Brazil has the second highest number of deaths due to COVID-19. Obesity has been associated with an important role in disease development and a worse prognosis. We aimed to explore epidemiological data from Brazil, discussing the potential relationships between obesity and COVID-19 severity in this country. We used a public database made available by the Ministry of Health of Brazil (182700 patients diagnosed with COVID-19). Descriptive statistics were used to characterize our database. Continuous data were expressed as median and analyzed by the nonparametric tests Mann–Whitney or one-sample Wilcoxon. The frequencies of categorical variables have been analyzed by chi-square tests of independence or goodness-of-fit. Among the number of deaths, 74% of patients were 60 years of age or older. Patients with obesity who died of COVID-19 were younger (59 years (IQR = 23)) than those without obesity (71 years (IQR = 20), , and η² = 0.0424). Women with obesity who died of COVID-19 were older than men (55 years (IQR = 25) vs. 50 (IQR = 22), , and η² = 0.0263). Furthermore, obesity increases the chances of needing intensive care unit (OR: 1.783, CI: 95%, and ), needing ventilatory support (OR: 1.537, CI: 95%, and and OR: 2.302, CI: 95%, and , for noninvasive and invasive, respectively), and death (OR: 1.411, CI: 95%, and ) of patients hospitalized with COVID-19. Our analysis supports obesity as a significant risk factor for the development of more severe forms of COVID-19. The present study can direct a more effective prevention campaign and appropriate management of subjects with obesity.

The current article reports the investigation of three new Ni(II) complexes with ONS-donor dithiocarbazate ligands: [Ni(L¹)PPh₃] (1), [Ni(L²)PPh₃] (2), and [Ni(L²)Py] (3). Single-crystal X-ray analyses revealed mononuclear complexes with a distorted square planar geometry and the metal centers coordinated with a doubly deprotonated dithiocarbazate ligand and coligand pyridine or triphenylphosphine. The non-covalent interactions were investigated by the Hirshfeld surface and the results revealed that the strongest interactions were π⋅⋅⋅π stacking interactions and non-classical hydrogen bonds C–H···H and C–H···N. Physicochemical and spectroscopic methods indicate the same structures in the solid state and solution. The toxicity effects of the free ligands and Ni(II) complexes were tested on the human breast cancer cell line MCF-7 and non-malignant breast epithelial cell line MCF-10A. The half-maximal inhibitory concentration (IC₅₀) values, indicating that the compounds were potent in inhibiting cell growth, were obtained for both cell lines at three distinct time points. While inhibitory effects were evident in both malignant and non-malignant cells, all three complexes demonstrated lower IC₅₀ values for malignant breast cell lines than their non-malignant counterparts, suggesting a stronger impact on cancerous cell lines. Furthermore, molecular docking studies were performed showing the complex (2) as a promising candidate for further therapeutic exploration.

Breast cancer is the most common type of cancer that affects and kills women annually in the world. It impacts more than two million women and is responsible for the death of approximately 25% of them. Almost 70% of breast cancer diagnoses are positive for hormone receptor and have a good prognosis. However, resistance to drugs used in hormone therapy, such as tamoxifen, is usual and about 40% of recurrences do not respond to it. In some cases, the overexpression of the HOXB7 gene is related to this mechanism and its silencing can reverse the response to tamoxifen. Here, we used copolymer-coated calcium phosphate nanoparticles to deliver HOXB7 siRNA and restore the sensitization of MCF7 cells to tamoxifen. Nanoparticle synthesis and characterization were performed, and cell viability and gene expression were evaluated. Hybrid nanoparticle presented a Z-average diameter of 83 nm and polydispersity index (PdI) of 0.07, while showing good entrapment of siRNA molecules. We also observed a decrease in HOXB7 gene expression (~65%) promoted by the siRNA molecule delivered by the nanoparticles. The gene silencing has good correlation to the cell viability assay: a reduction in breast cancer viability was observed in 48 (31%) and 72 (38%) hours. As for the co-treatment with tamoxifen, cell viability started dropping after 15 h, which did not occur in the treatment only with Tamoxifen at the same concentration. This result indicates that the biological effect was possibly related to RNAi effect and suggests that HOXB7 may be promoting cell sensitization to tamoxifen without reducing cell viability. Overall, these results suggest that the nanostructured system was effective in promoting gene silencing and that the co-therapy can be a promising tool for the treatment of hormone receptor-positive breast cancers.