Cancer care is increasingly personalized, because no two cancer patients are the same. This is a huge challenge for clinical care, especially for patients with rare cancers, because the standard of care don’t work for them. We envision solving this problem through personalized medicine, by testing drugs on many patient disease ‘avatars’ and identifying the right drug or drug combinations for the right patient. These avatars are made of fragments of patient biopsies cultured in “jelly-like” scaffolds. These artificial environments will be crucial to maintain tissues outside the patient’s body. Our goal in this grant is to find such scaffold designs that maximize the viability of the tissues ex vivo so that drug screening is feasible.