An Acid-Responsive Iron-Based Nanocomposite for OSCC Treatment

Oral squamous cell carcinoma (OSCC) is the most common type of oral cancer, characterized by invasiveness, local lymph node metastasis, and poor prognosis. Traditional treatment and medications have limitations, making the specific inhibition of OSCC growth, invasion, and metastasis a challenge. The tumor microenvironment exhibits mildly acidity and high concentrations of H2O2, and its exploitation for cancer treatment has been widely researched across various cancers, but research in the oral cancer field is relatively limited. In this study, by loading ultra-small Prussian blue nanoparticles (USPBNPs) into mesoporous calcium-silicate nanoparticles (MCSNs), we developed an acid-responsive iron-based nanocomposite, USPBNPs@MCSNs (UPM), for the OSCC treatment. UPM demonstrated excellent dual enzyme activities, generating toxic ·OH in a mildly acidic environment, effectively killing OSCC cells and producing O2 in a neutral environment to alleviate tissue hypoxia. The results showed that UPM could effectively inhibit the proliferation, migration, and invasion of OSCC cells, as well as the growth of mice solid tumors, without obvious systemic toxicity. The mechanisms may involve UPM inducing ferroptosis of OSCC cells by downregulating the xCT/GPX4/glutathione (GSH) axis, characterized by intracellular iron accumulation, reactive oxygen species accumulation, GSH depletion, lipid peroxidation, and abnormal changes in mitochondrial morphology. Therefore, this study provides empirical support for ferroptosis as an emerging therapeutic target for OSCC and offers a valuable insight for future OSCC treatment.

Effects of different electrostatic field intensities assisted controlled freezing point storage on water holding capacity of fresh meat during the early postmortem period

In this study, the effect of different intensity electrostatic fields on the water holding capacity (WHC) of fresh meat during the early postmortem period in controlled freezing point storage (CFPS) were investigated. Significantly lower cooking loss were found in low voltage electrostatic field (LVEF) and high voltage electrostatic field (HVEF) compared to the control group (CK) (p < 0.05). The myofibril fragmentation index and microstructure results suggested that the sample under HVEF treatment remained relatively intact. It has been revealed that the changes in actomyosin properties under electrostatic field treatment groups were due to the combination and dissociation of actomyosin binding into myofilament concentration, which consequently affects the muscle WHC. The study further demonstrated that the electrostatic field, especially HVEF, might increase the WHC of fresh meat by affecting the distribution of water molecules and physiochemical properties of actomyosin during the early postmortem period.

High-Intensity Ultraviolet-C Irradiation Efficiently Inactivates SARS-CoV-2 Under Typical Cold Chain Temperature

SARS-CoV-2 contaminated items in the cold chain becomes a threat to public health, therefore the effective and safe sterilization method fit for the low temperature is needed. Ultraviolet is an effective sterilization method while its effect on SARS-CoV-2 under low-temperature environment is unclear. In this research, the sterilization effect of high-intensity ultraviolet-C (HIUVC) irradiation against SARS-CoV-2 and Staphylococcus aureus on different carriers at 4 °C and - 20 °C was investigated. The results showed that dose of 15.3 mJ/cm² achieved more than 3 log reduction of SARS-CoV-2 on gauze at 4 °C and - 20 °C. The vulnerability of coronavirus to HIUVC under - 20 °C was not significantly different than those under 4 °C. Four models including Weibull, biphasic, log-linear tail and log linear were used to fit the survival curves of SARS-CoV-2 and Staphylococcus aureus. The biphasic model fitted best with R² ranging from 0.9325 to 0.9878. Moreover, the HIUVC sterilization correlation between SARS-CoV-2 and Staphylococcus aureus was established. This paper provides data support for the employment of HIUVC under low-temperature environment. Also, it provides a method of using Staphylococcus aureus as a marker to evaluate the sterilization effect of cold chain sterilization equipment.

Alteration of endothelial nitric oxide synthase expression in acute pulmonary embolism: a study from bench to bioinformatics

OBJECTIVE

This study sought to explore endothelial nitric oxide synthase (eNOS) expression in acute pulmonary thromboembolism (APE).

MATERIALS AND METHODS

eNOS expression in lung tissue and bone marrow-derived endothelial progenitor cells (BM-EPCs) from APE mouse models was assessed by immunohistochemistry and real-time PCR. A gene expression profile meta-analysis was performed on human venous thromboembolism (VTE) whole blood samples recorded in the Gene Expression Omnibus (GEO) repository. Significantly expressed genes were determined from the microarray data by unsupervised clustering and supervised classification. Selected sample data with significantly expressed genes were further analyzed by principal component analysis (PCA), followed by Bayesian probit regression. Key discriminate genes were further grouped and annotated using functional annotations and gene enrichments using the online Database for Annotation, Visualization and Integrated Discovery (DAVID) software (v. 6.7).

RESULTS

While eNOS expression was significantly higher, serum nitric oxide levels were significantly lower in APE mice (20.42 ± 2.15 μM) compared to controls (53.50 ± 5.69 μM, p<0.001). eNOS mRNA and protein levels were significantly upregulated in BM-EPCs from APE mice. GEO repository data reported 3,397 upregulated and 4,173 downregulated genes (including eNOS) in VTE patients. In this regression analysis, the significant principal component PC1 and PC2 (p<0.05) were useful in distinguishing the VTE classification. The coefficient value of eNOS was -0.47707 in PC1 and -0.08429 in PC2, which did have some proportions on these significantly discriminated components but did not contribute significantly to the VTE classification. Functional enrichment in terms of acetylation and phosphoproteins were high.

CONCLUSIONS

Our findings, therefore, suggest that expression of eNOS is significantly altered in APE and may be a potential peripheral blood biomarker. Modulation of eNOS expression may be used for APE treatment.