Coagulation System Activation for Targeting of COVID-19: Insights into Anticoagulants, Vaccine-Loaded Nanoparticles, and Hypercoagulability in COVID-19 Vaccines

Alveolar Hyperoxia and Exacerbation of Lung Injury in Critically Ill SARS-CoV-2 Pneumonia

Acute hypoxic respiratory failure (AHRF) is a prominent feature of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) critical illness. The severity of gas exchange impairment correlates with worse prognosis, and AHRF requiring mechanical ventilation is associated with substantial mortality. Persistent impaired gas exchange leading to hypoxemia often warrants the prolonged administration of a high fraction of inspired oxygen (FiO2). In SARS-CoV-2 AHRF, systemic vasculopathy with lung microthrombosis and microangiopathy further exacerbates poor gas exchange due to alveolar inflammation and oedema. Capillary congestion with microthrombosis is a common autopsy finding in the lungs of patients who die with coronavirus disease 2019 (COVID-19)-associated acute respiratory distress syndrome. The need for a high FiO2 to normalise arterial hypoxemia and tissue hypoxia can result in alveolar hyperoxia. This in turn can lead to local alveolar oxidative stress with associated inflammation, alveolar epithelial cell apoptosis, surfactant dysfunction, pulmonary vascular abnormalities, resorption atelectasis, and impairment of innate immunity predisposing to secondary bacterial infections. While oxygen is a life-saving treatment, alveolar hyperoxia may exacerbate pre-existing lung injury. In this review, we provide a summary of oxygen toxicity mechanisms, evaluating the consequences of alveolar hyperoxia in COVID-19 and propose established and potential exploratory treatment pathways to minimise alveolar hyperoxia.

Anticoagulant effect of Feijoa sellowiana extracts generated by different biotechnological techniques

Blood clotting has become one of the most dangerous side effects associated with Corona virus, as well as the high level of cholesterol and triglycerides in the blood. Therefore, it has become necessary to use medicinal plants that are biologically safe and containing anti-clotting compound. Feijoa sellowiana represents a prolific source diverse compounds that may have thrombolytic activity. Therefore, the main research point is the production and scaling up of a target contents that have anticoagulants by using biotechnological techniques; calli production, and bioreactors and assessed their activity through in-vivo study. Murashige and Skoog (MS) medium enriched with varying concentrations of benzyl adenine (BA) and naphthalene acetic acid (NAA) was used to cultivate calli and cell suspension cultures from F. sellowiana seeds. Bioreactors were employed to boost active constituent's production. Moreover, the bioreactor physical factors such as effect of controlled or uncontrolled pH medium were investigated. The leaves of the main plant were extracted by ethanol 70% and polar and non-polar extracts were also prepared. The ethanol extract of calli and cells resulting from bioreactors were also prepared. All prepared extracts were subjected to chemical analysis by HPLC, in-vitro antioxidant assays, in-vivo anticoagulant activity and histopathological examination. Calli and cell suspension cultures were produced by using MS medium fortified with 1 mg/L BA+ 0.1 mg/L NAA. It was found that culturing of cell cultures in a bioreactor with uncontrolled pH and aeration at the value of 0.5 L/min gave the maximum and economical fresh and dry weights of the plants. After evaluation of all extracts; it was found that the calli ethanol extract for each plant was the highest value of total phenolic and total flavonoid contents either quantitatively or qualitatively. All extracts of Feijoa had antioxidant activity. The IC₅₀ of the DPPH of Feijoa calli extract was 13.45 μg/mL, it was also confirmed by FRAP and ABTs values. Feijoa calli extract decreased platelet aggregation by suppression of thrombin, extended aPTT, PT, bleeding and clotting times. It was safer than warfarin medication. From these findings the authors can conclude that Feijoa had highly anticoagulant activity and the calli production achieved the goal of the enhancement of the phenolic constituent and thus their activity.

Special Issue "COVID-19 and Thrombosis"

Since the pandemic began, an association among COVID-19 and venous thromboembolism has been reported, in particular for inpatients [...].

Nanoprotection from SARS-COV-2: would nanotechnology help in Personal Protection Equipment (PPE) to control the transmission of COVID-19?

The coronavirus disease 2019 (COVID-19) has caused a worldwide outbreak. The severe acute respiratory syndrome coronavirus 2 virus can be transmitted human-to-human through droplets and close contact where personal protective equipment (PPE) is imperative to protect the individuals. The advancement of nanotechnology with significant nanosized properties can confer a higher form of protection. Incorporation of nanotechnology into facemasks can exhibit antiviral properties. Nanocoating on surfaces can achieve self-disinfecting purposes and be applied in highly populated places. Moreover, nano-based hand sanitizers can confer better sterilizing efficacies with low skin irritation as compared to alcohol-based hand sanitizers. The present review discusses the incorporation of nanotechnology into nano-based materials and coatings in facemasks, self-surface disinfectants and hand sanitizers, in the hope to contribute to the current understanding of PPE to combat COVID-19.