Abstract: A device is described which provides a totally enclosed and secure environment for the culture of cells and for the production of biologicals, pharmaceuticals, and other cell-derived products of commercial value. The device comprises several modules of differing functions: regulating the cellular growth environment, providing a suitable cell growth substrate or environment, or separating of desired product form interfering substances. Each module comprises a series of membranes separated by a solid support material which is channeled to provide a series of parallel capillaries for the flow of nutrients, environmental regulating fluids, or gas exchange. The structure and composition of the separating membranes limits the nature, rate, and size of the particular material exchanged across an individual membrane into or from an adjacent compartment. The capillaries are so dimensioned that the nutrients and gases are diffused over distances typical of human tissue.