Harnessing the Maltodextrin Transport Mechanism for Targeted Bacterial Imaging: Structural Requirements for Improved in vivo Stability in Tracer Design

• DOI: 10.1002/cmdc.201700543
• Publication Date: 2017-11-30T10:38:47Z
• Authors: Alexander Axer; Sven Hermann; Gerald Kehr; David Clases; Uwe Karst; Lena Fischer‐Riepe; Johannes Roth; Manfred Fobker; Michael Schäfers; Ryan Gilmour; Andreas Faust
• Keywords: Maltodextrin; TRACER; Emission computed tomography; Spect imaging; Metabolic stability

Abstract Diagnosis and localization of bacterial infections remains a significant clinical challenge. Harnessing bacteria‐specific metabolic pathways, such as the maltodextrin transport mechanism, may allow specific imaging small or hidden colonies. This requires that intrabacterial tracer accumulation provided by transporter is matched high serum stability molecule. Herein, radiolabeled maltodextrins varying chain lengths with free nonreducing/reducing ends are reported their behavior against starch‐degrading enzymes in blood, which compromise stability, evaluated. Successful single‐photon emission computed tomography (SPECT) shown footpad infection model vivo using newly developed tracer, [ 99m Tc] MB1143 , signal compared 18 F‐fluorodeoxyglucose positron ([ F]FDG‐PET) nonbacterial marker for inflammation. Although highly specific, it low, most probably due to insufficient tracer. A series tests different F‐labeled finally yielded clear structural guidelines regarding substitution patterns maltodextrin‐based tracers nuclear infections.