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LaMnO3 exhibits an excellent degradation ability of RhB under highly acidic conditions without adding additional oxidants or light irradiation.

Abstract A series of CuS/Bi2WO6 composites were synthesized by solvothermal synthesis, which showed enhanced photocatalytic activity. The as-prepared samples were characterized by X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, photoluminescence ultraviolet–visible absorption spectroscopy, transient photocurrent and EIS. The results showed that as-prepared CuS/Bi2WO6 has flower-like nano microspheres self-assembled by nanoplates and CuS nanorods are uniformly dispersed on its surface. The CuS/Bi2WO6 forms heterojunctions between CuS and Bi2WO6 and shows a wide light response range and a strong light response intensity. The CuS/Bi2WO6 exhibits a better Rhodamine B (RhB) degradation effect than pure Bi2WO6 and CuS, and it can degrade 90% RhB in 50 min and achieve complete degradation in 70 min under Xe lamp irradiation. The CuS/Bi2WO6 has photocatalytic activity in a low pH environment and good stability. The formation of a heterojunction between CuS and Bi2WO6 can effectively separate photo-generated electrons and holes, greatly improving the photocatalytic activity. In the CuS/Bi2WO6-RhB reaction system, O2− is the main active species, and it can rapidly remove the ethyl group from the amino group linked to benzene rings to achieve the N-de-ethylation reaction in the process of RhB degradation. The N-de-ethylated products are simultaneously degraded to small organic molecules and even mineralized into CO2 and H2O.

Objective Gastric cancer is one of the most lethal malignancies in the world. However, the current research on the diagnosis and treatment of nano-ultrasound contrast agents in the field of tumor is mostly focused on breast cancer, ovarian cancer, prostate cancer, liver cancer, etc. Due to the interference of gas in the stomach, there is no report on the treatment of gastric cancer. Herpes simplex virus thymidine kinase/ganciclovir (HSV-TK/GCV) therapy system is the most mature tumor suicide gene in cancer treatment. At the same time, in order to improve its safety and efficiency, we designed a gastric tumor targeted ultrasound-triggered phase-transition nano ultrasound contrast agent PFH/AGM-CBA/HSV-TK/Liposome (PAHL)-Affibody complex. Methods In our study, guanidinylated SS-PAAs polymer poly(agmatine/N, N′-cystamine-bis-acrylamide) (AGM-CBA) was used as a nuclear localization vector of suicide gene to form a polyplex, perfluorohexane (PFH) was used as ultrasound contrast agent, liposomes were used to encapsulate perfluorohexane droplets and the polyplexes of AGM-CBA/HSV-TK, and affibody molecules were conjugated to the prepared PAHL in order to obtain a specific targeting affinity to human epidermal growth factor receptor type 2 (ErbB2) at gastric cancer cells. With the aid of ultrasound targeted microbubble destruction technology and the nuclear localization effect of AGM-CBA vector, the transfection efficiency of the suicide gene in gastric cancer cells was significantly increased, leading to significant apoptosis of gastric cancer cells. Results It was shown that PAHL-Affibody complex was nearly spherical with an average diameter of 560 ± 28.9 nm, having higher and specific affinity to ErbB2 (+) gastric cells. In vitro experiments further confirmed that PAHL could target gastric cancer cells expressing ErbB2. In a contrast-enhanced ultrasound scanning study, the prepared ultrasound-triggered phase-change nano-ultrasound contrast agent, PAHL, showed improved ultrasound enhancement effects. With the application of the low-frequency ultrasound, the gene transfection efficiency of PAHL was significantly improved, thereby inducing significant apoptosis in gastric cancer cells. Conclusion This study constructs PFH/AGM-CBA/HSV-TK/Liposome-Affibody nano ultrasound contrast agent, which provides new ideas for the treatment strategy of ErbB2-positive gastric cancer and provides some preliminary experimental basis for its inhibitory effect.