Smart thermo/pH responsive magnetic nanogels for the simultaneous delivery of doxorubicin and methotrexate

Abstract

Two novel dual temperature/pH-sensitive superparamagnetic nanogels were developed with the aim of simultaneously delivering two different anticancer drugs, doxorubicin (DOX) and methotrexate (MTX). The studied copolymers were characterized by H-1 NMR, SEM, and FTIR spectroscopy. Morphological investigations showed that both blank and drug-loaded nanogels had uniform shapes with a mean diameter of less than 30 nm. The drug storage/release behaviors were investigated. The nanogels showed an encapsulation efficiency of about 95% for both drugs. The cumulative in vitro release of the DOX/MTX-loaded nanogels exhibited an apparent thermo/pH-triggered controlled drug release in a sustained manner that was able to distinguish between tumor tissues. The cytotoxicity assay of a blank carrier to MCF7 and MDA-MB-231 cell lines indicated that the nanogels were suitable as drug carriers. Cell viability experiments further confirmed that the co-administration of DOX with MTX had a superior cytotoxicity to the mentioned cells compared with free dual drug-or single drug-loaded forms. Therefore, dual anticancer drug-loaded thermo/pH-sensitive nanogels have the potential to be used for cancer therapy, because they maintain a low premature drug release during blood circulation while having a rapid release upon reaching tumorous tissue. (C) 2015 Elsevier B.V. All rights reserved.