Radiosynthesis and biodistribution of the 99mTc-trovafloxacin complex as a potential methicillin resistant Staphylococcus aureus infection radiotracer

Abstract

In the current investigation radiosynthesis of the 99mTc-trovafloxacin (99mTc-TVN) complex and its biodistribution in male Wistar rats (MWR) artificially infected with live and heat killed methicillin resistant Staphylococcus aureus (MRSA) was studied. Further the complex was evaluated in terms of the radiochemical stability in normal saline, in vitro stability in serum and in vitro binding with MRSA. The complex showed radiochemical purity (RCP) in normal saline with a maximum value of 97.30 ± 0.52% at 30 min after its reconstitution. The RCP value went down to 90.45 ± 0.48% within 4 h. In serum at 37 °C, the complex showed permanence up to 4 h but within 16 h of incubation the production of undesirable side product of 17.25% (free and radio-colloid) was observed. In buffer the labeled TVN showed saturated in vitro binding with live MRSA. The uptake of the complex in the thigh of the MWR infected with live MRSA was almost five fold than those infected with heat killed MRSA. The high RCP values, in vitro stability in serum, saturated in vitro binding with MRSA and promising biodistribution with six fold higher accumulation in the infected organ of the MWR infected with live MRSA established the usefulness of the 99mTc-TVN as a promising MRSA infection radiotracer.