Disclosed herein are various bioreactor devices and systems for growing cellular material, and related methods of growing cellular material. In some cases, a system can include a well plate having a plurality of wells and a bioreactor situated in each well of the well plate. In some cases, a bioreactor can include an inner body which divides the bioreactor into several distinct chambers and facilitates the growth of a multi-tissue sample in the bioreactor. In some cases, a system can include a mechanical actuator situated to mechanically stress tissues grown in a bioreactor.