Two-photon absorption properties of multipolar triarylamino/tosylamido 1,1,4,4-tetracyanobutadienes.

The synthesis and characterization of four new tetracyanobutadiene (TCBD) derivatives (1, 3c and 4b-c) incorporating tosylamido and 4-triphenylamino moieties are reported. Along with those of five closely related or differently branched TCBDs derivatives (2, 3a-b, 4c and 5), their linear and (third-order) nonlinear optical properties were investigated by electronic absorption spectroscopy and Z-scan measurements. Among these compounds, the tri-branched compounds 3c and 5 are the most active two-photon absorbers, with effective cross-sections of 275 and 350 GM at 900 nm, respectively. These properties are briefly discussed with the help of DFT calculations, focussing on structural and electronic factors, and contextualized with results obtained previously for related compounds.

Efficient transfection of Xenobiotic Responsive Element-biosensor plasmid using diether lipid and phosphatidylcholine liposomes in differentiated HepaRG cells.

In this study, we evaluated cationic liposomes prepared from diether-NH2 and egg phosphatidylcholine (EPC) for in vitro gene delivery. The impact of the lipid composition, i.e. the EPC and Diether-NH2 molar ratio, on in vitro transfection efficiency and cytotoxicity was investigated using the human HEK293T and hepatoma HepaRG cells known to be permissive and poorly permissive cells for liposome-mediated gene transfer, respectively. Here, we report that EPC/Diether-NH2-based liposomes enabled a very efficient transfection with low cytotoxicity compared to commercial transfection reagents in both HEK293T and proliferating progenitor HepaRG cells. Taking advantage of these non-toxic EPC/Diether-NH2-based liposomes, we developed a method to efficiently transfect differentiated hepatocyte-like HepaRG cells and a biosensor plasmid containing a Xenobiotic Responsive Element and a minimal promoter driving the transcription of the luciferase reporter gene. We demonstrated that the luciferase activity was induced by a canonical inducer of cytochrome P450 genes, the benzo[a]pyrene, and two environmental contaminants, the fluoranthene, a polycyclic aromatic hydrocarbon, and the endosulfan, an organochlorine insecticide, known to induce toxicity and genotoxicity in differentiated HepaRG cells. In conclusion, we established a new efficient lipofection-mediated gene transfer in hepatocyte-like HepaRG cells opening new perspectives in drug evaluation relying on xenobiotic inducible biosensor plasmids.

Linear Optical and Third-Order Nonlinear Optical Properties of Some Fluorenyl- and Triarylamine-Containing Tetracyanobutadiene Derivatives.

The synthesis and characterization of four new tetracyanobutadiene (TCBD) derivatives (1-3 and 2') incorporating 2- or 2,7-fluorenyl and diphenylamino moieties are reported. The electroactivity of 1-3 and 2' was studied by cyclic voltammetry (CV), while the linear optical and (third-order) nonlinear optical (NLO) properties were investigated by electronic spectroscopy and Z-scan studies, respectively. All experimental investigations were rationalized by DFT computations, providing an insight into the electronic structure of these derivatives and on their application potential. We show that these derivatives are nonluminescent in solution at ambient temperatures, but become fluorescent in solvent glasses. This finding constitutes an unprecedented observation for TCBD derivatives. Also, we show by Z-scan studies that these derivatives behave as two-photon absorbers in the near-IR range (800-1050 nm). These third-order NLO properties are discussed and compared with those of their alkynyl precursors (4-6), which have been investigated by two-photon excited fluorescence (TPEF).