Many nano/microparticles (n/µP), to which our body is exposed, have no physiological way of removal. Our immune system sense these “small particulate objects”, and tries to decrease their harmfulness. Since oxidation, phagocytosis and other methods of degradation do not work with small, chemically resistant, and hydrophobic nanoparticles (nP). This applies to soot from air pollution, nano-diamonds from cosmic impact, polishing and related machines, synthetic polymers, and dietary n/µP. Our body tries to separate these from the surrounding tissue using aggregates from neutrophil extracellular traps (NETs). This effectively works in soft tissues where n/µP are entrapped into granuloma-like structures and isolated. The interactions of hydrophobic nanocrystals with circulating or ductal patrolling neutrophils and the consequent formation of occlusive aggregated NETs (aggNETs) are prone to obstruct capillaries, bile ducts in gallbladder and liver, and many more tubular structures. This may cause serious health problems and often fatality. Here we describe how specific size and surface properties of n/µP can activate neutrophils and lead to aggregation-related pathologies. We discuss “natural” sources of n/µP and those tightly connected to unhealthy diets. 

УДК 578.834:616-076-092.4:57.02:599.323.42 

Анотація. Наведено перші результати досліджень по створенню експериментальної моделі коронавірусної інфекції COVID-19 на лабораторних хом’яках лінії P. Roborovski. Тварин інфікували інтраназально біоматеріалом, взятим з епітелію носоглотки від хворих на COVID-19 з підтвердженим у них діагнозом шляхом експрес тестування з використанням Antigen Detection Kit (NEWGENE Bioengineering). Виявлено зростання температури тіла у піддослідних тварин. Гістологічне дослідження тканин легень інфікованих хом’яків на 5-ту добу спостереження виявив у них наявність набряку, крововиливів, лейкоцитарної інфільтрації, зменшення просвіту альвеол та інших ознак, які притаманні коронавірусній інфекції на її ранній стадії розвитку. Імуногістохімічний аналіз цих взірців легень з використанням моноклональних антитіл до нуклеокапсиду коронавірусу (X-223) та аналіз конфокальною мікроскопією субклітинних компонентів показав локалізацію вірусних антигенів у складі вакуоляризованих клітин інтерстицію легеневої тканини, що є молекулярним підтвердження наявності коронавірусних антигенів в легенях хом’яків. Створена експериментальна модель може бути використана для вивчення патогенезу COVID-19 та доклінічних випробовувань імунобіологічних та лікувально-профілактичних препаратів при цій інфекції.

Abstract. The first results of research on the creation of an experimental model of the COVID-19 coronavirus infection on laboratory hamsters of the P. Roborovski line are presented. Animals were infected intranasally with biomaterial taken from the nasopharyngeal epithelium of patients with a confirmed diagnosis of COVID- 19 by rapid testing using the Antigen Detection Kit (NEWGENE Bioengineering). An increase in body temperature was detected in experimental animals. Histological examination of lung tissues of infected hamsters on the 5th day of observation revealed the presence of edema, hemorrhages, leukocyte infiltration, reduction of alveolar lumen and other signs that are characteristic of coronavirus infection in its early stage of development. Immunohistochemical analysis of these lung samples using monoclonal antibodies to the nucleocapsid of the coronavirus (X-223) and analysis of subcellular components by confocal microscopy showed the localization of viral antigens in vacuolarized cells of the interstitial lung tissue, which is molecular confirmation of the presence of coronavirus antigens in the lungs of hamster tissues. The created experimental model can be used to study the pathogenesis of COVID-19 and preclinical tests of immunobiological and therapeutic and preventive drugs for this infection.

The demand for dependable near-infrared (NIR) probes, capable of sustained fluorescence within living systems and facile conjugation with biomolecules like antibodies and proteins, has been significantly on the rise, attributed to the substantial rise in the use of NIR imaging techniques and devices, with extensive integration into clinical diagnostics. Antibody conjugates are vital for targeted and selective bioimaging, enabling precise visualization of specific biomolecules within complex biological systems. Their multiplexing capability allows simultaneous detection of multiple targets, while their dynamic imaging capability enables real-time monitoring of cellular processes. Clinically, antibody conjugates have significant applications in disease prognosis, diagnosis, and monitoring. In this work, we report the synthesis of a new symmetrical NIR squaraine dye (SQ-58) with multiple carboxy anchoring groups for ease of coupling with antibodies. The dye showed decreased absorption and fluorescence intensity in phosphate buffer (PB) due to enhanced dye-aggregate formation. However, in the presence of bovine serum albumin (BSA) in PB, SQ-58 showed an enhanced fluorescence signal along concentrations of BSA. SQ-58 showed no cytotoxicity when tested in white laboratory mice while providing strong fluorescence when injected in vivo. Conjugation of SQ-58 through the carboxylic groups to the isotypic mouse IgG antibodies (IgG-SQ-58) resulted in uniform distribution of the targeted molecule in the whole cardiovascular system. The NIR signal of IgG-SQ-58 was stable for at least 7 days allowing the possibility of long-term imaging. Conjugation of SQ-58 to antibodies raised against NK-Ly lymphoma tumor cells allowed efficient discrimination of tumor cells grown in the abdomen of laboratory mice. Thus, to the best of our knowledge, we report for the first time a biocompatible NIR dye, SQ-58, that can be easily conjugatable to biomolecules, and its antibody conjugates for a wide range of bioimaging applications.

UDC 616-018: 616-097

This study addresses the current need for vaccine adjuvants able to induce an immune response to novel or mutated pathogens. It exploits the ability of nanodiamonds (ND) to induce the formation of neutrophil extracellular traps (NETs) triggering inflammation, accompanied by immune response to co-injected
antigens. Hydrophobic nanodiamonds 10 nm in diameter were covered with 194 a.a. sequence of the receptorbinding domain of Spike protein of SARS-CoV-2 via passive adsorption. It was shown that antigen-covered ND induce activation of human neutrophils and stimulate NETs formation and ROS production. When used for immunization antigen-covered ND induce a long-lasting immune response in mice with prevailing IgG1 among antibody subclasses. The injected nanoparticles were sequestered by NETs and safely covered with connective tissues when examined 1 year after injection.