Self-Assembling Metallocomplexes of the Amphiphilic 1,4-Diazabicyclo[2.2.2]octane Derivative as a Platform for the Development of Nonplatinum Anticancer Drugs.

New 1-cetyl-4-aza-1-azoniabicyclo[2.2.2]octane bromide complexes with copper(II) bromide and lanthanum(III) nitrate were characterized using dynamic light scattering and transmission electron microscopy, with self-assembly and the morphological behavior elucidated. For the lanthanum(III) nitrate complex, the 3D crystal structure was characterized using X-ray diffractometry. These metallosurfactants were tested as antitumor agents, and a high cytotoxic effect comparable with doxorubicin was revealed against the M-HeLa and A-549 cell lines. Both complexes were 2 times more active toward the MCF-7 cell line than the breast cancer drug tamoxifen. The cytotoxic mechanism of complexes is assumed to be related to the induction of apoptosis through the mitochondrial pathway.

Design of High-Relaxivity Polyelectrolyte Nanocapsules Based on Citrate Complexes of Gadolinium(III) of Unusual Composition.

Through nuclear magnetic relaxation and pH-metry, the details of the complexation of gadolinium(III) ions with citric acid (H4L) in water and aqueous solutions of cationic polyelectrolytes are established. It is shown that the presence of poly(ethylene imine) (PEI) in solution affects magnetic relaxation behavior of gadolinium(III) complexes with citric acid (Cit) to a greater extent than polydiallyldimethylammonium chloride (PDDC). A large increase in relaxivity (up to 50 mM-1s-1) in the broad pH range (4-8) is revealed for the gadolinium(III)-citric acid-PEI system, which is particularly strong in the case of PEI with the molecular weight of 25 and 60 kDa. In weakly acidic medium (pH 3-7), the presence of PEI results in the formation of two tris-ligand associates [Gd(H2L)3]3- and [Gd(H2L)2(HL)]4-, which do not exist in aqueous medium. In weakly alkaline medium (pH 7-10), formation of ternary complexes Gd(III)-Cit-PEI with the Gd(III)-to-Cit ratio of 1:2 is evidenced. Using transmission electron microscopy (TEM) and dynamic light scattering techniques (DLS), the formation of the particles with the size of 50-100 nm possessing narrow molecular-mass distribution (PDI 0.08) is determined in the solution containing associate of PEI with tris-ligand complex [Gd(H2L)2(HL)]4-.

TiLoop Bra Assisted Breast Reconstruction - Our Experience.

Additional covering of the lower pole with allomaterial or its synthetic analogues during immediate breast reconstruction is being perfomed at the N.N. Petrov National Medical Research Oncology Center, Ministry of Healthcare of Russian Federation for last 7 years. Initially, epidermal flap was the only option for lower pole coverage, later ADM was used as part of clinical approbation. Average complication rate ranges from 20-35% due to blood circulatory (supply) disorders. Since 2018, a titanized mesh (TiLoop Bra) been used as a additional coverage of the lower pole. Methods: From July 2018 to April 2019, 103 breast reconstructions were performed using TiLoop-BRA mesh. All operations were performed due to malignant tumors of breast, of which in 94 operations were performed for unilateral breast carcinoma, 9 for bilateral breast carcinoma.74 patients received neoadjuvant therapy, 31 received adjuvant therapy, 17 patients required radiation therapy. Results: Overall complications rates significally decreased. Complete loss of breast implant and mesh endoprosthesis 5.88%, Capsular contracture 17.65 %, Only mesh removal due to painful syndrome 5.88%,* Red breast * syndrome (by analogy with ADM) 5.88%.

A new surfactant-copper(ii) complex based on 1,4-diazabicyclo[2.2.2]octane amphiphile. Crystal structure determination, self-assembly and functional activity.

A new surfactant-copper(ii) complex [Cu(L)Br3] (where LBr is 1-cetyl-4-aza-1-azoniabicyclo[2.2.2]octane bromide) containing a transition metal in the head group has been synthesized and characterized. Physicochemical properties, thermal stability and 3D structure were determined using X-ray diffractometry, UV-vis spectroscopy, simultaneous thermogravimetry and differential scanning calorimetry combined with mass-spectrometry of evolved vapors. The study of the self-assembly and morphological features of associated structures was performed by potentiometry using a bromide ion selective electrode and fluorescence of pyrene and 1,6-diphenyl-1,3,5-hexatriene. The influence of the metal ion embedded into the surfactant structure on critical micelle concentration, degree of counterion binding, aggregation numbers and morphology of the associates was elucidated. High solubilizing capacity and complexation ability of the metal containing micelles with respect to Orange-OT hydrophobic dye and oligonucleotide were determined. Importantly, the functional properties of this metallosurfactant complex are much better compared to those of classical cationic surfactants bearing cyclic and acyclic head groups, LBr and the LBr-CuBr2 mixture. The new cationic metallosurfactant could be recommended for investigation in gene therapy.

Self-assembling systems based on quaternized derivatives of 1,4-diazabicyclo[2.2.2]octane in nutrient broth as antimicrobial agents and carriers for hydrophobic drugs.

Aggregation properties of mono (mono-CS) and dicationic (di-CS) surfactants, namely quaternised derivatives of 1,4-diazabicyclo[2.2.2]octane (DABCO), have been evaluated in water and in nutrient broths of different pH, i.e. in Hottinger broth (рН=7.2) and Sabouraud dextrose broth (рН=5.6). Aggregation capacity of surfactants was shown to be responsible for the solubilization properties of a complex composed of a hydrophobic probe (Sudan I) and a selected drug (quercetin), contributing to the antimicrobial activity of this surfactant system. The effect of N-methyl-d-glucamine (NmDg) additive on the antimicrobial activity of mono-CS, and its aggregation and solubilization parameters, has also been evaluated. A substantial decrease in critical micelle concentration (CMC) of cationic surfactants in nutrient broths (up to 60 times) has been reported. Twofold dilution of monocationic surfactant by NmDg slightly changed the CMC of surfactant; however, it provided a remarkable increase in solubilization capacity (∼by 4 times) and decrease in its toxicity. The data anticipate the potential use of DABCO quaternized derivatives as innovative non-toxic delivery systems for hydrophobic drugs.