A system has been constructed that recapitulate the features of a capillary bed through normal human tissue. The system facilitates perfusion of three-dimensional (3D) cell monocultures and heterotypic cell co-cultures at the length scale of the capillary bed. A major feature is that the system can be utilized within a “multiwell plate” format amenable to high-throughput assays compatible with the type of robotics commonly used in pharmaceutical development. The system provides a means to conduct assays for toxicology and metabolism and as a model for human diseases such as hepatic diseases, including hepatitis, exposure-related pathologies, and cancer. Cancer applications include primary liver cancer as well as metastases. The system can also be used as a means of testing gene therapy approaches for treating disease and inborn genetic defects.