Carmen Waengler

Publications of Carmen Waengler

• Preparation of Water-Soluble Maleimide-Functionalized 3 nm Gold Nanoparticles: A New Bioconjugation Template.

  Authors: Jun Zhu, Carmen Waengler, R Bruce Lennox, Ralf Schirrmacher

  Langmuir : the ACS journal of surfaces and colloids. 03/2012; 28(13):5508-12.

  We present an efficient methodology to prepare maleimide-tethered, water-soluble gold nanoparticles (maleimide-AuNPs). The maleimide-AuNPs were prepared in the protected form and are readilyWe present an efficient methodology to prepare maleimide-tethered, water-soluble gold nanoparticles (maleimide-AuNPs). The maleimide-AuNPs were prepared in the protected form and are readily recovered via a retro-Diels-Alder reaction. The maleimide-AuNPs were fully characterized by (1)H NMR, TGA, TEM, and XPS and were determined to have a gold core with an average size of 3.2 ± 0.8 nm; each core contains about 1000 gold atoms and is surrounded by 30 maleimide-terminated ligands and 60 thiolated PEG ligands. The maleimide-AuNPs efficiently react with rhodamine 123 and cysteine and are a promising template for biological applications.

• Generation of novel single-chain antibodies by phage-display technology to direct imaging agents highly selective to pancreatic {beta}- or {alpha}-cells in vivo.

  Authors: Sandra Ueberberg, Juris J Meier, Carmen Waengler, Wolfgang Schechinger, Johannes W Dietrich, Andrea Tannapfel, Inge Schmitz, Ralf Schirrmacher, Manfred Köller, Harald H Klein, Stephan Schneider

  Diabetes. 08/2009;

  Objective: Non-invasive determination of pancreatic beta-cell mass in vivo has been hampered by the lack of suitable beta-cell specific imaging agents. This report outlines an approach for theObjective: Non-invasive determination of pancreatic beta-cell mass in vivo has been hampered by the lack of suitable beta-cell specific imaging agents. This report outlines an approach for the development of novel ligands homing selectively to islet-cells in vivo. Research Design and Methods: In order to generate agents specifically binding to pancreatic islets, a phage-library was screened for single-chain-antibodies (SCAs) on rat islets using two different approaches: (1) The library was injected into rats in vivo, and islets were isolated after a circulation time of 5 minutes. (2) Pancreatic islets were directly isolated, and the library was panned in the islets in vitro. Subsequently, the identified SCAs were extensively characterized in vitro and in vivo. Results: We report the generation of SCAs that bind highly selective to either beta- or alpha-cells. These SCAs are internalised by target cells, disappear rapidly from the vasculature and exert no toxicity in vivo. Specific binding to beta- or alpha-cells was detected in cell-lines in vitro, in rats in vivo, and in human tissue in situ. Electron microscopy demonstrated binding of SCAs to the endoplasmatic reticulum and the secretory granules. Finally, in a biodistribution study the labeling intensity derived from [(125)I]-labeled SCAs after i.v. administration in rats strongly predicted the beta-cell mass and was inversely related to the glucose excursions during an intraperitoneal glucose tolerance test. Conclusions: Our data provide strong evidence that the presented SCAs are highly specific for pancreatic beta-cells and enable imaging and quantification in vivo.