The main focus of the PET-tracer developing group is put on the design of radiotracers with the most prominent short-lived positron emitters 18F-fluorine (t1/2 = 109.8 min) and 11C-carbon (t1/2 = 20.4 min) for imaging of parameters essential for tumor development as tumor growth, nutrition and expansion. PET-tracers for the recognition of tumor specific receptors and mapping of defined stages in tumor outgrowth as cell cycle, angiogenesis and metastasis are essential prerequisites for successful tumor therapy.Our actual research field covers the development of radiolabeled inhibitors of the Eph receptor, and of the enzymes cyclooxygenase 2 (COX-2) and cathepsin. New tracers are synthesized by procedures adapted from medicinal and pharmaceutical chemistry; the labeling reaction with [18F]fluoride is accomplished either by nucleophilic substitution or by means of special 18F-containing building blocks or prosthetic groups. 11C-Labeling is performed primarily by methylation reaction of a selected precursor with [11C]CH3I or [11C]CH3SO3CF3.
Methods / Equipment
- Performance of all fields of organic chemistry for synthesis of reference compounds and labeling precursors inclusive complete analytical characterization with NMR (VARIAN, Inova 400), ESI mass spectrometry (MICROMASS, Triple Quattro) and HPLC (MERCK-HITACHI, LaChrom, Elite).
- Synthesis of peptides with an automated microwave assisted Peptide Synthesizer (Liberty,CEM) using the Fmoc based protection strategy.
- Application of labeling reactions with [18F]fluoride by nucleophilic substitution in GBq scale on automated synthesizers (TRACERLabFXN, GE) including purification of products with semi-preparative HPLC.
- Performing of 11C-methylation reactions with [11C]methyl iodide and [11C]methyl triflate that are produced from [11C]methane by gas phase iodination in a commercial synthesizer (TracerlabFXCpro, GE) inclusive semi-preparative purification of the products
- Routinely production of N-succinimidyl-4-[18F]fluorobenzoate [18F]SFB on a house constructed automated synthesizer module and purification on solid phase in GBq scale as prosthetic group for the labeling of peptides with [18F]fluoride