ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
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 (ÑÐ=7.2) and Sabouraud dextrose broth (ÑÐ=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 (â¼by 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.
