This trial aims to investigate the effectiveness of infusing donated pancreatic islet stem cells directly into the liver and pancreas of patients with type 1 diabetes. The trial is being conducted at the University of Chicago Medical Centre and proposes to enrol 10 patients with type I diabetes who are prone to severe hypoglycaemic events. All the participants will receive a transfusion of a preparation of donated islet stem cells directly into the hepatic venous system via the portal vein. Insulin production will be monitored for one year after the transfusion. The study is expected to be completed by June 2019.