Managing CNS Tumors: The Nanomedicine Approach

Abstract

Albeit the rapidly evolving knowledge about tumor biochemistry enables various new drug molecules to be designed as treatments, malignant central nervous system (CNS) tumors remain untreatable due to the failure to expose the entire tumor to such therapeutics at pharmacologically meaningful quantities. Therefore, drug delivery in CNS tumors must be properly addressed, as otherwise, novel therapies will continue to fail. In this regard, nanomedicine poses an appealing platform for efficient drug delivery to the CNS, since it may be targeted to improve the drug availability in the site of action, which would be translated into lower drug doses and fewer side effects. Hence, the accumulation of data about the CNS physiology and their relevant receptors, the widening therapeutic armamentarium of drugs potentially useful in CNS chemotherapy and the alternative routes for administration may envisage nanomedicines as a forthcoming routine approach. Indeed, on the basis of the promising results gathered from preclinical studies of nanomedicine-based therapy both systemically and locally administered, some nanomedicines have already been approved for clinical trials in a variety of CNS tumor conditions to serve as the first steps in the translation of nanotherapy to clinic. Their outcome will steer research directions for further improvements.

<strong></strong>Current Status of Nanomedicine in CNS Cancer Therapeutics in the Post-COVID-19 Era

“…Regulatory agencies, including the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA), have established guidelines for the development and approval of nanomedicinebased therapeutics [27]. These guidelines emphasize safety, efficacy, and quality control [27][28][29][30]. Furthermore, international organizations, such as the World Health Organization (WHO), play a role in ensuring equitable access to nanomedicine-based treatments for CNS cancer on a global scale [29,[31][32][33].…”

Smart Nanoformulations for Brain Cancer Theranostics: Challenges and Promises

“…Among the diverse cancer types, brain cancers have one of the lowest incidences; however, they are amongst the most invasive and with the highest mortality rates [ 2 ]. In addition to the excessive rates of recurrence and low survival rates, hindrances to common anti-cancer drugs make brain cancers one of the most dreadful cancers [ 3 ].…”

“…Chemotherapeutics that have improved the prognosis of many other cancers have largely failed against brain tumors, primarily owing to the inability to penetrate the blood brain and blood brain tumor barriers (BBTB) [ 12 , 13 ]. Several other properties of CNS cancers have contributed to the failures of conventional therapeutics and elusiveness of development of an effective therapy, such as their cellular and molecular heterogeneity, immunosuppressive nature and susceptibility to genetic/epigenetic influences [ 2 , 9 ]. Overall, the failures in clinical neuro-oncology call both for a better understanding of the molecular and cellular mechanisms of pathogenesis of brain tumors (and their heterogeneity/plasticity) as well as the design of innovative and insightful treatment/monitoring approaches.…”