The Significance of Nanomedicine in Brain-Targeted Drug Delivery: Crossing Blood-Brain Barriers

Abstract

Last two decades have seen a tremendous and fascinating advancement in the field of drug development. Despite the progression in the scientific technology, the diseases of central nervous system (CNS) present a formidable challenge to the clinicians. Prospects to improve quality of life and halt or ameliorate age-related neurodegenerative diseases like Dementia, Alzheimer’s, Parkinson’s etc. are still far to measure. At present, around 1.5 billion people worldwide are suffering from one or another CNS disease [1]. As reviewed in 2017, around 47.5 million people around the globe are living with dementia. The prevalence of dementia is anticipated to be 75.63 million in 2030, reaching to 135.46 million by 2050, which is higher than original number estimated in the 2009 World Alzheimer report [2]. Specifically, in US about 5.2 million people are suffering from Alzheimer’s disease (AD), which has been cited as the sixth leading cause of death, and ranked fifth among those aged 65 years and older. Unless medical breakthroughs are made to favor the pharmacokinetics and pharmacodynamics of experimental therapeutics, it is estimated that by 2050, the number of AD patients may nearly triple from 5 million to a projected 14 million [3,4]. Of the all CNS related diseases, brain tumor is among the most challenging and lethal. Updated in January 2017, nearly 700,000 people in U.S. are living with CNS related tumor. It is estimated that nearly 80,000 cases of primary brain tumor would be diagnosed by the end of 2017. One third of the 32% of the diagnosed cases are anticipated to be malignant, and nearly 53,000 will be non-malignant. Sadly, by the end of 2017, nearly 17,000 people with CNS brain tumor will lose their battle with life [5]. Regardless of the scientific researches and technologies, no effective therapies are out in clinic for most of the brain tumors. The failure of vast majority of novel and current experiential therapeutics to reach/target the brain at a reasonable effective dose remains a major challenge. Despite great stride in understanding of the brain biology, from cellular to behavioral levels, the advances in basic science have not yet been fully developed in an interdisciplinary way, and a definitive translation from bench to bedside is still uncertain [6]. The scope of current communication focuses current challenges in brain-drug delivery, and significance of nanomedicine in crossing BBB, their downside and future prospects are also discussed.