Current trends in the development of liposomes for chemotherapeutic drug delivery

Published literature on cancer by health agencies and health organizations reveals increased cancer incidence year by year. The first line of cancer treatment involves one or more modalities which include surgical removal of the tumor, radiation therapy, and chemotherapy. Chemotherapeutic drugs by themselves cannot differentiate the tumor cells and healthy cells. This leads to unwanted damage to the healthy cells and unfavorable bio-distribution of a drug in the body resulting in a suboptimal performance at the desired site of action. In addition, resistance to drugs by cancerous cells due to drug efflux transporters remains to be another major obstacle in the treatment of cancer. Liposomes gained attention as drug carriers in cancer therapy being nonimmunogenic, biocompatible, able to enhance drug solubility, and able to encapsulate a broad range of drugs. Passively targeted liposomes were successful in being translated to clinical use which can be substantiated by commercially available liposomal therapies. However, the translation of active targeted liposomes to patients either has faced shortcomings or is still in the clinical trials and needs to prove effective in clinical settings. This review focuses on liposomes for the treatment of cancer with emphasis on various strategies like passive and active targeting, overcoming multidrug resistance, stimuli-responsiveness, and intracellular delivery of therapeutic agents to the tumorous cells.