Methotrexate-conjugated to polymer quantum dot for cytotoxicity effect improved against MCF-7 and Hela cells

Abstract

Methotrexate (MTX) is a folic acid derivative that is used for the treatment of different malignancies, whose applications have become limited by its toxic dose-related side effect and the possible initiation of drug resistance. The aim of the present research is to study the enhancement of the cellular cytotoxicity of MTX as an anticancer drug by conjugation to the synthesized polymer dots' (Pdots) surface. This conjugation was developed covalently by carbodiimide chemistry and characterized with Fourier transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS), and UV-Vis spectroscopy. As follows, antineoplastic effect of these synthesized Pdot-MTX nanoconjugates against human breast cancer, Michigan Cancer Foundation-7 (MCF-7), and human cervical (HeLa) cancer cells was investigated and compared with bare MTX and Pdots. The half maximal inhibitory concentration (IC50) of the Pdot-MTX nanoconjugates and the free MTX molecules was obtained 20 and 30 A mu g mL(-1), respectively in the HeLa cells; whereas, these values were about 15 and 25 A mu g mL(-1) for the Pdot-MTX nanoconjugates and the free MTX in the MCF-7 cells. In fact, the conjugation of Pdots with singular properties to MTX enhanced the cellular cytotoxicity of MTX through folate receptors (FRs)-mediated endocytosis that circumvents the efflux functions of cancerous cells. Accordingly, conjugated Pdots with MTX might offer superior hopes for cancer therapeutics and diagnosis as a novel application in future that is of great importance in the fields of drug discovery and chemical biology.