title: Radiolabeling RGD peptide and preliminary biodistribution evaluation in mice bearing S180 tumors.
abstract: OBJECTIVE
  To prepare the rhenium-188 (188Re)-arginine-glycine-aspartic acid (RGD) peptide in a convenient manner and to evaluate its potential as an agent for alphavbeta3 integrin receptor-positive tumors.
  
  
  METHODS
  Radiolabeled RGD was obtained by conjugating the His group at the end of peptide with fac-[188Re(H2O)3(CO)3]+. Chelating efficiency of fac-[188Re(H2O)3(CO)3]+ and radiolabeling efficiency of radiolabeled peptide were measured by thin-layer chromatography and high-performance liquid chromatography. In-vitro stability of the radio-complex was determined in phosphate-buffered saline (0.05 mol/l, pH 7.4), new-born calf serum, His or Cys solution at 37 degrees C or room temperature and analyzed by thin-layer chromatography. A biodistribution study was carried out in mice bearing S180 tumors.
  
  
  RESULTS
  188Re-RGD was obtained with a more than 95% of radiolabeling efficiency, and showed high stability in phosphate-buffered saline, new-born calf serum, His and Cys solution. Furthermore, this radio-complex was cleared rapidly from the blood and showed specific tumor uptake in mice bearing S180 tumors.
  
  
  CONCLUSIONS
  188Re-RGD was prepared by a simple method. Preliminary biodistribution results showed its potential as an agent for cancer therapy and encouraged further investigation.
authors.affiliation: Shanghai Institute of Applied Physics (SINAP), Chinese Academy of Sciences, PR China.
authors.forename: Yufei
authors.initials: Y
authors.lastname: Ma
authors.forename: Junfeng
authors.initials: J
authors.lastname: Yu
authors.forename: Yanjiang
authors.initials: Y
authors.lastname: Han
authors.forename: Hua
authors.initials: H
authors.lastname: Shen
authors.forename: Zheng
authors.initials: Z
authors.lastname: Li
authors.forename: Wei
authors.initials: W
authors.lastname: Zhou
authors.forename: Duanzhi
authors.initials: D
authors.lastname: Yin
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D039302:Integrin alphaVbeta3 / Q000378:metabolism; D051379:Mice; D009369:Neoplasms / Q000188:drug therapy / Q000378:metabolism*; D009842:Oligopeptides / Q000737:chemistry* / Q000378:metabolism / Q000493:pharmacokinetics* / Q000627:therapeutic use; D055550:Protein Stability; D011868:Radioisotopes; D012211:Rhenium / Q000737:chemistry*; D014018:Tissue Distribution
chemical_list: D039302:Integrin alphaVbeta3; D009842:Oligopeptides; D011868:Radioisotopes; D012211:Rhenium; C047981:arginyl-glycyl-aspartic acid