Self-assembly of hybrid 3D cultures by integrating living and synthetic cells

Abstract Self-assembly, a fundamental property of living matter, drives the interconnected cellular organization of tissues. Synthetic cell models have been developed as bionic materials to mimic inherent cellular features such as self-assembly. Here, we leverage co-assembly of synthetic and natural cells to create hybrid living 3D cancer cultures. We screened synthetic cell models, including giant unilamellar vesicles, coacervates, microdroplet emulsions, proteinosomes, and colloidosomes, for their ability to form hybrid tumoroids. Our results identify the balance of inter- and extracellular adhesion and synthetic cell surface tension as key material properties driving successful co-assembly of hybrids. We further demonstrate that these synthetic cells can establish artificial tumor immune microenvironments (ART-TIMEs), mimicking immunogenic signals within tumoroids. Using the ART-TIME approach, we identify co-signaling mechanisms between PD-1 and CD2 as a driver in immune evasion of pancreatic ductal adenocarcinoma. Our findings demonstrate the 3D bottom-up self-assembly of hybrid cancer microenvironments to replace immune components with defined bionic materials, pushing the boundaries to functionally integrating living and non-living matter.