The synthesis and characterization of two liquid-crystalline ionically self-assembled (ISA) materials obtained by the complexation of an anionic perylene bisimide dye with cationic chiral surfactants is described for the first time. The influence of the chiral nature of the surfactants on the supramolecular organization of the resulting ISA materials is investigated. Circular dichroism (CD) spectroscopy shows that, upon complexation, the molecular chirality of the surfactants is expressed in the bisimide chromophore through the ionic linkage, clearly indicating that the surfactants act as structure-inducing moieties within the superstructures in both solution and the solid state. In solution, the complexes form left-handed helically stacked architectures. In the solid state, both systems are highly ordered and exhibit lamellar morphologies. The well-defined structures presented here are the first examples of ISA materials that show supramolecular chirality.
Aim:We report the physicochemical analysis of nanosystems intended for cardiovascular applications and their toxicological characterization in static and dynamic cell culture conditions. Methods: Size, polydispersity and ζ-potential were determined in 10 nanoparticle systems including liposomes, lipid nanoparticles, polymeric and iron oxide nanoparticles. Nanoparticle effects on primary human endothelial cell viability were monitored using real-time cell analysis and live-cell microscopy in static conditions, and in a flow model of arterial bifurcations. Results & conclusions: The majority of tested nanosystems were well tolerated by endothelial cells up to the concentration of 100 μg/ml in static, and up to 400 μg/ml in dynamic conditions. Pilot experiments in a pig model showed that intravenous administration of liposomal nanoparticles did not evoke the hypersensitivity reaction. These findings are of importance for future clinical use of nanosystems intended for intravascular applications.
We herein developed a micro-CT method using the innovative contrast agent ExiTron™ MyoC 8000 to longitudinally monitor cardiac processes in vivo in small animals. Experiments were performed on healthy mice and mice with myocardial infarction inflicted by ligation of the left anterior descending artery. Time-dependent signal enhancement in different tissues of healthy mice was measured and various contrast agent doses were investigated so as to determine the minimum required dose for imaging of the myocardium. Due to its ability to be taken up by healthy myocardium but not by infarct tissue, ExiTron MyoC 8000 enables detection of myocardial infarction even at a very low dose. The signal enhancement in the myocardium of infarcted mice after contrast agent injection was exploited for quantification of infarct size. The values of infarct size obtained from the imaging method were compared with those obtained from histology and showed a significant correlation (R2 = 0.98). Thus, the developed micro-CT method allows for monitoring of a variety of processes such as cardiac remodeling in longitudinal studies.
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