Radiosynthesis of (99m)Tc(CO)3-Clinafloxacin Dithiocarbamate and Its Biological Evaluation as a Potential Staphylococcus aureus Infection Radiotracer.

BACKGROUND

Clinafloxacin dithiocarbamate (CNND) was radiolabeled with technetium-99m ((99m)Tc) using (99m)Tc(CO)3(H2O)3 and assessed for its radiochemical stability in saline and serum, its in vitro binding with methicillin-resistant Staphylococcus aureus (MRSA) and biodistribution in female nude mice (FNM) artificially infected with live and heat-killed MRSA.

METHODS

In normal saline (NS) the (99m)Tc(CO)3-clinafloxacin dithiocarbamate ((99m)Tc(CO)3-CNND) showed radiochemical stability with a maximum value of 99.10 ± 0.20% and remained stable up to 4 h (92.65 ± 0.18%).

RESULTS

In human serum at 37°C within 16 h of incubation, 14.85% side products as a result of de-tagging developed. Incubation with MRSA gave saturated binding with a maximum value of 72.75 ± 1.20%. Almost six-fold higher uptake was seen in the infected muscle of the FNM as compared to the inflamed and normal muscle. The (99m)Tc(CO)3-CNND complex showed a normal route of excretion from the body of the FNM model.

CONCLUSION

The higher stability in NS, HS, saturated in vitro binding with a live strain of MRSA and six-fold higher uptake in the target organ showed the (99m)Tc(CO)3-CNND complex to be a potential MRSA infection radiotracer.