In this paper, polycrystalline molybdenum disulfide (MoS 2 ) nanoflowers were prepared by mixing ammonium molybdate tetrahydrate [(NH 4 ) 6 Mo 7 O 24 ·4H 2 O] and potassium thiocyanate (KSCN) at 300 °C for 2 h via molten salt sintering method. Under scanning electron microscope (SEM) and high-resolution transmission electron microscope (HRTEM), MoS 2 showed popcorn-like shape, which surface distribution defects were easy to be further modified. MoS 2 as a nano-enzyme was used to inhibit the proliferation of mouse breast cancer cells (4 T1), which had 69.8 % inhibitory effect on 4 T1 cell proliferation. Electron spin resonance (ESR) analysis showed that MoS 2 could produce a large number of stable hydroxyl radicals (–OH). The disulfide bond in MoS 2 was highly sensitive to reactive oxygen species (ROS). High ROS level leads to the death of cancer cells under oxidative stress and inhibits the proliferation of 4 T1. This work demonstrates that MoS 2 is a potential anticancer drug or carrier for cancer treatment.
Xinyun Li,Dandan Xing,Yangjing Bai,Yangrui Du,Shiying Lang,Kaijun Li,Jun Xiang,Gongyan Liu,Shan Liu
Clinically, tumor removal surgery leaves irregularly shaped wounds that are susceptible to bacterial infection and further lead to excessive inflammation. Injectable hydrogel dressings with antimicrobial and anti-inflammatory properties have been recognized as an effective strategy to care for postoperative tumor wounds and prevent recurrence in recent years. In this work, we constructed a hydrogel network by ionic bonding interactions between quaternized chitosan (QCS) and EGCG-Zn complexes which were coordinated by epigallocatechin gallate (EGCG) and zinc ions (Zn2+). Because of the synergistic effect of QCS and EGCG-Zn, the hydrogel exhibited outstanding antimicrobial capacity (>99.9% inhibition), which could prevent infections caused by Escherichia coli and Staphylococcus aureus. In addition, the hydrogel was able to inhibit the growth of mice breast cancer cells (56.81% survival rate within 72 h) and reduce inflammation, which was attributed to the sustained release of EGCG. The results showed that the hydrogel was effective in inhibiting tumor recurrence and accelerating wound closure when applied to the postoperative tumor wounds. This study provided a simple and reliable strategy for postoperative tumor wound care using antimicrobial and anti-inflammatory injectable dressings, confirming their great potential in the field of postoperative wound dressings.
The clinical efficacy of immune checkpoint blockade (ICB) therapy is significantly compromised in the metabolically disordered tumor microenvironment (TME), posing a formidable challenge that cannot be ignored in current antitumor strategies. In this study, TME-responsive nanoparticles (HMP1G NPs) loaded with 1-methyltryptophan (1-MT; an indoleamine 2,3-dioxygenase 1 [IDO1] inhibitor,) and S-nitrosoglutathione (GSNO; a nitric oxide donor) is developed to enhance the therapeutic efficacy of 1-MT-mediated ICB. The HMP1G NPs responded to H + and glutathione in the TME, releasing Mn 2+ , GSNO, and 1-MT. The released Mn 2+ catalyzed the production of abundant reactive oxygen species and nitric oxide from hydrogen peroxide and GSNO, and the generated nitric oxide, synergistically with 1-MT, inhibited the accumulation of kynurenine mediated by IDO1 in the tumor. Mechanistically, HMP1G NPs downregulated tumor cell-derived IDO1 via the aryl hydrocarbon receptor/signal transducer and activator of transcription 3/interleukin signaling axis to improve kynurenine/tryptophan metabolism and immunosuppression. In a murine breast cancer model, treatment with HMP1G NPs elicited effective antitumor immunity and enhanced survival outcomes. This study highlights a novel nano-platform that simultaneously improves metabolism and enhances ICB efficacy to achieve a new and efficient antitumor strategy.
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