Methods to Quantify Nanomaterial Association with, and Distribution across, the Blood-Brain Barrier in Vivo

The role and functional anatomy of the blood-brain barrier (BBB) is summarized to enable the investigator to appropriately address evaluation of nanomaterial interaction with, and distribution across, it into brain tissue (parenchyma). Transport mechanisms across the BBB are presented, in relation to nanomaterial physicochemical properties. Measures and test substances to assess BBB integrity/disruption/permeation are introduced, along with how they are used to interpret the results obtained with the presented methods. Experimental pitfalls and misinterpretation of results of studies of brain nanomaterial uptake are briefly summarized, that can be avoided with the methods presented in this chapter. Two methods are presented. The in situ brain perfusion technique is used to determine rate and extent of nanomaterial distribution into the brain. The capillary depletion method separates brain parenchymal tissue from the endothelial cells that contribute to the BBB. It is used to verify nanomaterial brain tissue entry. These methods are best used together, the latter refining the results obtained with the former. Details of the materials and equipment needed to conduct these methods, and description of the procedures and data interpretation, are provided

Kinetics of functionalised carbon nanotube distribution in mouse brain after systemic injection: Spatial to ultra-structural analyses.

Earlier studies proved the success of using chemically functionalised multi-walled carbon nanotubes (f-MWNTs) as nanocarriers to the brain. Little insight into the kinetics of brain distribution of f-MWNTs in vivo has been reported. This study employed a wide range of qualitative and quantitative techniques with the aim of shedding the light on f-MWNT's brain distribution following intravenous injection. γ-Scintigraphy quantified the uptake of studied radiolabelled f-MWNT in the whole brain parenchyma and capillaries while 3D-single photon emission computed tomography/computed tomography imaging and autoradiography illustrated spatial distribution within various brain regions. Raman and multiphoton luminescence together with transmission electron microscopy confirmed the presence of intact f-MWNT in mouse brain, in a label-free manner. The results evidenced the presence of f-MWNT in mice brain parenchyma, in addition to brain endothelium. Such information on the rate and extent of regional and cellular brain distribution is needed before further implementation into neurological therapeutics can be made.journal articleresearch support, non-u.s. gov't2016 Feb 282015 12 30importe

Coulomb dissociation of O-16 into He-4 and C-12

We measured the Coulomb dissociation of O-16 into He-4 and C-12 within the FAIR Phase-0 program at GSI Helmholtzzentrum fur Schwerionenforschung Darmstadt, Germany. From this we will extract the photon dissociation cross section O-16(alpha,gamma)C-12, which is the time reversed reaction to C-12(alpha,gamma)O-16. With this indirect method, we aim to improve on the accuracy of the experimental data at lower energies than measured so far. The expected low cross section for the Coulomb dissociation reaction and close magnetic rigidity of beam and fragments demand a high precision measurement. Hence, new detector systems were built and radical changes to the (RB)-B-3 setup were necessary to cope with the high-intensity O-16 beam. All tracking detectors were designed to let the unreacted O-16 ions pass, while detecting the C-12 and He-4

Effect of Sr-substitution on the structural and dielectric properties of LaFeO3 perovskite materials

The study aims to investigate the structural and dielectric properties of perovskite La1−xSrxFeO3 (x = 0.1, 0.2, 0.3, and 0.4) synthesized by sol–gel and sintering methods. X-ray diffraction (XRD), transmission electron microscopy (TEM), and LCR-Meter were used to identify the phase, crystallography parameters, morphology, particle size, and electrical behavior of the synthesized perovskite materials. The samples showed a single-phase orthorhombic crystal structure with Pbnm space group. Sr-substitution induced the volume unit cell and crystallite size to decrease. The synthesized nanoparticles were uniform and homogeneous with the particle size less than 200nm. Impedance spectroscopy (IS) was used to explain the electrical behavior as a function of frequency (100Hz to 1MHz) at various temperatures (300–373K). The presence of small polarons as charge carriers within the grain and grain boundary were elucidated from the electrical conductivity experiments. Sr-substitution caused the dielectric constant and electronic conductivity to increase with the highest values obtained from La1−xSrxFeO3 (x=0.4)

Development of seedless and Mal Secco tolerant mutant lemons through budwood irradiation

Mal secco (caused by Phoma tracheiphila (Petri) Kantsch. and Gik.) is the most destructive fungal disease of lemon plantations worldwide and seedless lemons would be preferred by most consumers. Five dosage levels, 0, 3, 5, 7, and 9 kiloradian (krad), of cobalt (Co-60) gamma irradiation were applied to budstick of 'Kutdiken' lemon (Citrus limon (L.) Burm. f.) clone KT-2A. Mutations were stabilized in three vegetative generations. Three hundred fifty-eight and 478 M1V3 (mutation one and vegetation three) plants were evaluated for seed number and mal secco tolerance in the field and the greenhouse, respectively. LD50 was around 5 krad gamma irradiation for 'Kutdiken' lemon. The seed number varied from 0 to 34 per fruit. The level of mal secco tolerance also varied significantly among the plants from 1.0 (no symptom) to 4.3 (high level of disease occurance). The stable seedless and mal secco tolerant plants were obtained from 5 and 7 krad irradiation: the three mutants from 5 krad irradiation gave more lemon-like fruits, while 7 krad irradiation caused altered tree morphology and early maturation of fruits. This study shows considerable potential for lemon cultivar improvement aiming to obtain seedless and mal secco tolerant lemons. (c) 2006 Elsevier B.V. All rights reserved

Multiphoton luminescence imaging of chemically functionalized multi-walled carbon nanotubes in cells and solid tumors

A simplified scheme showing the non-linear photoluminescence properties of f-MWNTs and their potential use as imaging tools in cells and tumors.</p