title: Evolving role of radiolabeled particles in detecting infection and inflammation, preliminary data with 99mTc-phytate in rats.
abstract: OBJECTIVE
  The aim of this study was to evaluate the ability of phytate radiolabeled with technetium-99m (Tc-phytate) to identify inflammatory processes.
  
  
  METHODS
  Radiolabeling efficiency analyses were carried out by thin-layer chromatography on silica gel strips, yielding a radiochemical purity of 92%. In addition, the partition coefficient of Tc-phytate, obtained in a mixture of n-octanol/water (1 : 1), showed hydrophilic features of the radiopharmaceutical. After Tc-phytate was administered into the tail vein of healthy and inflammation focus-bearing rats, induced, in the right tight, by zymosan suspension at 5% (w/v), blood clearance evaluation was performed and showed a short plasma half-life (2.7 min). In the inflammation focus-bearing rats, Tc-phytate scintigraphic images were obtained at 2, 4, and 8 h after radiotracer injection.
  
  
  RESULTS
  A significant radiopharmaceutical uptake was found in mononuclear phagocyte system organs (liver and spleen) and in the inflammation focus (compared with contralateral muscle). Histopathological analysis showed an intense mononuclear infiltration in the inflamed muscle, suggesting that macrophages may be responsible for the greater radiotracer uptake in the inflamed site. Furthermore, the target-to-nontarget ratio (%ID/g of inflamed muscle-to-%ID/g of control muscle ratio) obtained by scintigraphic images performed at 2 h after the radiotracer injection was 10.24±3.49, remaining without any significant difference at 4 and 8 h.
  
  
  CONCLUSIONS
  Inflammation focus was evident in the scintigraphic images from 2 to 8 h after Tc-phytate administration, suggesting that this radiopharmaceutical could be a potential alternative to identify inflamed regions.
authors: aDepartment of Medicine bDepartment of Pharmacy cDepartment of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil dDepartment of Radiology, Division of Nuclear Medicine, Stanford University, Stanford, California eDepartment of Radiology, Division of Nuclear Medicine and Clinical Molecular Imaging, Hospital of the University of Pennsylvania, Perelman School of Medicine, Philadelphia, Pennsylvania, USA fDepartment of Nuclear Medicine and Molecular Imaging, Santa Maria della Misericordia Hospital, Rovigo, Italy.
authors: Luciene G
authors: LG
authors: Mota
authors: André L B
authors: AL
authors: de Barros
authors: Leonardo L
authors: LL
authors: Fuscaldi
authors: Cristina M
authors: CM
authors: de Souza
authors: Geovanni D
authors: GD
authors: Cassali
authors: Mateen
authors: M
authors: Moghbel
authors: Abass
authors: A
authors: Alavi
authors: Domenico
authors: D
authors: Rubello
authors: Simone O A
authors: SO
authors: Fernandes
authors: Mônica C
authors: MC
authors: Oliveira
authors: Valbert N
authors: VN
authors: Cardoso
mesh_terms: D000818:Animals; D057927:Hydrophobic and Hydrophilic Interactions; D007239:Infections / Q000000981:diagnostic imaging*; D007249:Inflammation / Q000000981:diagnostic imaging; D007553:Isotope Labeling; D008297:Male; D000442:Octanols / Q000737:chemistry; D010833:Phytic Acid / Q000737:chemistry*; D011854:Radiochemistry; D011877:Radionuclide Imaging; D051381:Rats; D017208:Rats, Wistar; D013667:Technetium / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D000442:Octanols; D014867:Water; D013667:Technetium; D010833:Phytic Acid