The
imaging of the biodistribution and pharmacokinetics is critical
in understanding the complexity of drug delivery mechanisms, the status
of the disease, and the monitoring of the treatment progress. The
imaging techniques, such as magnetic resonance imaging, computed tomography,
and positron emission tomography, are suitable for clinical applications.
However, with regards to the biodistribution and pharmacokinetics,
their availability is often limited due to the requirements of ionizing
radiation or high magnetic fields, low spatial and temporal resolution
(applicable for animals), and high maintenance costs. Electron paramagnetic
resonance (EPR) imaging is a technique that allows for the minimal
invasive mapping of unique parameters, such as the oxygen concentration,
the redox state, the thiol concentration, or the pH level, in vivo. In this work, a high temporal resolution 3D EPR
imaging technique was used for assessing the trityl spin probe pharmacokinetics
in mice. The results demonstrate the preliminary outcomes in the application
of EPR imaging for the comparison of the trityl spin probe pharmacokinetics
between that of a healthy mouse and a tumor-bearing mouse. This study
will stimulate further investigation into the use of imaging strategies,
such as EPR imaging, to analyze pharmacokinetics.