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Lizarbe B.,Instituto Investigaciones Biomedicas Alberto Sols CSIC UAM | Benitez A.,Instituto Investigaciones Biomedicas Alberto Sols CSIC UAM | Benitez A.,Autonomous University of Madrid | Sanchez-Montanes M.,Autonomous University of Madrid | And 5 more authors.
NeuroImage | Year: 2013

Hypothalamic appetite regulation is a vital homeostatic process underlying global energy balance in animals and humans, its disturbances resulting in feeding disorders with high morbidity and mortality. The objective evaluation of appetite remains difficult, very often restricted to indirect measurements of food intake and body weight. We report here, the direct, non-invasive visualization of hypothalamic activation by fasting using diffusion weighted magnetic resonance imaging, in the mouse brain as well as in a preliminary study in the human brain. The brain of fed or fasted mice or humans were imaged at 7 or 1.5Tesla, respectively, by diffusion weighted magnetic resonance imaging using a complete range of b values (10

Saghi Z.,University of Cambridge | Saghi Z.,andalusian Center for Nanomedicine and Biotechnology | Holland D.J.,University of Cambridge | Leary R.,University of Cambridge | And 5 more authors.
Nano Letters | Year: 2011

In this paper, we apply electron tomography (ET) to the study of the three-dimensional (3D) morphology of iron oxide nanoparticles (NPs) with reactive concave surfaces. The ability to determine quantitatively the volume and shape of the NP concavity is essential for understanding the key-lock mechanism responsible for the destabilization of gold nanocrystals within the iron oxide NP concavity. We show that quantitative ET is enhanced greatly by the application of compressed sensing (CS) techniques to the tomographic reconstruction. High-fidelity tomograms using a new CS-ET algorithm reveal with clarity the concavities of the particle and enable 3D nanometrology studies to be undertaken with confidence. In addition, the robust performance of the CS-ET algorithm with undersampled data should allow rapid progress with time-resolved 3D nanoscale studies, 3D atomic resolution imaging, and cryo-tomography of nanoscale cellular structures. © 2011 American Chemical Society.

Le Guevel X.,andalusian Center for Nanomedicine and Biotechnology
IEEE Journal on Selected Topics in Quantum Electronics | Year: 2014

Metal (gold, silver, copper, platinum) quantum nano-clusters are an emerging family of fluorescent markers exhibiting unique photophysical properties with tunable electronic structure. This paper will give first an overview on the recent progress to produce stable and highly luminescent metal nanoclusters. In the second part, we will highlight the potential of such probes for bioimaging through in vitro /in vivo studies. © 1995-2012 IEEE.

Lajunen T.,University of Helsinki | Lajunen T.,Kyoto University | Viitala L.,Aalto University | Kontturi L.-S.,University of Helsinki | And 9 more authors.
Journal of Controlled Release | Year: 2015

Externally triggered drug release at defined targets allows site- and time-controlled drug treatment regimens. We have developed liposomal drug carriers with encapsulated gold nanoparticles for triggered drug release. Light energy is converted to heat in the gold nanoparticles and released to the lipid bilayers. Localized temperature increase renders liposomal bilayers to be leaky and triggers drug release. The aim of this study was to develop a drug releasing system capable of releasing its cargo to cell cytosol upon triggering with visible and near infrared light signals. The liposomes were formulated using either heat-sensitive or heat- and pH-sensitive lipid compositions with star or rod shaped gold nanoparticles. Encapsulated fluorescent probe, calcein, was released from the liposomes after exposure to the light. In addition, the pH-sensitive formulations showed a faster drug release in acidic conditions than in neutral conditions. The liposomes were internalized into human retinal pigment epithelial cells (ARPE-19) and human umbilical vein endothelial cells (HUVECs) and did not show any cellular toxicity. The light induced cytosolic delivery of calcein from the gold nanoparticle containing liposomes was shown, whereas no cytosolic release was seen without light induction or without gold nanoparticles in the liposomes. The light activated liposome formulations showed a controlled content release to the cellular cytosol at a specific location and time. Triggering with visual and near infrared light allows good tissue penetration and safety, and the pH-sensitive liposomes may enable selective drug release in the intracellular acidic compartments (endosomes, lysosomes). Thus, light activated liposomes with gold nanoparticles are an attractive option for time- and site-specific drug delivery into the target cells. © 2015 Elsevier B.V. All rights reserved.

Vida Y.,andalusian Center for Nanomedicine and Biotechnology | Vida Y.,University of Malaga | Perez-Inestrosa E.,andalusian Center for Nanomedicine and Biotechnology | Perez-Inestrosa E.,University of Malaga
Photochemical and Photobiological Sciences | Year: 2012

A new series of all-heterahomocalixarene-type structures was prepared. The new hetera[2 n]metacyclophanes obtained contain a benzophenone moiety as photoactive component. Although both forms possess identical building blocks and differ only in ring size, they are markedly different in photochemical reactivity. The cyclophane size is the driving force for the photochemical behaviour of the benzophenone. © The Royal Society of Chemistry and Owner Societies 2012.

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