Systems and methods for the dynamic co-culturing of two cell populations are provided. The system includes a barrier configured to physically separate a stimulator cell population from a responder cell population disposed within a container. The barrier is permeable to the secreted factors of at least one of the cell populations. The responder cell population can thereby be altered by exposure to the secreted factors to produce a population of reprogrammed cells that includes biomolecules (e.g., nucleic acids) originating from the stimulator cell population and/or that exhibits one or more additional or modified functional activities than a parental population of the reprogrammed cells.