Single-walled carbon nanotubes (SWNTs) with unique physicochemical properties have exhibited promising biomedical applications as drug and gene carriers. In this study, polyethylenimine (PEI)-modified SWNT conjugates linked with candesartan (CD) were developed to deliver vascular endothelial growth factor (VEGF)-targeted siRNA (siVEGF) for the synergistic and targeted treatment of tumor angiogenesis. The characterization results revealed that SWNT-PEI-CD conjugates were successfully synthesized and exhibited desirable dispersibility and superior stability. Confocal laser scanning microscopy (CLSM) and flow cytometry (FCM) results showed that SWNT-PEI-CD/siVEGF complexes could achieve high cellular uptake and specific intracellular distribution of siRNA in ATR overexpressed PANC-1 cells. Strong down-regulation of VEGF was also verified by qualitative real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and Western blot in complex-treated PANC-1 cells. The in vitro angiogenesis assay showed that SWNT-PEI-CD/siVEGF complexes highly inhibited tube formation of human umbilical vein endothelial cells. Furthermore, in vivo observation in PANC-1 xenografted nude mice demonstrated that SWNT-PEI-CD/siVEGF complexes exhibited significant distribution at tumor sites and caused obvious inhibition of tumor growth and tumor-associated angiogenesis repression induced by the drug combination of CD and siVEGF. Finally, a WST-1 assay indicated that SWNT-PEI-CD possessed low cytotoxicity, and a hemolysis test showed good biocompatibility of SWNT-PEI-CD. Hematological and histological analyses confirmed that SWNT-PEI-CD/siVEGF complexes did not cause any obvious toxic effects to blood and major organs. These findings suggested that the SWNT-PEI-CD/siVEGF co-delivery system with tumor-targeting specificity, improved endosomal escaping properties, and collaboration of angiogenesis inhibition could be a prospective method for efficient tumor antiangiogenic therapy.

Artemisinin (ARS) and its derivatives, which are clinically used antimalarial agents, have shown antitumor activities. Their therapeutic potencies, however, are limited by their low solubility and poor bioavailability. Here, through a pharmacophore hybridization strategy, we synthesized ARS-drug conjugates, in which the marketed chemotherapeutic agents chlorambucil, melphalan, flutamide, aminoglutethimide, and doxifluridine, were separately bonded to Dihydroartemisinin (DHA) through various linkages. Of these, the artemisinin-melphalan conjugate, ARS4, exhibited most toxicity to human ovarian cancer cells but had low cytotoxicity to normal cells. ARS4 inhibited the growth and proliferation of ovarian cancer cells and resulted in S-phase arrest, apoptosis, and inhibition of migration; these effects were stronger than those of its parent drugs, DHA and melphalan. Furthermore, ARS4 modulated the expression of proteins involved in cell cycle progression, apoptosis, and the epithelial–mesenchymal transition (EMT). Moreover, in mice, ARS4 inhibited growth and intraperitoneal dissemination and metastasis of ovarian cancer cells without observable toxic effects. Our results provide a basis for development of the compound as a chemotherapeutic agent.Research in contextArtemisinin compounds have recently received attention as anticancer agents because of their clinical safety profiles and broad efficacy. However, their therapeutic potencies are limited by low solubility and poor bioavailability. Here, we report that ARS4, an artemisinin-melphalan conjugate, possesses marked in-vitro and in-vivo antitumor activity against ovarian cancer, the effects of which are stronger than those for its parent drugs, Dihydroartemisinin and melphalan. In mice, ARS4 inhibits localized growth of ovarian cancer cells and intraperitoneal dissemination and metastasis without appreciable host toxicity. Thus, for patients with ovarian cancer, ARS4 is a promising chemotherapeutic agent.

Unlike other common modes of cell death, such as apoptosis, necrosis, and autophagy, ferroptosis is triggered by iron-dependent accumulation of lipid peroxides (LPO), resulting in an oxidation-reduction imbalance in cells. [2] It has been reported that ferroptosis is closely associated with the occurrence and progression of malignant diseases and particularly plays a critical role in regulating the sensitivity of cancer cells to anticancer treatments, suggesting its importance in cancer treatment. [3] Recently, significant efforts have been devoted to revealing the anticancer role of ferroptosis and various ferroptosis-based cancer therapies have been proposed to inhibit tumor growth. [4] However, current ferroptosis strategy has failed to fulfill therapeutic promise due to the complex, heterogenous, and dynamic tumor microenvironment. [5] Particularly, a very high dose of Fe ions is needed to achieve oxidative stress to initiate the ferroptosis process, which always leads to unsatisfied therapeutic effects on alleviating the disease progression. [4,6] To enhance the therapeutic efficacy, some ferroptosis-inducing agents have been developed, [7] such as ferroptosis activators including erastin, [8] sulfasalazine, [9] and buthionine sulfoximine, [10] as well as glutathione peroxidase 4 (GPX4) inhibitors including Ras selective lethal 3 (RSL3). [11] Ferroptosis is a type of nonapoptotic cell death and is gradually emerging as an important anticancer treatment. However, its therapeutic efficacy is impaired by low intracellular levels of reactive oxygen species (ROS) and long-chain polyunsaturated fatty acids, significantly limiting its therapeutic potential. Herein, a multimodal strategy to improve ferroptosis is presented, in which a state-of-art engineered erythrocyte, termed as sonodynamic amplified ferroptosis erythrocyte (SAFE), is developed for simultaneously activating ferroptosis and oxygen-riched sonodynamic therapy (SDT). SAFE is composed of internalizing RGD peptide and red blood cell membrane hybrid camouflaged nanocomplex of hemoglobin, perfluorocarbon, ferroptosis activator (dihomo-γ-linolenic acid, DGLA), and sonosensitizer verteporfin. It is identified that SAFE, under ultrasound stimulation, can not only substantially supply oxygen to overcome tumor hypoxia associated therapeutic resistance, but effectively activate ferroptosis through the coeffect of SDT triggered ROS production and DGLA mediated lipid peroxidation. In vivo studies reveal that SAFE selectively accumulates in tumor tissues and induces desirable anticancer effects under mild ultrasound stimulation. Importantly, SAFE can effectively inhibit tumor growth with minimal invasiveness, resulting in a prolonged survival period of mice. Therefore, a multimodal ferroptosis therapy driven by oxygen-riched sonodynamic peroxidation of lipids, significantly advancing synergistic cancer treatment, is presented.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/smll.202106568.