Combination of magnetic targeting with synergistic inhibition of NF-κB and glutathione via micellar drug nanomedicine enhances its anti-tumor efficacy

Breast cancer is not only one of the most prevalent types of cancer, but also it is a prime cause of death in women aged between 20 and 59. Although chemotherapy is the most common therapy approach, multiple side effects can result from lack of specificity and the use of overdose as safe doses may not completely cure cancer. Therefore, we aimed in this study is to combine the merits of NF-κB inhibiting potential of celastrol (CST) with glutathione inhibitory effect of sulfasalazine (SFZ) which prevents CST inactivation and thus enhances its anti-tumor activity. Inspired by the CD44-mediated tumor targeting effect of the hydrophilic polysaccharide chondroitin sulphate (ChS), we chemically synthesized amphiphilic zein-ChS micelles. While the water insoluble SFZ was chemically coupled to zein, CST was physically entrapped within the hydrophobic zein/SFZ micellar core. Moreover, physical encapsulation of oleic acid-capped SPIONs in the hydrophobic core of micelles enabled both magnetic tumor targeting as well as MRI theranostic capacity. Combining magnetic targeting to with the active targeting effect of ChS resulted in enhanced cellular internalization of the micelles in MCF-7 cancer cells and hence higher cytotoxic effect against MCF-7 and MDA-MB-231 breast cancer cells. In the in vivo experiments, magnetically-targeted micelles (154.4 nm) succeeded in achieving the lowest percentage increase in the tumor volume in tumor bearing mice, the highest percentage of tumor necrosis associated with significant reduction in the levels of TNF-α, Ki-67, NF-κB, VEGF, COX-2 markers compared to non-magnetically targeted micelles-, free drug-treated and positive control groups. Collectively, the developed magnetically targeted micelles pave the way for design of cancer nano-theranostic drug combinations.

Keywords: NF-κB targeting; dual targeting; glutathione targeting; magnetic targeting; micellar nanomedicine; synergistic cancer therapy; theranostic nanoparticles.