In this project, flexible thin-film encapsulation devices were developed which incorporate an internal amino acid reservoir that provides nutrients to encapsulated cells, until the device has been vascularized. This technology has been shown to enhance cell engraftment and long term viability of encapsulated hESC-derived insulin producing cells.   Additionally, an external protein releasing reservoir was also incorporated into the device in order to provide immunomodulation post-transplantation. The release of key immunomodulators locally, in proximity to the encapsulation device, was shown to protect encapsulated cells from cytokine-induced destruction.   In vitro tests were performed to optimize cell survival and in vivo tests confirmed long term viability and functionality of encapsulated cells within these devices. Future studies are being conducted to confirm the long term ability of these nutrient releasing and immunomodulatory cell encapsulation devices to reverse diabetes.