Abstract:
Malignant glioma is the most prevalent and deadly form of brain cancer. Currently available non-surgical therapies for brain glioma, including chemotherapy and radiotherapy are associated with high tumour resistance, lack of specificity and toxicity. Boron Neutron Capture Therapy (BNCT) is a promising alternative to these conventional therapies, which allows a targeted tumour treatment. The success of BNCT is mainly dependent on the selective and targeted delivery of sufficient quantities of boron atoms to tumour cells which minimises effects on normal tissues. The entry of boron atoms, however, is limited by the blood-brain barrier and the clinically approved boron compounds; including boronophenylalanine, sodium borocaptate, and disodium-decahydro-closo-decaborate, do not satisfy all the criteria. Nano-sized delivery systems have been developed to increase the quantity of boron delivered, and enhance selective tumour targeting as well as blood-brain barrier penetration. Among these nanocarriers, liposomes are an attractive carrier for tumour targeting due to their excellent biocompatibility and ease for surface modification to confer biological functions. This chapter will focus on various liposomal delivery systems that are currently being explored to overcome the anatomical and physiological obstacles to improve the delivery efficiency of BNCT to brain glioma cells. Systems include conventional PEGylated liposomes, boron containing lipid embedded liposomes and ligand-functionalised liposomes. The chapter will also provide a survey on in vitro and in vivo models for evaluation of BNCT efficacy which are required to ensure the successful translation. Lastly, future perspectives in clinical applications of liposomes as drug delivery systems for BNCT will be discussed.