Preclinical PET Neuroimaging of [ 11

Activation of retinoid X receptors (RXRs) has been proposed as a therapeutic mechanism for the treatment of neurodegeneration, including Alzheimer's and Parkinson's diseases. We previously reported radiolabeling of a Food and Drug Administration-approved RXR agonist, bexarotene, by copper-mediated [ 11 C]CO 2 fixation and preliminary positron emission tomography (PET) neuroimaging that demonstrated brain permeability in nonhuman primate with regional binding distribution consistent with RXRs. In this study, the brain uptake and saturability of [ 11 C]bexarotene were studied in rats and nonhuman primates by PET imaging under baseline and greater target occupancy conditions. [ 11 C]Bexarotene displays a high proportion of nonsaturable uptake in the brain and is unsuitable for RXR occupancy measurements in the central nervous system

PLGA encapsulation effect on Bioquin-HMPAO: radiolabeling and in vitro behaviour on brain and lung cancer cells

WOS: 000383579900016Bioquin-HMPAO (BH) was previously investigated as a novel brain imaging agent by in vivo biodistribution studies. Present studies are carried out to explore radiolabeling and in vitro behaviour evaluation of poly (lactic-co-glycolic acid) (PLGA) encapsulated BH nanocapsules (BH-PLGA NCs). BH-PLGA NCs were characterized utilizing dynamic light scattering and scanning electron microscope. Encapsulation effect on radiolabeling with Tc-99m was examined by stability and lipophilicity studies and effect on in vitro behaviour of Tc-99m-BH was evaluated by incorporation studies on DAOY, U87-MG and A549 cells. It is observed that PLGA encapsulation has a positive and reinforcement effect.Ege University Research FundEge University [2011 NBE 003]Current work is supported by Ege University Research Fund (contract no 2011 NBE 003). The authors thank to Cansu Uzaras and Cigdem Ichedef for the technical assistance during the assays