The effects of natural clinoptilolite originated from the Transcarpathian region in the Western Ukraine and its composites doped with metal ions were studied toward: (1) cultured pseudo-normal mammalian cell and murine macrophages; (2) neutrophils of blood of healthy human donors; (3) mice immunized with model antigen; (4) mice under air-pouch model for estimation of microvasculature damage; (5) Candida albicans fungi. Silver doping enhanced cytotoxic action of natural clinoptilolite, while zinc doping did not do that. Clinoptilolite-Ag(NH₃)²⁺ was non-toxic for murine macrophages and moderately toxic for human HEК293 cells. Toxicity of clinoptilolite-Ag⁺ composite toward HEК293 cells was comparable with the effect in positive control. Natural clinoptilolite and its silver derivatives enhanced the humoral immune response in mice and the levels of antibodies were comparable with such levels at response to standard adjuvant, which, however, damaged the microvasculature in mice. Furthermore, natural and Ag-enriched clinoptilolite were capable of activating neutrophils with a release of neutrophil extracellular traps. Finally, we showed that both clinoptilolite-Ag(NH₃)²⁺ and clinoptilolite-Ag+ possessed much higher antifungal activity toward Candida albicans compared to such activity of the nonmodified clinoptilolite, while their doping with zinc did not show such enhancement. Thus, the Transcarpathian clinoptilolite possesses low toxicity toward mammalian cells and activates neutrophils in vitro, while silver doping enhanced the cytotoxicity of this material. Silver-doped derivatives demonstrated stimulating action on antibody production and the antifungal effect. Thus, the developed clinoptilolite-based composites are perspective for use as novel natural immuno-stimulators and antifungal agents.

 Keywords Clinoptilolite · Cytotoxicity · Immune-stimulation · Antifungal activity

UDC: 615.277.3:547.76].012:542.9

In vitro study and characterization of anticancer activity of new heterocyclic derivative N(5methyl[1,3,4]thiadiazol2yl)propionamide. Methods. The cell culture; MTT assay. Results. We synthesized N(5methyl[1,3,4]thiadiazol2yl)propionamide, which possessed diuretic, cardioprotective, and anti-inflammatory effects. Here, we investigated its cytotoxicity effect towards the tumor cell lines of various tissue origins: liver (HepG2), breast (MCF 7), lung (A549), cervical (KB3 1), and leukemia (HL 60) cells, as well as towards the non-tumor cells (НЕК293 and NIH3T3). The IC50 values of the synthesized compound for tumor cells were in the range of 9.4–97.6 μg/mL. We found that the human hepatocellular carcinoma HepG2 cells were the most sensitive to the action of N(5methyl[1,3,4]thiadiazol 2yl)propionamide with the IC 50 value of 9.4 μg/mL. The studied derivative slightly inhibited the growth of the pseudo normal HEK293 and NIH3T3 cells. Conclusions. The anti prolife rative activity of N(5methyl[1,3,4]thiadiazol2yl)propionamide dropped in the order: hepatocarcinoma > leukemia > breast carcinoma cells. Thus, we revealed in the molecule of N(5methyl[1,3,4]thiadiazol2yl)propionamide a combination of the diuretic, cardioprotec tive, anti-inflammatory and anticancer activities, which is of great significance for this agent
as a potent anticancer medicine

UDC 577.615.324-027.2.615.076

   Creation of novel remedies efficient in supporting wound healing remains an actual task in pharmacology. Hydrogels showed high efficiency in wound healing and tissue regeneration due to viscosity, elasticity and fluidity that provide them with functional characteristics similar to that in extracellular matrix. The aim of the study was to create chitosan-based hydrogels functionalized with different components (chondroitin-6-sulfate, hyaluronic acid, N-stearoylethanolamine) and to estimate their biocompatibility and biodegradability in vitro. For the first time, a lipid substance N-stearoylethanolamine (NSE) known as suppressor of pro-inflammatory cytokines expression was used as hydrogel component (1.95 mg/g). FTIR analysis confirmed the complexation of chitosan molecule with hyaluronate, chondroitin-6-sulfate, NSE. MTT-test and Trypan blue exclusion test were used to study hydrogels cytotoxicity towards human cells of different tissue origin. Biodegradability of hydrogels was evaluated using direct hydrogel contact with cells and cellindependent degradation. It was shown that chondroitin-6-sulfate (<2 mg/ml), hyaluronic acid (<2 mg/ml) and NSE (26 μg/ml) did not demonstrate significant toxic effects towards pseudonormal human cells of the MCF10A, HaCat, HEK293 lines and mouse cells of the Balb/3T3 line. The studied hydrogels were stable in saline solution, while in a complete culture medium containing 10% fetal bovine blood serum they underwent degradation in >24 h. The identified biodegradability of the chitosan-based hydrogels is important for the release of noncovalently immobilized NSE into biological medium. Further studies on laboratory animals with experimental wounds are expected to explore the potential of created hydrogels as anti-inflammatory
and wound-healing agents.
K e y w o r d s: chitosan hydrogels, chondroitin-6-sulfate, hyaluronic acid, N-stearoylethanolamine, FTIR analysis, human pseudonormal cells, toxicity, biodegradability