Fig. 1.

Schematic view of the chamber system for islet macroencapsulation and encapsulated porcine islets. (A) The system is built from two islet compartments containing the islets immobilized in alginate and an oxygen module in center, connected to access ports for exogenous oxygen refilling. These ports allow direct injection of oxygen-enriched gas mixture (95% oxygen at 1.4 ATM; 1,011 Torr) into the central cavity. Oxygen is diffusing via the gas permeable membranes into two external chambers and via additional two gas permeable membranes into the cell chambers, where it is dissolved and consumed by the islets. According to mathematical models, refueling of oxygen every 24 h ensures minimal pO₂ within the islet module at above critical value of 60 Torr at all islets, (29). The plastic housing of the chamber is covered by porous membranes of hydrophylized polytetrafluoroethylene impregnated with alginate. Drawing is not to scale. (B) Microscopic image (brightfield) of porcine islets immobilized in alginate ready for integration into the chamber system.