. − Various types of nanocarriers including lipidic and polymeric nanocarriers are engineered to encapsulate active agents for the treatment of gout and are shown by their structures in Figure .…”

Relationship of quercetin intake and oxidative stress in persistent COVID

“…The use of conjugates and nanocarriers based on different materials is an option to consider for Quercetin; these nanocarriers have been used with natural compounds such as Ginkgo Biloba as well as targeted drugs for neurodegenerative diseases ( 62 – 64 ); these nanoparticles can be organic or inorganic, organic materials (liposomes, micelles, and polymeric nanoparticles) stand out for being compatible and degradable in their entirety. Inorganic nanoparticles (iron oxide nanoparticles, gold nanoparticles, and silica nanoparticles) have smaller size, stability, higher permeability, and a controlled release period ( 65 – 67 ).…”

Ginkgo Biloba and Long COVID: In Vivo and In Vitro Models for the Evaluation of Nanotherapeutic Efficacy

“…The clinical translation of free antioxidant drugs may be hampered by several issues related to drug delivery efficacy. These problems include low drug bioavailability, low permeability through the CNS, limited half-life, and toxicity [ 180 ] ( Figure 7 ). Significant efforts have been made to increase the clinical efficacy of both natural and synthetic antioxidants by using drug delivery systems to overcome their drawbacks.…”