P-Sulfocalix[6]arene as Nanocarrier for Controlled Delivery of Doxorubicin

Given the high toxicity of the anthracycline antibiotic called doxorubicin (DOX), it is relevant to look for nanocarriers that, decreasing the side effects of the drug, were able to transport it towards a therapeutic target. Accordingly, the encapsulation of DOX by p-sulfocalix[6]arene (calix) has been studied. The interaction of DOX with the macrocycle, as well as with DNA, has been investigated and the equilibrium constant for each binding process estimated. Results showed that the binding constant of DOX to DNA, KDNA, is three orders of magnitude higher than that to calix, Kcalix. A multidisciplinary study has been done to demonstrate the ability of calixarenes to encapsulate DOX molecules, as well as the power of the DOX molecules included into the inner cavity of the macrocycle to bind with the DNA. Citotoxicity measurements were done in different cancer and normal cell lines to probe the decrease in the toxicity of the encapsulated DOX, demonstrating thus the decrease of its side effects in the human organism. The low toxicity of calixarenes has also been demonstrated for different cell lines.