Method of delivering oxygen to cells by electrolyzing water

Oxygen is supplied to cells in vitro or in vivo by generating oxygen with an oxygen generator that electrolyzes water to oxygen and hydrogen. Oxygen can be generated substantially without generating free hydrogen using a multilayer electrolyzer sheet having a proton exchange membrane sandwiched by an anode layer and a cathode layer. The oxygen generator may be used to supply oxygen to cells contained by a culture plate, a culture flask, a microtiter plate or an extracorporeal circuit, or to cells in an encapsulating chamber for implanting in the body such as an immunoisolation chamber bounded by a semipermeable barrier layer that allows selected components to enter and leave the chamber. A bioactive molecule may be present with the cells. Oxygen can be delivered in situ to cells within the body such as by implanting the oxygen generator in proximity to cell-containing microcapsules in an intraperitoneal space, or by implanting a system containing the oxygen generator in proximity to an immunoisolation chamber containing cells.