Study on biological distribution of polyhexamethylene guanidine (PHMG), a toxic household chemical, using radiolabeling and molecular imaging tools

Abstract

A lot of people in Korea have suffered from severe toxicity of PHMG, a humidifier disinfectant. To assess the risk and in-depth mechanistic understanding of toxicity posed by a hazardous substance, it is essential to determine its biological uptake in organs. In this study, we investigate the biodistribution of PHMG using radioanalytical techniques. By labeling PHMG with radioactive indium (111In), the uptake values of PHMG in organs can be measured after intravenous injection in Sprague–Dawley rats for up to 168 h. The results indicate that PHMG is distributed in the liver (28.63% injected dose (%ID)) and lungs (12.44%ID) at 30 min post administration. In addition, the clearance rate of PHMG distributed in the internal organs is slow, with approximately 65% of injected PHMG remaining in the lungs after 1 week. Moreover, we quantified biodistribution of the radiolabeled PHMG exposed through intratracheal instillation and oral administration routes, and the observed data were compared to each other to understand in vivo behavior of PHMG. In addition, radiolabeled PHMG in an animal model can be visualized using SPECT/CT. The obtained results indicate that repetitive exposure to PHMG results in damage to lungs, as well as extrapulmonary organs.