Abstract: Provided herein are completely defined culture conditions, including culture supplements and requirements for an extracellular matrix, for facilitating the expansion of primary human hepatocytes.

Abstract: Featured is a device for aggregating populations of cells that includes one or more plates that include a microwell film composite. The microwell film composite includes a first layer with a plurality of microwells and a second layer that includes a permeable body that includes a plurality of pores. The device further includes one or more ports for fluid input and/or output. Also featured are methods of making aggregates including a first population of cells (e.g., parenchymal cells (e.g., hepatocytes)) and a second population of cells (e.g., stromal cells).