This research involves demonstrating the viability of filling the nanotubes with copper and characterizing its effectiveness as a vehicle for transport of radionuclide. A two-step filling method has been adopted in this study. First, the multi-walled carbon nanotubes (MWCNTs) closed ends were opened by acid reflux; then, using the capillary effect, the tubes were filled with copper by sonicating them in a copper salt solution. The effects of changing the reflux time, changing the molar concentration and replacing the copper nitrate salt with copper chloride have been studied. The success of this process has been tested using scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDS), x-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Using a 12 hour reflux time in 68% HNO3 resulted in opening of the MWCNTs which in turn allowed filling them with copper. The filling took place by sonicating the opened MWCNTs in 0.87 mol/L Cu(NO3)2 solution. Subsequent characterization by EDS and XPS show the presence of copper in the MWCNTs. Variations in reflux time and copper molar concentration were observed to change the copper concentration. TEM images show that the Cu nanoparticles are located inside the nanotubes. Multi-walled carbon nanotubes were reproducibly filled with copper using a Cu(NO3)2 solution. Altering the reflux time and the copper molar concentration were shown to affect the subsequent copper concentrations in the MWCNTs. These data form a proof of concept supporting the ability to use MWCNTs filled with copper for targeted radiotherapy.