Ferroptosis amplified by a tumor-targeted artesunate nano-derivative for effective colon cancer treatment

Background: Artesunate (ART), a proven antimalarial drug, is promising but has limited antitumor activity because of its poor stability, low potency, and lack of tumor selectivity. While its effect is linked to ferroptosis, an iron-dependent form of cell death driven by lipid peroxidation, clinical translation in oncology requires enhanced drug delivery and targeting. We hypothesized that engineering a tumor-targeted nanoparticle of an ART prodrug could amplify ferroptosis induction and therapeutic efficacy against colorectal cancer (CRC). Methods: We systematically designed and synthesized six amino acid-modified ART derivatives. The most potent conjugate was further functionalized with 3-aminophenylboronic acid (PBA) to create the final prodrug, AAP. AAP self-assembled into nanoparticles (AAP NPs) via a one-step precipitation method. The size, PDI, and morphology of the NPs were characterized. Efficacy was evaluated in multiple CRC cell lines (CT26, HCT116, SW480, SW620) and a hepatoma cell line (Huh7) via CCK-8 assays. Cellular uptake was visualized via coumarin-6-loaded NPs. The antitumor effect, systemic safety, survival benefit, and mechanism of AAP NPs were comprehensively investigated in a BALB/c mouse model bearing CT26 tumors. Results: AAP demonstrated superior in vitro cytotoxicity compared with native ART, with IC50 values 1.77- to 2.09-fold lower across CRC and hepatoma cells. The resulting AAP NPs were monodisperse spheres with a uniform size of 174.44 ± 9.97 nm and a low PDI of 0.046. Compared with ART or ART-AA (no PBA), the completed AAP NPs exhibited significantly stronger, dose- and time-dependent cytotoxicity against all cancer cells tested (P < 0.05) and were effectively internalized by CT26 cells. In vivo, AAP NPs achieved the most potent tumor growth inhibition, reducing the tumor volume and weight to 531.29 ± 132.20 mm³ and 483.14 ± 118.91 mg, respectively, significantly outperforming the control, ART, and ART-AA NP groups (P < 0.05). Critically, AAP NPs significantly prolonged mouse survival (P < 0.05) . Mechanistically, AAP NP treatment led to significant accumulation of ROS in tumor tissues, confirming the induction of ferroptosis. Conclusion: We developed a dual-targeted ART nanoprodrug that leverages PBA-mediated active targeting and the EPR effect. This strategy potently inhibits CRC growth by triggering ferroptosis and exhibits an excellent safety profile, offering a compelling approach to repurpose ART for targeted cancer therapy.