In Vitro and in Vivo Visualization and Trapping of Fluorescent Magnetic Microcapsules in a Bloodstream

Remote navigation and targeted delivery of biologically active compounds is one of the current challenges in the development of drug delivery systems. Modern methods of micro- and nanofabrication give us new opportunities to produce particles and capsules bearing cargo to deploy and possess magnetic properties to be externally navigated. In this work we explore multilayer composite magnetic microcapsules as targeted delivery systems in vitro and in vivo studies under natural conditions of living organism. Herein, we demonstrate magnetic addressing of fluorescent composite microcapsules with embedded magnetite nanoparticles in blood flow environment. First, the visualization and capture of the capsules at the defined blood flow by the magnetic field are shown in vitro in an artificial glass capillary employing a wide-field fluorescence microscope. Afterward, the capsules are visualized and successfully trapped in vivo into externally exposed rat mesentery microvessels. Histological analysis shows that capsules infiltrate small mesenteric vessels whereas large vessels preserve the blood microcirculation. The effect of the magnetic field on capsule preferential localization in bifurcation areas of vasculature, including capsule retention at the site once external magnet is switched off is discussed. The research outcome demonstrates that microcapsules can be effectively addressed in a blood flow, which makes them a promising delivery system with remote navigation by the magnetic field

Solar modulation of galactic cosmic rays during 2006-2015 based on PAMELA and ARINA data

Solar modulation of galactic protons with energies from 50 MeV up to dozens of GeV during July '06 - January '16 studied based on a data of the magnetic spectrometer PAMELA and scintillation spectrometer ARINA. This period is interesting because it covers the end of 23rd and current 24th cycles of solar activity, including the abnormally long transient period and change of the polarity of solar magnetic field

Molecular structure-device performance relationship in polymer solar cells based on indene-C-60 bis-adduct derivatives

Interfacial tension between two materials is a key parameter in determining their miscibility and, thus, their morphological behavior in blend films. In bulk heterojunction (BHJ)-type polymer solar cells (PSCs), control of the interfacial tension between the electron donor and the electron acceptor is critically important in order to increase miscibility and achieve optimized BHJ morphology for producing efficient exciton dissociation and charge transport. Herein, we report the synthesis of a series of indene-C-60 bis-adducts (ICBA) derivatives by modifying their end-groups with fluorine (FICBA), methoxy (MICBA) and bromine (BICBA) functional units. We systematically studied the effects of their structural changes on the blend morphology with poly(3-hexylthiophene) (P3HT) and their performance in the PSCs. The end-group modification of ICBA derivatives induced a dramatic change in their interfacial tensions with P3HT (i.e., from 4.9 to 8.3mN m(-1)), resulting in large variations in the power conversion efficiency (PCE) of the PSCs, ranging from 2.9 to 5.2%