Barriers to Targeted Drug Delivery Strategies in Brain

Brain tumor is considered to be the most detrimental disease found in humans. Amongst the various brain tumors, glioblastoma has emerged as a highly invasive malignant disease that has contributed to significant mortality worldwide. Despite surgical and drug innovations, most of the patients suffering from brain tumours have shown poor prognosis, with a median life span. The presence of the blood-brain barrier (BBB) acts as a protective layer outside the brain for most of the conventional, diagnostic and therapeutic agents, which in turn leads to poor diagnosis and less efficacy in most clinical subjects. In recent years, multifunctional nanotechnology systems have been employed to deliver theranostic agents to the brain, showing promising outcomes in the treatment of various forms of cancer. The present chapter provides comprehensive information on the most recent developments in BBB-crossing nanotechnology, with a slight focus on the thoughtful design of multifunctional nanoplatforms for effective BBB penetration, accurate tumor imaging, and substantial brain tumor inhibition. Besides, various physiological barriers and transportation mechanisms, different drug delivery systems for brain tumors are also highlighted. Furthermore, major advancements in brain tumor theranostics pertaining to employing different nanosystems such as liposomes, polymeric nanoparticles, bio-nano particles, and inorganic-nanoparticles for effective nano-drug delivery for theranostics in brain tumors have also been discussed.