Cell culture vessel

A cell culture vessel comprising:

• a wall comprising an inner surface defining a cell culture chamber of the vessel;
• a substrate positioned in the cell culture chamber between a first region of the cell culture chamber and a second region of the cell culture chamber, the substrate comprising a plurality of microcavities and a layer of porous material, each microcavity of the plurality of microcavities comprising a concave surface defining a well and an opening defining a path from the first region into the well, wherein a first side of the layer of porous material defines at least a portion of the concave surface of each microcavity of the plurality of microcavities, and wherein a second side of the layer of porous material faces the second region and further wherein the layer of porous material is permeable to gas and impermeable to liquid to allow gas exchange with the second region;
• and
• a first aperture extending through the wall in fluid communication with the first region.