Curcumin nanomedicine: a road to cancer therapeutics

Abstract

Cancer is the second leading cause of death in the United States. Conventional therapies cause widespread systemic toxicity and lead to serious side effects which prohibit their long term use. Additionally, in many circumstances tumor resistance and recurrence is commonly observed. Therefore, there is an urgent need to identify suitable anticancer therapies that are highly precise with minimal side effects. Curcumin is a natural polyphenol molecule derived from the Curcuma longa plant which exhibits anticancer, chemopreventive, chemo- and radio-sensitization properties. Curcumin's widespread availability, safety, low cost and multiple cancer fighting functions justify its development as a drug for cancer treatment. However, various basic and clinical studies elucidate curcumin's limited efficacy due to its low solubility, high rate of metabolism, poor bioavailability and pharmacokinetics. A growing list of nanomedicine(s) using first line therapeutic drugs have been approved or are under consideration by the Food and Drug Administration (FDA) to improve human health. These nanotechnology strategies may help to overcome challenges and ease the translation of curcumin from bench to clinical application. Prominent research is reviewed which shows that advanced drug delivery of curcumin (curcumin nanoformulations or curcumin nanomedicine) is able to leverage therapeutic benefits by improving bioavailability and pharmacokinetics which in turn improves binding, internalization and targeting of tumor(s). Outcomes using these novel drug delivery systems have been discussed in detail. This review also describes the tumor-specific drug delivery system(s) that can be highly effective in destroying tumors. Such new approaches are expected to lead to clinical trials and to improve cancer therapeutics.

Fig. 1

Commercially available and proposed curcumin formulations to improve bioavailability and activity.

Fig. 2

Basic and clinical significance of curcumin and nanocurcumin formulations in the field of medicine over a ten-year period. The number of peer-reviewed publications was collected using PubMed (data was collected for the 10 year period from Jan. 2001–Dec. 2011).

Fig. 3

Various clearance mechanisms of curcumin nanoformulations based on their physico-chemical properties. Note: Reticuloendothelial system (RES) is an older term for mononuclear phagocyte system.

Fig. 4

Schematic representation of targeted approach of curcumin nanoformulations for cancer treatment.

Fig. 5

Schematic flow chart delineates the step by step process for the selection of curcumin nanoformulations for clinical applications.

Fig. 6

Magnetic curcumin nanoformulations for theranostic and multi-functional applications.