Radiosynthesis and biological evaluation of the 99mTc-tricarbonyl moxifloxacin dithiocarbamate complex as a potential Staphylococcus aureus infection radiotracer

In the present investigation, radiosynthesis of the Tc-99m-tricarbonyl moxifloxacin dithiocarbamate complex (Tc-99m(CO)(3)-MXND) and its biological evaluation in male Wister rats (MWR) artificially infected with Staphylococcus aureus (S. aureus) was assessed. The Tc-99m(CO)(3)-MXND complex was radiochemically examined in terms of stability in saline and in serum and biologically its in-vitro binding with S. aureus and percent absorption in MWR models. Radiochemically the Tc-99m(CO)(3)-MXND complex showed more than 90% stability in saline up to 240 min and in serum 14.95% undesirable species was appeared within 16 h. In-vitro the Tc-99m(CO)(3)-MXND complex showed saturated binding with S. aureus. In MWR artificially infected with live S. aureus the complex showed about six fold higher uptakes in the infected muscle as compared to the normal muscle. However, insignificant change in the uptake of Tc-99m(CO)(3)-MXND complex in the infected and inflamed or normal muscle was observed in the MWR infected with heat killed S. aureus. The Tc-99m(CO)(3)-MXND complex disappeared from the circulatory system and appeared in the urinary system within 60-90 min followed by excretion through normal route of urinary system. Based on the elevated and stable radiochemical succumb in saline, serum, saturated in-vitro binding with S. aureus and higher accumulation in the target organ of the MWR, we recommend the Tc-99m(CO)(3)-MXND complex for radio-localization of the infection induced by S. aureus in human. (C) 2011 Elsevier Ltd. All rights reserved.