Blood–brain barrier and laser technology for drug brain delivery

Here,we discuss an important problem in medicine as development of efctive strategies for brain drug delivery.This problem is related to the blood-brain barrier(BBB),which is a“customs”controlling the entrance of different molecules from blood into the brain protecting the normal function of central nervous system(CNS).We show three interfaces of anatomical side of BBB and two functional types of BBB一physical and transporter barriers.Although this protective mechanism is essential for health of CNS,it also creates a hindrance to the entry of drugs into the brain.The BBB was discovered over 100 years ago but till now,there is no efective methods for brain drug delivery.There ane more than 70 approaches for overcoming BBB incuding physical,chenical and biological techniques but all of these tools have limitation to be widely used in clinical practice due to invasi venes,challenge in performing,very costly or lim-itation of drug concentration.Photodynamic therapy(PDT)is usual clinical method of surgical navigation for the resection of brain tumor and anti-cancer therapy.Nowadays,the application of PDT is considered as a potential promising tool for brain drug delivery via opening of BBB.Here,we show the first sucoessful experimental results in this field discussing the adventures and disadv antages of PDT-related BBB disruption as well as altematives to overcome these limitations and possi ble mechanisms with new pathways for brain clearance via gly mphatic and lymphatic systems.