Implantable gas delivery device and methods, systems, and devices including same. According to one embodiment, the implantable gas delivery device includes a porous core that permits facile transport of gas throughout its open volume. The porous core has sufficiently high tensile strength to withstand pressurization without significant deformation. The porous core is generally planar and is shaped to include a pair of opposing surfaces and a periphery. Diffusion membranes are fixed to the two opposing surfaces of the porous core. A gas supply tube has one end inserted into the porous core and another end connectable to a gas source. The periphery of the porous core is sealed gas-tight, either with a gasket or by sealing the porous core and/or diffusion membranes. The device may be used to deliver a gas to an implanted cell capsule or to native cells or tissues or may be used to expel waste gas.
