Intelligent drug delivery systems for the treatment of solid tumors

Abstract

The rationale for the use of nanoparticle formulations to treat cancer is based on the ability of these particles to facilitate selective delivery of drugs to the tumor site, reducing adverse effects and improving therapeutic outcomes. Current clinically approved nanomedicines have managed to reduce adverse effects significantly but the increase in overall survival is modest in many cases. Therefore, even though the goal of a better quality of life for the cancer patients has been achieved in large part, the increase in life expectancy still remains a critical challenge. Abnormalities in the tumor micro-environment prevent homogeneous distribution of nanoparticles to the interior of the tumor, decreasing the efficacy of the drug. Intelligent drug delivery systems offer new hope for overcoming these physiological barriers posed by the tumor and have the potential to provide more effective treatments. This review discusses the barriers to the delivery of nanomedicines to solid tumors, suggests design considerations that could optimize delivery and reviews promising intelligent drug delivery systems that have been developed to date.