Concentration of cisplatin-incorporated polymeric micelles in a murine solid tumor evaluated using PIXE analysis

We report an elemental analysis of murine solid tumors treated with cisplatin-incorporated polymeric micelles (NC-6004) to evaluate the concentration of the drug in the tumor tissue using conventional particle-induced X-ray emission (PIXE) analysis, as well as the spatial distribution in the tumor section using sub-millimeter PIXE analysis. The results reveal that the platinum concentration in the tumor treated with NC-6004 was higher than in that treated with cisplatin, whereas no significant difference was found in platinum concentration between NC-6004 and cisplatin samples in the normal tissue. This suggests that NC-6004 can both provide therapeutic efficacy and reduce the side effects caused by conventional treatment using cisplatin. These results show that PIXE analysis is a powerful tool for research into drug delivery systems.