Abstract
Multiple-drug resistance in human cancer is a major problem. To circumvent this issue, clinicians combine several drugs. However, this strategy could backfire resulting in more toxic or ineffective treatments. Carbon nanotubes (CNTs), and particularly multi-walled nanotubes (MWCNTs), display intrinsic properties against cancer interfering with microtubule dynamics and triggering anti-proliferative, anti-migratory and cytotoxic effects in vitro that result in tumor growth inhibition in vivo. Remarkably, these effects are maintained in tumors resistant to traditional microtubule-binding chemotherapies such as Taxol®. In the view of these properties, we investigate the use of MWCNTs in the development of active-by-design nanocarriers, attempting to enhance the effect of broadly-used chemotherapies. We compare the cytotoxic and the anti-tumoral effect of 5-Fluorouracil (5-FU) -an antimetabolite treatment of various forms of cancer- with that of the drug physisorbed onto MWCNTs. Our results demonstrate how the total effect of the drug 5-FU is remarkably improved (50% more effective) when delivered intratumorally coupled to MWCNTs both in vitro and in vivo in solid tumoral models. Our results demonstrate how using MWCNTs as anti-cancer drug delivery platforms is a promising approach to boost the efficacy of traditional chemotherapies, while considerably reducing the chances of resistance in cancer cells.