Theranostic applications in multiple sclerosis: Nanomedicines through nasal route Available to Purchase

Most of the central nervous system (CNS) disorders have always been perceived as challenging pathologies, which is generally attributed to the presence of the formidable blood-brain barrier (BBB). Multiple Sclerosis (MS) is one of such CNS disorders that affect young adults. MS is an autoimmune, neurodegenerative, non-traumatic disease that leads to disability and is characterized by chronic inflammation, local demyelination, scars involving a dense fibrous network of neuroglial cells, destruction of axons, and significant immune cell infiltration. Though various neuroprotective drugs are available for its treatment, its complete reversal is generally not possible due to the failure of conventional approaches to deliver the drug precisely. Thus, there is a need to develop novel strategies for drug delivery to treat MS effectively. Delivery of drug to brain via nose is a non-invasive way that delivers the drug through trigeminal and olfactory pathways, thereby circumventing the blood-brain barrier. Moreover, drug degradation as well as the loss associated with systemic clearance is also reduced which leads to enhanced drug concentration in the brain and results in dose reduction. However, nasal drug delivery systems are associated with certain limitations like variable drug permeation through the nasal mucosa and mucociliary clearance. Various drug delivery approaches (nano-drug carriers, mucoadhesive devices, prodrugs, etc.) have been explored to overcome these issues and target the brain through intranasal administration. Although there is considerable progress in nasal delivery of nanomedicines for treating CNS-related disorders, very little is known regarding their potential in MS. The current manuscript highlights the pathophysiology of MS, mechanism involved in drug delivery from nose to brain, application of nanomedicines in the diagnosis and treatment of MS, the animal models for the evaluation of in vivo potential, and the research done till date.