RESUMO
Cell therapy is at the forefront of biomedicine in oncology and regenerative medicine. However, there are still significant challenges to their wider clinical application such as limited efficacy, side effects, and logistical difficulties. One of the potential approaches that could overcome these problems is based on extracellular vesicles (EVs) as a cell-free therapy modality. One of the major obstacles in the translation of EVs into practice is their low yield of production, which is insufficient to achieve therapeutic amounts. Here, we evaluated two primary approaches of artificial vesicle induction in primary T cells and the SupT1 cell line-cytochalasin B as a chemical inducer and ultrasonication as a physical inducer. We found that both methods are capable of producing artificial vesicles, but cytochalasin B induction leads to vesicle yield compared to natural secretion, while ultrasonication leads to a three-fold increase in particle yield. Cytochalasin B induces the formation of vesicles full of cytoplasmic compartments without nuclear fraction, while ultrasonication induces the formation of particles rich in membranes and membrane-related components such as CD3 or HLAII proteins. The most effective approach for T-cell induction in terms of the number of vesicles seems to be the combination of anti-CD3/CD28 antibody activation with ultrasonication, which leads to a seven-fold yield increase in particles with a high content of functionally important proteins (CD3, granzyme B, and HLA II).
RESUMO
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.
RESUMO
The unusual temperature behavior of the electron spin resonance (ESR) spectra and magnetic properties are experimentally observed in copper(II) complexes with a dendritic ligand based on the Boltorn H30 polymer (Perstorp Specialty Chemicals AB, Sweden) functionalized with fumaric acid residues in a molar ratio of 1:6. The ESR spectra at low temperatures show signs of transition to higher spin states at temperatures below 8-10 K, and the temperature dependences of the integral ESR signal intensities and magnetic susceptibility show the positive deviation from the Curie-Weiss law, thereby pointing to the presence of ferromagnetic exchange interactions in the system under study. The values of the exchange interaction parameters are calculated by quantum-chemical simulation of the possible structure of the copper(II) complex when assuming the formation of trinuclear coordination sites embedded in the hyperbranched polymer structure. The results of density functional theory calculations indicate the possibility of ferromagnetic exchange through carboxylate bridges in the trinuclear magnetic clusters, and the calculated values of the exchange interaction parameters make it possible to construct theoretical curves of the temperature dependence of the effective magnetic moment, which satisfactorily fit the experimental data, especially considering that polymers are characterized by disperse molecular weights and chemical structures.
RESUMO
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.