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Objective: This study aims to investigate the effects of pectin-degrading bacteria on the microbial community and physicochemical properties during the fermentation process of cigar tobacco, evaluating its potential in reducing green bitterness and enhancing aroma. Methods: By isolating and screening pectin-degrading bacteria, high-throughput sequencing and physicochemical analysis were employed to compare the microbial flora and physicochemical component differences in different treatment groups of cigar tobacco. Furthermore, correlation analysis was performed to examine the relationships between these variables. Results: The results showed that the strains YX-2 and DM-3, isolated from the cigar tobacco variety " Yunxue No. 1 ," exhibited strong pectin-degrading abilities. Phylogenetic analysis revealed that strain YX-2 is highly homologous to Bacillus flexus , while strain DM-3 is highly homologous to Bacillus siamensis. After fermentation, the addition of strains YX-2 and DM-3 significantly reduced the pectin content in the tobacco leaves, increased the total sugar and reducing sugar content, reduced green bitterness, and markedly enhanced the total aroma components. Notably, DM-3 exhibited outstanding performance in the production of Maillard reaction products. Microbial community analysis showed that the addition of pectin-degrading bacteria significantly increased the diversity of both bacteria and fungi, especially in the TDM3 group, where the relative abundance of Pseudomonas was notably elevated. Correlation analysis revealed that Pseudomonas had a significant positive correlation with both reducing sugar and total sugar, and a significant negative correlation with pectin, indicating its important role in sugar metabolism and pectin degradation. Additionally, fungal genera such as Cercospora were significantly negatively correlated with total sugar and total nitrogen, while Eurotium was closely associated with pectin degradation and reducing sugar accumulation. Conclusion: This study found that the addition of Pectin-degrading bacteria YX-2 and DM-3 significantly optimized the microbial community structure during the cigar tobacco fermentation process and improved the physicochemical properties of the tobacco leaves, with notable effects in reducing green bitterness and enhancing aroma. [ABSTRACT FROM AUTHOR]

Quantum dots (QDs) represent a class of nanoscale wide bandgap semiconductors, and are primarily composed of metals, lipids, or polymers. Their unique electronic and optical properties, which stem from their wide bandgap characteristics, offer significant advantages for early cancer detection and treatment. Metal QDs have already demonstrated therapeutic potential in early tumor imaging and therapy. However, biological toxicity has led to the development of various non-functionalized QDs, such as carbon QDs (CQDs), graphene QDs (GQDs), black phosphorus QDs (BPQDs) and perovskite quantum dots (PQDs). To meet the diverse needs of clinical cancer treatment, functionalized QDs with an array of modifications (lipid, protein, organic, and inorganic) have been further developed. These advancements combine the unique material properties of QDs with the targeted capabilities of biological therapy to effectively kill tumors through photodynamic therapy, chemotherapy, immunotherapy, and other means. In addition to tumor-specific therapy, the fluorescence quantum yield of QDs has gradually increased with technological progress, enabling their significant application in both in vivo and in vitro imaging. This review delves into the role of QDs in the development and improvement of clinical cancer treatments, emphasizing their wide bandgap semiconductor properties. [ABSTRACT FROM AUTHOR]

Semiconductor nanomaterials have emerged as a significant factor in the advancement of tumor immunotherapy. This review discusses the potential of transition metal oxide (TMO) nanomaterials in the realm of anti-tumor immune modulation. These binary inorganic semiconductor compounds possess high electron mobility, extended ductility, and strong stability. Apart from being primary thermistor materials, they also serve as potent agents in enhancing the anti-tumor immunity cycle. The diverse metal oxidation states of TMOs result in a range of electronic properties, from metallicity to wide-bandgap insulating behavior. Notably, titanium oxide, manganese oxide, iron oxide, zinc oxide, and copper oxide have garnered interest due to their presence in tumor tissues and potential therapeutic implications. These nanoparticles (NPs) kickstart the tumor immunity cycle by inducing immunogenic cell death (ICD), prompting the release of ICD and tumor-associated antigens (TAAs) and working in conjunction with various therapies to trigger dendritic cell (DC) maturation, T cell response, and infiltration. Furthermore, they can alter the tumor microenvironment (TME) by reprogramming immunosuppressive tumor-associated macrophages into an inflammatory state, thereby impeding tumor growth. This review aims to bring attention to the research community regarding the diversity and significance of TMOs in the tumor immunity cycle, while also underscoring the potential and challenges associated with using TMOs in tumor immunotherapy. [ABSTRACT FROM AUTHOR]

