Tirapazamine-loaded CalliSpheres microspheres: Preparation and characterization as a chemoembolization agent for liver cancer

Tirapazamine (TPZ), a hypoxia-selective cytotoxic agent, has proved to exert synergistic tumor-killing activity with transcatheter arterial embolization (TAE) against liver cancer. This advances TPZ to transcatheter therapies for liver cancer, particularly in combination with drug-eluting microspheres. We describe methods for preparing and characterizing TPZ-loaded CalliSpheres microspheres (CSMTPZs) with regard to their properties as a chemoembolization agent, which includes 1) preparation of CSMTPZs and determination of drug loading level, 2) in vitro determination of TPZ release, 3) assessment of CSMTPZ size and appearance, and 4) determination of TPZ pharmacokinetics and intratumoral drug concentration in vivo. These methods can be adapted for further clinical I trial. • This is to our knowledge the first methods for preparing and characterizing tirapazamine-loaded microspheres with regard to their properties as a chemoembolization agent; • Detailed protocols for preparation of CSMTPZs, determination of drug loading level, in vitro determination of TPZ release, assessment of CSMTPZ size and appearance, and in vivo determination of TPZ pharmacokinetics and intratumoral drug concentration; • Adaptable to experiments on other animal models and clinical trials.