A Review on Liposomes as a Drug Delivery System

Nanoparticle systems have been perceived as the ultimate goal for effective drug delivery for decades. The ideal nanoparticle carries the drug-load safely to a predefined target. There, it is capable of releasing its cargo intracellular or in the extracellular space where the drug can be directly internalized and exert the desired action. Enroute, the nanoparticle prevents unwanted interactions of the drug-load with non-target tissues and where needed, it will enhance the circulation time of the encapsulated drug and enable sustained release. In this context, liposomes, a class of synthetic lipid nanoparticles have been explored in depth. Liposomes are microscopic self-assembling unilamellar or multilamellar vesicles made up of phospholipid bilayer. Both the hydrophilic and hydrophobic drugs can be attached to the lipid bilayer of liposomes and can show their efficacy in the target cell of the human body. Liposomes can significantly alter the pharmacokinetics of drugs. They have been investigated for diverse applications such as treatment of cancer, delivery of gene and vaccine, treatment of lung and skin diseases, treatment of tumours, and imaging tumours at the site of infection. They are leading present-day smart delivery systems due to their flexible biophysical and physicochemical properties, which permit easy control to address different delivery concerns. This review will discuss various advances and updates in liposome-assisted drug delivery and the current clinical use of liposomes for biomedical applications.