Nanoparticle-Based Technology Approaches to the Management of Neurological Disorders

Abstract

Neurological disorders are the most devastating and challenging diseases associated with the central nervous system (CNS). The blood-brain barrier (BBB) maintains homeostasis of the brain and contributes towards the maintenance of a very delicate microenvironment, impairing the transport of many therapeutics into the CNS and making the management of common neurological disorders such as Alzheimer’s disease (AD), Parkinson’s disease (PD), cerebrovascular diseases (CVDs) and traumatic brain injury (TBI), exceptionally complicated. Nanoparticle (NP) technology offers a platform for the design of tissue-specific drug carrying systems owing to its versatile and modifiable nature. The prospect of being able to design NPs capable of successfully crossing the BBB, and maintaining a high drug bioavailability in neural parenchyma, has spurred much interest in the field of nanomedicine. NPs, which also come in an array of forms including polymeric NPs, solid lipid nanoparticles (SLNs), quantum dots and liposomes, have the flexibility of being conjugated with various macromolecules, such as surfactants to confer the physical or chemical property desired. These nanodelivery strategies represent potential novel and minimally invasive approaches to the treatment and diagnosis of these neurological disorders. Most of the strategies revolve around the ability of the NPs to cross the BBB via various influx mechanisms, such as adsorptive-mediated transcytosis (AMT) and receptor-mediated transcytosis (RMT), targeting specific biomarkers or lesions unique to that pathological condition, thereby ensuring high tissue-specific targeting and minimizing off-target side effects. In this article, insights into common neurological disorders and challenges of delivering CNS drugs due to the presence of BBB is provided, before an in-depth review of nanoparticle-based theranostic strategies.

Nanoparticles in Combating Neuronal Dysregulated Signaling Pathways: Recent Approaches to the Nanoformulations of Phytochemicals and Synthetic Drugs Against Neurodegenerative Diseases

“… 130 It is thought that PD has a significant hereditary connection, with mutations in the gene α-synuclein, which encodes for a protein that has been recognized as one of the contributing reasons for the beginning of PD. 20 …”

Traumatic brain injury: Future application of nanomedicine

“…For infiltrating the BBB, the NP carriers are coated with biospecific molecules according to requirements in a process called functionalization. This facilitates targeted delivery in the brain [23]. To ensure entry into the brain NPs are tuned to follow mainly three broad pathways.…”

“…Lastly, the cell-mediated transcytosis involves immune cell dependent uptake, via neutrophils, monocytes and macrophages. This method is exploited to "hitchhike" NPs into the brain [23].…”

Nanoparticles: A Hope for the Treatment of Inflammation in CNS

“…NPs can encapsulate drugs with relatively high drug loading ( Sim et al, 2020 ), and the surface of NPs can be easily manipulated to achieve drug targeting ( Sun et al, 2014 ). In addition, NPs can control the release of drugs at the site of target cells or tissues, thereby increasing therapeutic efficacy and reducing the side effects of drugs.…”