Oxygen therapy alternatives in COVID-19: From classical to nanomedicine

Copper-Based Metal-Organic Framework as a Potential Therapeutic Gas Carrier: Optimization, Synthesis, Characterization, and Computational Studies

The broad spectrum of health conditions and the global pandemic, leading to inadequate medical oxygen supply and management, has driven interest in developing porous nanocarriers for effective oxygenation strategies. We aim to develop an injectable oxygen carrier with regard to biocompatibility, safety, prehospital availability, and universal applicability. In this study, we have tried to identify important functional sites on metal-organic frameworks (MOFs) for gas binding with the help of Grand canonical Monte Carlo simulation. We have synthesized a copper-based MOF (Cu-BTC) with a 1,3,5-benzenetricarboxylic acid linker through a solvothermal approach as a competent porous adsorbent for oxygen storage and delivery. To optimize process variables, we performed statistical analysis using response surface methodology. A quadratic model was developed to study the interaction between independent variables and the response (i.e., maximizing surface area), whose adequacy is validated by the correlation between experimental and predicted values using the ANOVA method. The synthesized Cu-BTC, before and after oxygen loading, was characterized using X-ray diffraction, surface area, along with pore distribution measurement, particle size analysis, scanning electron microscopy, transmission electron microscopy, and gas adsorption studies. The Cu-BTC MOF exhibited an oxygen uptake of 4.6 mmol g-1, the highest among all the oxygen carriers reported in the literature under the same operating conditions. Overall, our findings suggest that this synthesized Cu-BTC with high surface area (1389 m2 g-1), high porosity, optimum oxygen uptake, and good biocompatibility would show potential toward efficient storage and delivery (direct to the targeted site) of medical oxygen to raise the blood oxygen saturation level.

Systemically injected oxygen within rapidly dissolving microbubbles improves the outcomes of severe hypoxaemia in swine

Acute respiratory failure can cause profound hypoxaemia that leads to organ injury or death within minutes. When conventional interventions are ineffective, the intravenous administration of oxygen can rescue patients from severe hypoxaemia, but at the risk of microvascular obstruction and of toxicity of the carrier material. Here we describe polymeric microbubbles as carriers of high volumes of oxygen (350-500 ml of oxygen per litre of foam) that are stable in storage yet quickly dissolve following intravenous injection, reverting to their soluble and excretable molecular constituents. In swine with profound hypoxaemia owing to acute and temporary (12 min) upper-airway obstruction, the microbubble-mediated delivery of oxygen led to: the maintenance of critical oxygenation, lowered burdens of cardiac arrest, improved survival, and substantially improved neurologic and kidney function in surviving animals. Our findings underscore the importance of maintaining a critical threshold of oxygenation and the promise of injectable oxygen as a viable therapy in acute and temporary hypoxaemic crises.

Advanced biopolymeric materials and nanosystems for RNA/DNA vaccines: a review

The post COVID-19 pandemic era has emerged with more efficient vaccines, all based on genetic materials. However, to expand the use of nucleic components as vaccines, a new generation of nanosystems particularly constructed to increase RNA/DNA stability, half-life and facilitate administration are still required. This review highlights novel developments in mRNA and pDNA vaccines formulated into nanostructures exclusively composed by biopolymeric materials. Recent advances suggest that a new generation of vaccines may arise by adapting the structural features of biopolymers with the effectiveness of nucleic acids. The advantages offered by biopolymers, such as increased stability and targeting ability may cause a revolution in the immunization field for offering promptly adaptable and effective formulations for worldwide distribution.

COVID-19 in Children: Molecular Profile and Pathological Features

Although the World Health Organization has declared the end of the COVID-19 pandemic, doctors continue to register new cases of the disease among both adults and children. Unfortunately, the course of COVID-19 in children can have a severe form, with death being a potential outcome. The absence of published works discussing the pathological morphology of COVID-19 in children prevents the objective analysis of the disease's pathogenesis, including among the adult population. In this vein, the objective of our study is to identify the morphological features of the lungs' involvement and evaluate virus-host interactions in the case of COVID-19 in patients at a pediatric medical practice. We present the results of the study of the lungs of three children who died due to COVID-19, highlighting the predominant involvement of their respiratory organs at different stages of the disease (5, 21, and 50 days). This article presents data obtained from histopathological and immunohistochemical investigations, taking into account the results of clinical and laboratory indicators and intravital and postmortem SARS-CoV-2 PCR investigations. The common finding of all of the examined COVID-19 cases is the involvement of the endothelium in microcirculation vessels, which are considered to be a primary target of various pathogenic influencing factors. We also discuss both the significance of apoptosis as a result of virus-host interactions and the most likely cause of endothelium cell destruction. The results of this study could be useful for the development of endothelium-protective therapy to prevent the progression of disseminated intravascular coagulation syndrome.