Precise Carrier-Free Pt(IV)-Nanobombs for Apoptosis/Ferroptosis Synergistic Tumor Therapy: A New Effective Method to Obtain Good Chemotherapy and Low Toxicity.

The emerged apoptosis/ferroptosis synergistic platinum-based therapy has attracted a lot of attention but is far from clinic use due to high systemic toxicity. Herein, a series of novel precise carrier-free self-assembled platinum(IV) nanoparticles with lipid regulation effect named FSPNPs (NPs-NPs) were constructed via connecting fenofibrate acid (FA) to cisplatin or oxaliplatin-derived platinum(IV)-intermediates with disulfide bonds. FSPNPs can be stimulated by high-glutathione/ascorbic acid and acidity environment to produce an "explosion-like" cascade release process. Cell-activity showed precision of FSPNPs, which accumulated more in tumor cells and inhibited cell proliferation. Especially, NPs have higher cell selectivity than cisplatin. FSPNPs downregulated glutathione/glutathione peroxidase 4, increased reactive oxygen species/lipid peroxidation/malondialdehyde, induced DNA damage/S-phase arrest, and regulated p53/Bcl-2/Bax to trigger the apoptosis/ferroptosis hybrid pathway. The released FA and derivates were docked into the peroxisome proliferator-activated receptor α with activating cholesterol metabolism to destroy membrane integrity. FSPNPs also showed good biocompatibility and superior antitumor activity with no observable tissue damage.