[The organization of pre-clinical studies of bactericidal and wound healing effects of the impulse photoherapy device "Zarya"].

The purpose of the study is to determine therapeutic effectiveness of the pulsed high intensity optical irradiation device "Zarya" exemplified by treatment of model wounds in laboratory animals and to compare with traditional methods of wound treatment. The prototype of "Zarya" device was used whose operating principle was based on pulsed irradiation of affected areas with high intensity optical radiation in continuous spectrum generated by pulsed xenon lamp. The therapeutic effect of the "Zarya" device was compared with effectiveness of the certified medical ultraviolet irradiator based on low-pressure mercury lamp and also with known wound-healing and antibacterial medication Levomekol ointment. The mature male rats of Wistar line were used in the study. The animals were distributed to 4 groups: group 1 was irradiated by "Zarya" device, group 2 was irradiated by low-pressure mercury lamp, group 3 was treated with Levomekol ointment and group 4 was exposed to no exposure. The linear wound was modeled according to the standard method under ether anesthesia. The therapeutic procedures were applied daily during 7 days. The bactericidal effect was studied on the basis of smears from wound onto flora on the 2nd, 5th and 7th day. On the 8th day the animals were subjected to euthanasia. It was established that "Zarya" device application permits to reduce considerably both duration of therapeutic procedures and therapy course in general and also to achieve more pronounced bactericidal effect. The obtained data is supposed to be used for development of program of clinical trials.

Mono-BHT heteroleptic magnesium complexes: synthesis, molecular structure and catalytic behavior in the ring-opening polymerization of cyclic esters.

Numerous heteroleptic 2,6-di-tert-butyl-4-methylphenolate (BHT) magnesium complexes have been synthesized by treatment of (BHT)MgBu(THF)2 with various alcohols. Molecular structures of the complexes have been determined by X-ray diffraction. The magnesium coordination number in [(BHT)Mg(µ-OBn)(THF)]2 (3) and [(BHT)Mg(µ-O-tert-BuC6H4)(THF)]2 (4) is equal to 4. Complexes formed from esters of glycolic and lactic acids, [(BHT)Mg(µ-OCH2COOEt)(THF)]2 (5) and [(BHT)Mg(µ-OCH(CH3)COOCH2COOtBu)(THF)]2 (6) contain chelate fragments with pentacoordinated magnesium. Compounds 3-6 contain THF molecules coordinated to magnesium atoms. Complex {(BHT)Mg[µ-O(CH2)3CON(CH3)2]}2 (7) does not demonstrate any tendency to form an adduct with THF. It has been experimentally determined that complexes 3 and 5 are highly active catalysts of lactide polymerization. The activity of 4 is rather low, and complex 7 demonstrates moderate productivity. According to DOSY NMR experiments, compounds 3 and 5 retain their dimeric structures even in THF. The free energies of model dimeric [(DBP)Mg(µ-OMe)(Sub)]2 and monomeric (DBP)Mg(OMe)(Sub)2 products on treatment of [(DBP)Mg(µ-OMe)(THF)]2 with a series of σ-electron donors (Sub) have been estimated by DFT calculations. These results demonstrate that the substitution of THF by Sub in a dimeric molecule is an energetically allowed process, whereas the dissociation of dimers is energetically unfavorable. DFT modeling of ε-CL and (dl)-lactide ROP catalyzed by dimeric and monomeric complexes showed that a cooperative effect of two magnesium atoms occurs within the ROP for binuclear catalytic species. A comparison of the reaction profiles for ROP catalyzed by binuclear and mononuclear species allowed us to conclude that the binuclear mechanism is favorable in early stages of ROP initiated by dimers 3 and 5.