Lipid Nanocarriers for Neurotherapeutics: Introduction, Challenges, Blood-brain Barrier, and Promises of Delivery Approaches

Abstract

: Significant efforts are being made in research to discover newer neurotherapeuticals, but the rate of reported neurological disorders has been increasing at an alarming speed. Neurothera-peuticals delivery in the brain is still posing a significant challenge, owing to the blood-brain barrier and blood-cerebrospinal fluid barrier. These physiological barriers restrict the passage of systemically available fractions of neurotherapeuticals into the brain, owing to low permeability and drug localization factors. Neurotherapeuticals encapsulating lipid carriers favor a significant increase in bioavailability of poorly water-soluble drugs by enhancing solubility in the gastroin-testinal tract and favoring stability. Due to their small size and lipid-based composition, these carriers offer enhanced permeability across the semi-permeable blood-brain barrier to effective-ly transport encapsulated loads, such as synthetic drugs, nutraceuticals, phytoconstituents, herb-al extracts, and peptides, reducing incidences of off-target mediated adverse impacts and tox-icity. The most significant advantage of such lipid-based delivery systems is non–invasive na-ture and targeting of neurotherapeuticals to the central nervous system. Critical attributes of li-pid-based carriers modulate release rates in rate-controlled manners, enable higher penetration through the blood-brain barrier, and bypass the hepatic first-pass metabolism, leading to higher CNS bioavailability neurotherapeuticals. The current review discusses a brief and introductory account of the limitations of neurothera-peuticals, pharmacological barriers, challenges in brain-targeted delivery, and the potential of nanotechnology-processed lipid-based carriers in the clinical management of neuronal disor-ders.

Advances in Nanotechnology for Enhancing the Solubility and Bioavailability of Poorly Soluble Drugs

“…These innovative formulations highlight the progressive role of liposomes in nanotechnology-based therapeutics. 50 , 51 …”

“…These innovative formulations highlight the progressive role of liposomes in nanotechnology-based therapeutics. 50,51 Liposomal nanocarriers are primarily categorized into Solid Lipid Nanoparticles (SLNs) and Nanostructured Lipid Carriers (NLCs), as illustrated in Figure 2B. SLNs, with particle sizes ranging from 50 to 1000 nm, are solid colloidal drug delivery systems.…”

An Overview on the Physiopathology of the Blood–Brain Barrier and the Lipid-Based Nanocarriers for Central Nervous System Delivery

“…Thanks to the many advances in nanotechnology, nanomedicine has a wide array of organic, inorganic, or NCs for therapeutic applications [94,95]. Among the organic NCs, those that seem to be most used for brain drug delivery are the lipid-based ones, that is, liposomes, SLNs, NEs, NLCs, niosomes, proniosomes, cubosomes, EVs, cell membranederived nanocarriers, and organic nanocarriers with high lipophilicity and ability to cross the BBB through passive diffusion [86,96].…”

Temozolomide Efficacy and Metabolism: The Implicit Relevance of Nanoscale Delivery Systems

“…Other types of nanotransporters are solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) [ 66 , 67 ]. SLNs are aqueous colloidal dispersed particles consisting of a solid lipid core stabilized by surfactants.…”