Objective: To explore the effect of Dickkopf-1 (DKK1) expression on CD4+ T cell polarization in malignant tumors and its potential value as a target for cancer immunotherapy. Methods: Bioinformatics algorithm was used to analyze the expression of DKK1 in multiple types of tumor tissues and adjacent tissues, and the correlation between the expression of DKK1 and the prognosis of cancer patients and immune infiltration of tumor microenvironment. The effect of DKK1 protein on the phenotype of CD4+ T cells was analyzed by flow cytometry in vitro. A melanoma B16F10 cell mouse subcutaneous transplantation tumor model was established to observe the effects of blocking DKK1 on the growth of mouse transplantation tumor and immune cell infiltration and phenotype in transplantation tumor tissues. Results: The mRNA expression levels of DKK1 in many kinds of tumor tissues were significantly higher than those in adjacent tissues. High expression of DKK1 was related to the poor prognosis of most tumor patients. In most types of tumors DKK1 played important negative regulatory role in CD4+ T cell anti-tumor immune response (P<0.05 or P<0.01). The results of flow cytometry in vitro showed that DKK1 protein stimulation significantly decreased the expression levels of T-bet, IFN-γ and CD107a in CD4+ T cells (all P<0.01). In the mouse subcutaneous melanoma model, it was found that blocking DKK1 could significantly inhibit the growth of transplanted tumors (P<0.01) and effectively improve the anti-tumor immune responses including the proportion of Th1 cells (T-bet+CD4+) increasing significantly (P<0.001), the proportion of effector CD8+ T cells (CD44+CD62L-) increasing significantly (P<0.01), and the proportion of Th2 cells (GATA3+CD4+) and Treg cells decreasing significantly (both P<0.01). Conclusion: Blocking DKK1 can effectively promote the phenotypic polarization of CD4+ T cells to Th1. DKK1 has potential value as a target for tumor immunotherapy. [ABSTRACT FROM AUTHOR]

Effective antitumor agents with concurrent osteogenic properties are essential for comprehensive osteosarcoma (OS) treatment. However, the current clinical therapeutic strategies of OS fail to completely eradicate tumors while simultaneously encouraging bone formation. To address this issue, a switchable strategy for dynamic OS ablation and static bone regeneration is developed by integrating piezoelectric BaTiO3 (BTO) with atomic‐thin Ti3C2 (TC) through a Schottky heterojunction, resulting in the formation of TC@BTO. Under sequential ultrasound and near‐infrared irradiation, the optimized carrier transport of TC@BTO, based on Schottky heterojunction, exhibits excellent characteristics of photothermal conversion and reactive oxygen species generation. This results in ferroptosis of tumor cells and eventual elimination of OS. Moreover, in the static state, the interfacial Schottky heterojunction facilitates the carriers' directed transfer from the semiconductor to the metal. The Schottky heterojunction‐enhanced static electrical stimulation enhances the osteogenic differentiation of bone marrow‐derived mesenchymal stem cells and repair of bone defects. Furthermore, RNA‐sequencing analysis reveals that static TC@BTO promotes bone regeneration by activating Wnt signaling pathway, and remarkably, pharmacological inhibition of Wnt signaling suppresses the TC@BTO‐induced osteogenesis. Overall, this work broadens the biomedical potential of Schottky heterojunction‐based therapies and provides a comprehensive strategy for overall OS ablation and bone regeneration. [ABSTRACT FROM AUTHOR]

Cold tumor is one of the most refractory tumors due to its low immunogenicity and absence of T cell infiltration. The immunotherapeutic effect of near‐infrared (NIR) responsive nanomaterials on tumors is far from satisfactory. Herein, ultrasmall γ‐MnO2 nanodots are anchored on the intrinsic metallic Ti3C2(OH)2, modified with bovine serum albumin, to realize a Schottky heterojunction (labeled as TC‐MnO2@BSA), which can be utilized to reshape the cold tumor microenvironment (TME) through in situ vaccine‐like antitumor effect. The Schottky heterojunction endows TC‐MnO2@BSA with improved photothermal conversion and reactive oxygen species (ROS) generation. Excess ROS and heat lead to tumor immunogenic death (ICD) and abundant damaged double‐strain DNA releasing into TME, coordinated with TC‐MnO2@BSA‐derived Mn2+, magnifying the cGAS‐STING signaling pathway, eventually promoting antigen presentation of dendritic cells and infiltration of T cells. Such a NIR‐activated nanovaccine can achieve complete ablation of tumors while robust activating systemic antitumor immune response. Furthermore, it inhibits the growth of abscopal tumors through dramatically "heating" their cold TME. This work introduces a universal strategy to magnify the photothermal and immune adjuvant effect through the gain of Schottky heterostructure, as a novel paradigm to construct the multifunctional in situ nanovaccine. [ABSTRACT FROM AUTHOR]