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Oxidative stress induced by neutrophils and hypoxia in COVID-19 pneumonia leads to albumin modification. This may result in elevated levels of advanced oxidation protein products (AOPPs) and advanced lipoxidation end-products (ALEs) that trigger oxidative bursts of neutrophils and thus participate in cytokine storms, accelerating endothelial lung cell injury, leading to respiratory distress. In this study, sixty-six hospitalized COVID-19 patients with respiratory symptoms were studied. AOPPs-HSA was produced in vitro by treating human serum albumin (HSA) with chloramine T. The interaction of malondialdehyde with HSA was studied using time-resolved fluorescence spectroscopy. The findings revealed a significantly elevated level of AOPPs in COVID-19 pneumonia patients on admission to the hospital and one week later as long as they were in the acute phase of infection when compared with values recorded for the same patients 6- and 12-months post-infection. Significant negative correlations of albumin and positive correlations of AOPPs with, e.g., procalcitonin, D-dimers, lactate dehydrogenase, aspartate transaminase, and radiological scores of computed tomography (HRCT), were observed. The AOPPs/albumin ratio was found to be strongly correlated with D-dimers. We suggest that oxidized albumin could be involved in COVID-19 pathophysiology. Some possible clinical consequences of the modification of albumin are also discussed.

The unique plasmonic properties of the noble metal colloidal nanoparticles make them promising enhancement substrates for surface-enhanced Raman scattering. Obtaining of systems that provide ever-increasing enhancement of the Raman scattered light is a big challenge. Silver colloids studied here are prepared by LeeMeisel's method.Rhodamine 6G and rhodamine B are used as probe adsorbates. The raw colloids obtained in this way exhibit a characteristic extinction band proving surface plasmons excitation, but do not enhance the Raman signal.Theoretical calculations indicate that the extremely large electromagnetic eld is induced in the junctions between metallic nanostructures so some degree of their aggregation is necessary to achieve a sucient gain value. The addition of aggregating agents (KCl or HCl) leads to signicant changes in the extinction spectrum and to signicant increase in the intensity of surface-enhanced Raman scattering. The experiments show that chloride can not only promote the aggregation process but also eectively aect chemical mechanisms contributing to surface-enhanced Raman scattering.

Camptothecin (CPT) and its hydroxycamptothecin analogs are fluorescent compounds exhibiting strong anticancer properties. They exist in two forms: active lactone and inactive carboxylate. The deactivation proceeds via hydrolysis in neutral and base solutions. A serious limitation to the clinical application of CPT is the strong affinity of its carboxylate form to human serum albumin (HSA) which destabilizes its active lactone form. However, binding to membranes in blood improves the stability of the lactone form of CPT and its analogs. A high-throughput screening assay based on the steady-state fluorescence anisotropy method was used to determine the protein- and membrane-binding properties of 10 hydroxycamptothecin (10-OH-CPT), 7-ethyl-10-hydroxycamptothecin (SN-38) and 7-tert-butyldimethylsil-10-hydroxycamptothecin (DB-67). The relative affinities of hydroxycamptothecins to HSA and model membranes in the form of DMPC liposomes were determined, and DB-67 exhibited the most desirable properties including the highest affinity to membranes in its lactone form and low affinity to HSA in its carboxylate form.

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Surface-enhanced Raman scattering is the phenomenon where a huge increase of Raman scattering intensity from molecules situated close to the metal nanoobjects is observed. Our study is focused on the method of SERSactivation of silver nanoparticles and, in the future, the application of thus obtained SERS substrates for biomedical purposes. As expected, the intensity of Raman scattering from rhodamine 6G used here as a SERS probe strongly increase during the early stages of aggregation of silver sol. Moreover, the evolution of extinction spectra and changes in the degree of the colloid aggregation observed in DLS measurements point out that molecules of the dye do not participate passively in the aggregation process but greatly aect its course.

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