Nano carriers for drug transport across the blood–brain barrier

Abstract

Effective therapy lies in achieving a therapeutic amount of drug to the proper site in the body and then maintaining the desired drug concentration for a sufficient time interval to be clinically effective for treatment. The blood-brain barrier (BBB) hinders most drugs from entering the central nervous system (CNS) from the blood stream, leading to the difficulty of delivering drugs to the brain via the circulatory system for the treatment, diagnosis and prevention of brain diseases. Several brain drug delivery approaches have been developed, such as intracerebral and intracerebroventricular administration, intranasal delivery and blood-to-brain delivery, as a result of transient BBB disruption induced by biological, chemical or physical stimuli such as zonula occludens toxin, mannitol, magnetic heating and ultrasound, but these approaches showed disadvantages of being dangerous, high cost and unsuitability for most brain diseases and drugs. The strategy of vector-mediated blood-to-brain delivery, which involves improving BBB permeability of the drug-carrier conjugate, can minimize side effects, such as being submicrometre objects that behave as a whole unit in terms of their transport and properties, nanomaterials, are promising carrier vehicles for direct drug transport across the intact BBB as a result of their potential to enter the brain capillary endothelial cells by means of normal endocytosis and transcytosis due to their small size, as well as their possibility of being functionalized with multiple copies of the drug molecule of interest. This review provids a concise discussion of nano carriers for drug transport across the intact BBB, various forms of nanomaterials including inorganic/solid lipid/polymeric nanoparticles, nanoemulsions, quantum dots, nanogels, liposomes, micelles, dendrimers, polymersomes and exosomes are critically evaluated, their mechanisms for drug transport across the BBB are reviewed, and the future directions of this area are fully discussed.

A microfluidic model of the blood–brain barrier to study permeabilization by pulsed electric fields

“…Advanced drug delivery methods are being widely investigated to enhance transport across the BBB including focused ultrasound 7–9 , osmotic disruption 10 , drug delivery vehicles 11–14 , and pulsed electric fields (PEFs) 15–17 . Although all these techniques have inherent advantages and disadvantages, PEFs may offer advantages over other techniques due to their synergistic potential for treating a variety of CNS disorders.…”

Technology and Dementia: The Future is Now

“…Future directions in dementia therapy are predicted to include nanotechnology either to “repair” brain damage [89] or for drug delivery [90]. While there are still many obstacles to resolve, work on nanoparticle and implantable therapeutics to locally deliver chemotherapy for treating brain tumours [91], opens up huge possibilities for delivering new types of interventions for people either with dementia or ideally, before dementia develops.…”

Extracellular vesicles as emerging targets in cancer: Recent development from bench to bedside

“…The advantage in size enables better biodistribution and bioavailability of exosomes in the human body. Escape of lung clearance and permeability across the blood-brain barrier were reported for exosome-based drug carriers (200, 254). In addition, exosomes could achieve targeted delivery compared to synthetic nanoparticles.…”