Theranostic Liposome for Brain Tumor Diagnosis and Treatment

The treatment of brain tumours is often a challenging task due to the low permeability of drugs through the blood-brain barrier and their poor penetration into the tumour tissues. Liposomes enhance the delivery of chemotherapeutics to the brain without using any invasive approach. Liposomes are biomimetic nanocarriers that exhibit good biocompatibility, high loading capacity, and the ability to reduce the amount of encapsulated drugs. It is a promising candidate performing a dual function of both drug delivery and diagnosis. This approach helps to locate the tumour tissue with appropriate biodistribution of liposomes. The theranostic liposomes provide a platform for imaging tumour cells for early diagnosis and simultaneously, delivery to the brain enhances the targeting delivery. Fluorescent dyes, magnetic resonance imaging, and nuclear imaging are the few approaches used in the diagnosis of tumour cells. A new approach involving semi-conductor-based quantum dots has emerged as an imaging reagent for brain tissues. The theranostic application of liposomes provides the real-time monitoring of the administered drug, reducing the risk of under-or overdosing and allowing for more customized therapy regimens. This chapter highlights the techniques for directing liposomes to solid tumours in-depth, potential targets in cancer cells, such as extracellular and intracellular targets, and targets in the tumour microenvironment or vasculature. Additionally, this chapter also concludes recent efforts for improving anticancer drug delivery at the tumour site using surface functionalization techniques, and the different contrast agents which help in diagnosis are discussed.

Keywords: Liposomes, MRI, Nuclear Imaging, Surface Modification, Theranostics.