Tumor targeting and brain specific delivery and strategies: A review

Abstract

Brain tumors represent one of the most challenging  and difficult areas in unmet medical  needs. Tumor- targeted  and brain drug delivery systems,  increase drug accumulation  in the tumor region, and also reduce toxicity in normal brain and peripheral tissue, are a promising new approach to brain tumor treatments. When brain-tumors  exhibit  numerous  notable  characteristics  relative  to  tumors  growing  in  peripheral  tissues, potential  targets  based on continuously  changing  vascular  characteristics  and the microenvironment  can be utilized to facilitate effective brain tumor-targeted drug delivery. In present review, we briery describe the physiological characteristics of brain tumors, including blood–brain/brain tumor barriers, the tumor microenvironment, and tumor stem cells. We are also discussing in review targeted delivery strategies and introduce a systematic targeted drug delivery strategy to overcome the challenges. A disturbing fact about the delivery of drugs to the CNS in the presence of a blood-brain barrier that has a tendency to impair the drug distribution and denotes the general barrier for the development of CNS drugs. Neuro-peptides and many more drugs which  are hydrophilic  in nature possibly will  encompass  the intricacy while passing the blood-brain barrier. The net amount of delivered drugs and their capability to gain access to the pertinent target sites are the main considering points for CNS drug development. In this review, we will discuss about methodologies for targeting site of brain.