Radio-sensitizing nanoparticles are a potential method to increase the damage caused to
cancerous cells during the course of radiotherapy. The distribution of these particles in a given targeted tumour is a relevant factor in determining the efficacy of nanoparticle enhanced treatment. In
this study a three-part mathematical model is shown to predict the distribution of nanoparticles
after direct injection into a tumour. In contrast with previous studies, here a higher value of diffusivity for charged particles was used and the concentration profile of deposited particles was studied. Simulation results for particle concentrations both in the interstitial fluid and deposited onto
cells are compared for different values of particle surface charges during and after injection. Our
results show that particles with a negative surface charge can spread farther from the injection location as compared to uncharged particles with charged particles occupying 100% of the tumour
volume compared to 8.8% for uncharged particles. This has implications for the future development
of radiosensitizers and associated trials.