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DOI: 10.1055/s-0033-1346628
Environment sensing lipid based photo-accustic, MRI-optical tracer system validation in vitro and vivo models
Ziele: New nanoparticle and smart drug delivery agents are needed for imaging and theragnostic approaches. However there has been clear lack of probes that can be used simultaneously in molecular and organ level and that can bring light to the back ground accumulation to tumors (EPR) and active receptor mediated targeting.Here we describe a environment sensing multimodal photo-accustic MRI-optical tracer system that is promising due to a fact that they can give the anatomical information in tissue and organ level in animal models and in the same time give the precise information of the receptors and binding in cellular level. Methode: Liposome formulations
Lipids were purchased from Avanti Polar Lipids. Various thermo sensitive formulations were made by a lipid mixture consisting of a total of 20 uM of lipids DSPC/DMPC/chol/DOTAP. Liposomes were prepared as described in Medina OP et al. Lipids were allowed to hydrate in buffered water solutions containing either ICG or Alexa 680 streptavidin and 20 nm USPIO particles. After extrusion liposomes were purified from the unbound compounds by a PD 10 column and controlled by liposome size measurements by using dynamic light scattering.
Photo accustic phantoms and ex-vivo animal experiments were performed with Vevo LAZR apparattus. MRI phantom and ex-vivo experiments were made with Bruker 7 tesla MRI system. Ergebnis: Co-encapsulation of ICG and iron was relatively efficient to termosensitive and control liposomes. Best liposome formulations were long lived in storage conditions. Our probe gave good signal in MRI and photo acoustic phantoms. Surprisingly we were also able to visualize the ICG liposomes by using multiphoton microscopy. This might be due the fact that ICG has multiple peaks some being in the lower wave lengths. Liposome phase transition could be seen in the optical tracer by the change in optical properties. Schlussfolgerung: Activated multi modal probe could be used as an reporter in cellular, tissue and whole animal level imaging.
Korrespondierender Autor: Penate-Medina O
Christian-Albrechts-Universität zu Kiel, radiologie, Am Botanischen Garten 14, 24118 kiel
E-Mail: oula.penate@rad.uni-kiel.de
liposomes - teragnostic - drug delivery