PROJECT SUMMARY Most nanoparticles for drug delivery fail in clinical trials due to insufficiency of animal models, highlighting the need for additional models to support the development of new nanoparticles. Specifically, there are limited quantitative methods to aid in the systematic design and development of nanoparticles for drug delivery to cancerous tumors. The proposed computational models can predict drug delivery to tumors, and we demonstrate model accuracy in preliminary studies. The goal of this project is to develop computational models that can simulate drug delivery to tumors in 3-D, incorporating spatial heterogeneities in tumor properties. This is achieved by employing 3-D imaging studies to derive tumor parameter maps, and then integrating those maps in the computer model. If successful, the proposed computer models will enable systemic evaluation of nanoparticles not possible with other experimental methods and may result in more efficient nanoparticle- based cancer therapies.