One hundred fifty million people suffer from diabetes mellitus worldwide. Modern exogenous insulin therapy cannot prevent late complications. Islet cell transplantation could be a sufficient therapeutic option but the shortage of human organs limits this option. The use of xenogeneic porcine islet cells may also be a viable alternative. One way to manage hyperacute rejection is by the protection of xenogeneic cells from the immune system by microencapsulation. In this study sodium cellulose sulfate (NaCS) was evaluated as a material for encapsulation. An insulin-producing cell line (HIT-T15) was established in our laboratory. Glucose-dependent insulin production and cell growth were monitored. Cells were encapsulated with NaCS by Austrianova, Vienna. The insulin production and mitosis rate were examined. Cell growth and insulin production by HIT-T15 cells affected the glucose levels in the nutrient solution. Cell viability and glucose-dependent insulin production were not influenced by NaCS. Encapsulation with NaCS is feasible and it could be shown that the material is permeable to nutrients and metabolic side products. The encapsulated cells are able to detect the glucose concentration in the nutrient solution and to react in a proper way by producing insulin. Encapsulation with NaCS, which is more biocompatible and less immunogenic than other materials, seems to be a promising method for immunoisolation of porcine beta cells for xenotransplantation to replace the endocrine pancreas in a physiologic way.