Аннотация:Nano- and microparticles enter the body through the respiratory airways, the digestive system, or form as biominerals in the gall bladder, salivary glands, urinary bladder, kidney, diabetic pancreas. Calcium, magnesium and phosphate ions can precipitate from biological fluids in the presence of mucin as hybrid nanoparticles. Calcium carbonate nanocrystallites also trap mucin and are assembled to hybrid microparticles. Both mucin and calcium carbonate polymorphs (calcite, aragonite and vaterite) are known to be components of such biominerals as gallstones which provoke inflammatory reactions. Our study was aimed at evaluation of neutrophil activation by hybrid vaterite-mucin microparticles (CCM). Vaterite microparticles (CC) and CCM were prepared under standard conditions. Diameter of CC and CCM was 3.3±0.8µm and 5.8±0.7µm and ƺ-potential -1±1 mV and -7±1 mV, respectively. CC microparticles injured less than 2 % of erythrocytes in 2 hours at 1.5 mg mL-1 and no hemolysis was detected with CCM; this let us exclude direct damage of cellular membranes by microparticles. Activation of neutrophils was analysed by luminol- and lucigenin-dependent chemiluminescence (Lum-CL and Luc-CL), by cytokine gene expression (IL-6, IL-8, IL-10) and release (IL-1β, IL-6, IL-8, IL-10, TNF-α) and by light microscopy of stained smears. There was 10-fold and more increase in amplitude of Lum-CL and Luc-CL after stimulation of neutrophils with CCM relative to CC. Adsorption of mucin onto prefabricated CC microparticles also contributed to activation of neutrophil CL unlike mucin adsorption onto yeast cell walls (zymosan); adsorbed mucin partially supressed stimulated by zymosan production of oxidants by neutrophils. Preliminary treatment of CCM with 0.1-10mM NaOCl decreased subsequent activation of Lum-CL and Luc-CL of neutrophils depending on the used NaOCl concentration, presumably because of the surface mucin oxidation. Based on the results of ELISA, incubation of neutrophils with CCM downregulated IL-6 production but upregulated that of IL-8. IL-6 and IL-8 gene expression in neutrophils was not affected by CC or CCM according to RT2-PCR data, which means that post-translational regulation was involved. Light microscopy revealed adhesion of CC and CCM microparticles to the neutrophils; CCM increased neutrophil aggregation with tendency to form neutrophil extracellular traps (NETs). We came to a conclusion that the main features of neutrophil reaction to mucin-vaterite hybrid microparticles are increased oxidants production, cell aggregation and NETs-like structures formation but without significant cytokines release (except for IL-8). This effect of mucin is not anion-specific since particles of powdered kidney stone (mainly calcium oxalate) in the present study or calcium phosphate nanowires in our previous report also activated Lum-CL and Luc-CL response of neutrophils after mucin sorption.