This invention provides an apparatus for growing cells under static or dynamic physiological pressure which contains a cell culture cassette having a cassette frame; two side walls secured to each side of the cassette frame to form a cell growing chamber, and at least one side wall comprises a cell growth surface. The apparatus also contains a means for adjusting fluid pressure or flow, for providing culture media or cell culture, or for sampling cell culture or culture media within the cell growing chamber. The apparatus further contains an adapter which contains two side assemblies where each side assembly includes a frame with a rigid support that fits over the cell culture cassette. The side assemblies joined by a hinge at one end and positioned over the two side walls of the cell culture cassette. The apparatus further contains a means to secure the two side assemblies over the two side walls of the cell culture cassette.