RNA Hydrogel Combined with MnO2 Nanoparticles as a Nano-Vaccine to Treat Triple Negative Breast Cancer

Hypoxia is not only the reason of tumor metastasis but also enhances the spread of cancer cells from the original tumor site, which results in cancer recurrence. Herein, we developed a self-assembled RNA hydrogel that efficiently delivered synergistic DNA CpG and short hairpin RNA (shRNA) adjuvants, as well as MnO2 loaded-photodynamic agent chlorine e6 (MnO2@Ce6), and a chemotherapy drug doxorubicin (DOX) into MDA-MB-231cells. The RNA hydrogel consists of one tumour suppressor miRNA (miRNA-205) and one anti-metastatic miRNA (miRNA-182), both of which showed an outstanding effect in synergistically abrogating tumours. The hydrogel would be dissociated by endogenous Dicer enzyme to release loaded therapeutic molecules, and in the meantime induce decomposition of tumor endogenous H2O2 to relieve tumor hypoxia. As a result, a remarkable synergistic therapeutic effect is achieved through the combined chemo-photodynamic therapy, which simultaneously triggers a series of anti-tumor immune responses. Besides, the hydrogel as the carrier which modified aptamer to targeted MDA-MB-231 has the advantages of good biocompatibility and low cytotoxicity. This strategy could be implemented to design any other microRNA (miRNA) as the carrier, combined with other treatment methods to treat human cancer, thereby overcoming the limitations of current cancer therapies.

Biogenic Synthesis of MnO2 Nanoparticles With Leaf Extract of Viola betonicifolia for Enhanced Antioxidant, Antimicrobial, Cytotoxic, and Biocompatible Applications

In this study, we propose to synthesize NPs using plant extract containing active biomedical components, with the goal of obtaining NPs that inherit the biomedical activities of the plant. Herein, we report the synthesis of manganese dioxide nanoparticles (VBLE-MnO2 NPs) using the leaves extract of Viola betonicifolia, in which the biological active plant’s secondary metabolites function as both reducing and capping agents. The synthesized NPs were successfully characterized with different spectroscopic techniques. The antibacterial, antifungal, and biofilm inhibition properties of the synthesized VBLE-MnO2 NPs were further explored against a variety of bacteria (Gram-positive and Gram-negative) and mycological species. Additionally, their antioxidant ability against linoleic acid peroxidation inhibition, cytobiocompatibility with hMSC cells, and cytotoxicity against MCF-7 cells were investigated compared to leaves extract and chemically synthesized manganese dioxide NPs (CH-MnO2 NPs). The results were demonstrated that the synthesized VBLE-MnO2 NPs presented excellent antibacterial, antifungal, and biofilm inhibition performance against all the tested microbial species compared to plant leaves extract and CH-MnO2 NPs. Moreover, they also exhibited significant antioxidant potential, which was comparable to the external standard (ascorbic acid); however, it was higher than plant leaves extract and CH-MnO2 NPs. Furthermore, the synthesized CH-MnO2 NPs displayed good cytobiocompatibility with hMSC cells compared to CH-MnO2 NPs. The enhanced antioxidant, antibacterial, antifungal, and biofilm inhibition efficacy as compared to CH-MnO2 NPs might be attributed to the synergistic effect of the VBLE-MnO2 NPs’ physical properties and the adsorbed biologically active phytomolecules from the leaves extract of V. betonicifolia on their surface. Thus, our study establishes a novel ecologically acceptable route for nanomaterials’ fabrication with increased and/or extra medicinal functions derived from their herbal origins.