Engineered Magnetic Polymer Nanoparticles Can Ameliorate Breast Cancer Treatment Inducing Pyroptosis–Starvation along with Chemotherapy

Nanotechnology has shown a revolution in cancer treatments, including breast cancers. However, there remain some challenges and translational hurdles. Surgery, radiotherapy, and chemotherapy are the primary treatment methods for breast cancer, although drug combinations showed promising results in preclinical studies. Herein we report the development of a smart drug delivery system (DDS) to efficiently treat breast cancer by pyroptosis-starvation-chemotherapeutic combination. Cancer-starvation agent glucose oxidase was chemically attached to synthesized iron oxide nanoparticles which were entrapped inside poly(lactic-co-glycolic acid) along with apoptosis-associated speck-like protein containing a caspase recruitment domain plasmid and paclitaxel (PTX). An emulsion solvent evaporation method was used to prepare the DDS. The surface of the DDS was modified with chitosan to which aptamer was attached to achieve site-specific targeting. Hence, the prepared DDS could be targeted to a tumor site by both external magnet and aptamer to obtain an enhanced accumulation of drugs at the tumor site. The final size of the aptamer-decorated DDS was less than 200 nm, and the encapsulation efficiency of PTX was 76.5 ± 2.5%. Drug release from the developed DDS was much higher at pH 5.5 than at pH 7.4, ensuring the pH sensitivity of the DDS. Due to efficient dual targeting of the DDS, in vitro viability of 4T1 cells was reduced to 12.1 ± 1.6%, whereas the nontargeted group and free PTX group could reduce the viability of cells to 29.2 ± 2.4 and 46.2 ± 1.6%, respectively. Our DDS showed a synergistic effect in vitro and no severe side effects in vivo. This DDS has strong potential to treat various cancers.