FITC-labeled LPS from Neisseria meningitidis can be used as a probe to follow the process of LPS incorporation into liposomal membrane and to study its interaction with a bilayer. The incorporation of FITC-LPS into the bilayer was proved by physicochemical methods as well as by liposomal LPS toxicity decrease in actinomycin D-sensitized mice. Fluorescence intensity increase was observed upon the insertion of FITC-LPS into the membrane of dehydration/rehydration vesicles and vesicles obtained by co-sonication of lipid suspension and FITC-LPS. Following FITC-LPS fluorescence polarization it was shown that the substance seems to be clusterized in the liposomal membrane starting from FITC-LPS/lipid molar ratio 1800.

To obtain nontoxic and highly immunogenic lipopolysaccharide (LPS) for immunization, we incorporated Neisseria meningitidis LPS into Uposomes. Native LPS and its salts were incorporated by the method of dehydration-rehydration of vesicles or prolonged cosonication. The most complete incorporation of LPS into Uposomes and a decrease in toxicity were achieved by the method of dehydration-rehydration of vesicles. Three forms of LPS (H+ form, Mg2e salt, and triethanolamine salt) showed different solubilties in water, the acidic form of LPS, with the most pronounced hydrophobic properties, being capable of practically complete association with liposomal membranes. An evaluation of the activity of liposomal LPS in vitro (by the Limulus amoebocyte test) and in vivo (by monitoring the pyrogenic reaction in rabbits) revealed a decrease in endotoxin activity of up to 1,000-fold. In addition, the pyrogenic activity of liposomal LPS was comparable to that of a meningococcal polysaccharide vaccine. Liposomes had a pronounced adjuvant effect on the immune response to LPS. Thus, the level of anti-LPS plaque-forming ceHls in the spleens of mice immunized with liposomal LPS was 1 order of magnitude higher and could be observed for a longer time (until day 21, i.e., the term of observation) than in mice immunized with free LPS. The same regularity was revealed in a study done with an enzyme-linked immunosorbent assay. This study also established that antibodies induced by immunization belonged to the immunoglobulin M and G classes, which are capable of prolonged circulation. Moreover, liposomal LPS induced a pronounced immune response in CBA/N mice (defective in B lymphocytes of the LyB-5+ subpopulation). The latter results indicate that the immunogenic action of liposomal LPS occurs at an

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Chronic kidney disease (CKD) is part of the modern pandemic of chronic, non-communicable diseases, which is one of the leading causes and causes of death among the world's population. CKD affects nearly 850 million people worldwide and is the 6th leading cause of death. In Bulgaria, the incidence is 12.8%, and 90% of the patients have advanced kidney disease. According to the summarized data of the National Statistical Institute (NSI) and the National Center for Public Health and Analysis at the Ministry of Health for 2018, urogenital diseases accounted for 1.4% of mortality in the country, and this percentage increased in 2019 by 1.7%. The reasons for this probably lie in the increasing frequency of risk factors among the population. In order to early detect the risk factors for CKD and the timely diagnosis of patients with hidden kidney disease and their further followup, in July 2020, the Clinic of Nephrology at the St. Marina University Hospital in Varna, supported by a project of the Medical University of Varna, conducted a free screening campaign for 147 people among the population of Dalgopol municipality. In addition, the campaign aimed to raise public awareness of CKD and renal replacement therapy methods (hemodialysis, peritoneal dialysis, and kidney transplantation). During the campaign, 58 participants (39%) were newly diagnosed with kidney disease. This indicates the lack of routine physical, imaging and laboratory tests and failure to diagnose kidney disease in its early stages. The financial burden that undiagnosed kidney problems, and subsequently end-stage renal disease, entail, puts even highly developed economies to a severe test. Screening and prevention can prevent chronic kidney disease, and where management strategies are in place, the incidence of end-stage renal disease is reduced.