In this study the islets will be surface modified to carry immobilised heparin (Corline Heparin Conjugate) prior to transplantation. The primary objective is to investigate safety and efficacy of allogeneic islet transplantation using islets coated with immobilised heparin. The modification with heparin has been shown to protect the islets from being attacked by the immediate defence systems in blood (coagulation and inflammation), so that a larger portion of the islets will survive the initial phase and engraft. Evaluation will be based on metabolic and blood chemistry parameters.