Collagen matrices are preserved following decellularization of a bovine bone scaffold.

The decellularization of bovine bone has emerged as a strategy for the repair, replacement, and regeneration of bone defects. To evaluate the effects of a new protocol of bone decellularization and its impact on the structure and collagen scaffold. Cancellous bone from bovine femur was dissected in fragments and decellularized based on protocol of multiple steps. The residual protein levels, histological, morphometric, and scanning electronic microscopy analyses were carried out to evaluate the effects of decellularization and the impact on the structure and collagen scaffold. A cytotoxicity assay was performed. Residual protein analysis showed an important removal of bone marrow components and cell debris from the bone. Sections revealed that collagen fibers presented integrity and absence of cells in the decellularized bone. Sirius Red-stained sections of collagen fiber collagen matrix were maintained after decellularization. Scanning electron microscopy revealed that the main bone structure, despite being irregular, was maintained in both groups, with no significant visual differences between the surface characteristics according to the groups. Decellularized bovine bone demonstrated a degree of toxicity of 3, indicating moderate reactivity. The present data demonstrate that the main bone structure was maintained. Additionally, the chemical and physical treatments were able to remove cellular debris, and extracellular matrix architecture and collagen were preserved. However, the tissue showed moderate toxicity.

COVID-19 Outcome Relates With Circulating BDNF, According to Patient Adiposity and Age.

Background and Aims: We evaluated adipose tissue-derived hormones, body composition, serum metabolic profile, levels of brain-derived neurotrophic factor (BDNF), and the association of these parameters with the clinical outcome in patients with COVID-19. We sought to examine whether obesity, sex, and age influence the adipose tissue endocrine response to the disease. Methods: This prospective study investigated 145 hospitalized patients with COVID-19. Patients were categorized based on their body mass index (BMI), sex and age, and were also classified regarding their outcome after hospitalization as: (a) Non-ICU: patients hospitalized who did not receive intensive care; (b) ICU-survivor: patients admitted to the intensive care unit and discharged; (c) ICU-death: patients who died. Blood samples were collected by the hospital staff between the first and third day of hospitalization. Serum leptin, adiponectin and BDNF concentrations, triglycerides, total cholesterol and cholesterol fractions were performed following the manufacturer's guidelines. Results: We demonstrate that BDNF levels predict intensive care (IC) need (p < 0.01). This association was found to be stronger in patients >60y (p = 0.026). Neither leptin nor adiponectin concentration was associated with IC requirement or with patient's outcome, while the BDNF/adiponectin ratio was closely associated with worsened outcomes (p < 0.01). BDNF concentration was similar between sexes, however tended to be lower in male patients (p = 0.023). In older patients, BDNF concentration was lower than that of younger patients (p = 0.020). These age and sex-specific differences should be considered when employing these potential markers for prognosis assessment. While appetite and body composition regulating hormones secreted by the white adipose tissue are not reliable predictors of disease severity, the ratio BDNF/adiponectin was indicative of patient status. Conclusion: Thus, we propose that serum BDNF content and BDNF/adiponectin ratio may serve as tools predicting worsened prognosis in COVID-19, especially for male patients.