Drug Delivery Systems, CNS Protection, and the Blood Brain Barrier

Abstract

Present review highlights various drug delivery systems used for delivery of pharmaceutical agents mainly antibiotics, antineoplastic agents, neuropeptides, and other therapeutic substances through the endothelial capillaries (BBB) for CNS therapeutics. In addition, the use of ultrasound in delivery of therapeutic agents/biomolecules such as proline rich peptides, prodrugs, radiopharmaceuticals, proteins, immunoglobulins, and chimeric peptides to the target sites in deep tissue locations inside tumor sites of brain has been explained. In addition, therapeutic applications of various types of nanoparticles such as chitosan based nanomers, dendrimers, carbon nanotubes, niosomes, beta cyclodextrin carriers, cholesterol mediated cationic solid lipid nanoparticles, colloidal drug carriers, liposomes, and micelles have been discussed with their recent advancements. Emphasis has been given on the need of physiological and therapeutic optimization of existing drug delivery methods and their carriers to deliver therapeutic amount of drug into the brain for treatment of various neurological diseases and disorders. Further, strong recommendations are being made to develop nanosized drug carriers/vehicles and noninvasive therapeutic alternatives of conventional methods for better therapeutics of CNS related diseases. Hence, there is an urgent need to design nontoxic biocompatible drugs and develop noninvasive delivery methods to check posttreatment clinical fatalities in neuropatients which occur due to existing highly toxic invasive drugs and treatment methods.

Nanoparticles for Brain-Specific Drug and Genetic Material delivery, Imaging and Diagnosis

“…CNTs are graphite sheets rolled into single or multiwalled tubes with a diameter between 0.5-20 nm and a length of 1.5-5000 nm [74]. Due to their inherent properties, these nanomaterials are playing an increasing role in different fields of nanomedicine, including the delivery of drugs, genes, vaccines and also in thermotherapy of tumors due to their thermal conductivity [75].…”

Nanomedicine in Central Nervous System (CNS) Disorders: A Present and Future Prospective

“…30,31 Transferrin and insulin receptors are commonly found on the BBB.32 Hence, the drug adjoins with the ligand of these receptors might transport drugs to the targeted brain area. In the case of transporter mediated delivery, the drug needs to mimic to the endogenous carrier substrate.…”

“…29 Strategies of drug delivery in brain BBB acts as a capillary endothelial interface, that facilitates transport of essential chemical and ion to the brain. 30 Crossing BBB is always a key obstacle for drug delivery system. Hydrophilic molecules reported transferring via specific carrier-mediated endocytosis, transporter, and paracellular pathway.…”

“…31,32 BBB disruption for drug delivery performs via breaking down the tight junction of endothelial cells. 31,33 This can administer through osmotic disruption 30,34,35 or disruptive plasma solutes. 36,37 ICV drug delivery considered as a very poor approach, because the drug transported in the peripheral blood stream, less to the targeted tissues.…”

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“…and for systemic action, it includes treatment for migraine headaches, calcium supplementation, Vitamin B 12 deficiency, pain management 7 . Whereas, targeting brain, for the treatment of various CNS disorders like brain tumours, Alzheimer's disease; epilepsy is an important application of intranasal drug delivery system 8,9 .…”