Sodium alginate-based dual-responsive nanoparticles co-loaded with baicalin and doxorubicin induce ferroptosis in hepatocellular carcinoma associated with the PI3K/AKT/FoxO3α axis regulation.

BACKGROUND: Hepatocellular carcinoma (HCC) has high malignancy, poor prognosis, and frequent chemo-resistance. Doxorubicin (DOX) has strong anti-tumor activity but severe systemic toxicity; baicalin (BAI) acts against HCC yet has poor solubility and low bioavailability. Marine sodium alginate (SA) is a biocompatible carrier for responsive nanomedicines. We fabricated pH/GSH dual-responsive SA nanoparticles co-loaded with BAI and DOX (DOX/BAI NPs), tested synergistic anti-HCC activity, and verified the correlation between the PI3K/AKT/FOXO3α axis and DOX/BAI NPs-induced ferroptosis. METHODS: Amphiphilic SA-SS-BAI was synthesized via cystamine disulfide bonds and self-assembled to encapsulate DOX. We characterized physicochemical traits, dual responsiveness, stability, and drug release. HepG2 cell uptake, endocytosis, and cytotoxicity were measured. Ferroptosis markers (ROS, Fe2+, GSH, MDA, SLC7A11, GPX4) were quantified. Western blot detected PI3K/AKT/FOXO3α activity, with SC79 rescue for mechanistic validation. Pharmacokinetics, anti-tumor efficacy and biosafety were evaluated in H22 tumor-bearing mice. RESULTS: SA-SS-BAI-4 formed uniform ∼148 nm spherical DOX/BAI NPs with good loading and encapsulation. NPs stayed stable physiologically and disassembled rapidly under low pH plus high GSH. Caveolae-dependent uptake was greatly boosted in HepG2 cells, yielding stronger growth inhibition than free drugs or physical mixtures. NPs triggered robust ferroptosis via ROS/Fe2+ buildup, elevated MDA level, GSH loss, and reduced SLC7A11/GPX4. NPs treatment inhibited PI3K/AKT/FOXO3α phosphorylation; SC79 reversed ferroptosis, confirming the correlative regulatory relationship of this pathway. In vivo, NPs extended drug circulation, slowed H22 tumor growth, and markedly alleviated DOX-elicited hepatic and myocardial injury. CONCLUSION: This dual pH/GSH-responsive SA DOX/BAI nanoplatform exerts synergistic anti-HCC effects by inducing ferroptosis, which is associated with PI3K/AKT/FOXO3α axis suppression. The marine polysaccharide carrier overcomes BAI and DOX solubility/toxicity defects, creates a practical HCC combinatorial nanotherapy, and defines a potential correlation between the PI3K/AKT/FOXO3α regulatory axis and hepatic cancer ferroptosis.