Complement Permeability in Bio-Artificial Endocrine Pancreas Using a Diffusion Chamber

Immunoisolation is a potentially important approach to transplanting islets without any immunosuppressive therapy. This study was designed to investigate whether complement penetrates into the diffusion chamber that we developed for a bioartificial endocrine pancreas (Bio-AEP). The results showed that within 12–24 h, when a Nuclepore membrane (Nuclepore Corp., California) was the sole barrier, complement permeated 100%. However, the Nuclepore membrane used together with a mixed matrix prevented complement penetration. Also, the complement become inactivated during penetration through both the mixed matrix and the Nuclepore membrane with a pore size of 0.1 μm. In conclusion, immunoisolation of cells by a mixed matrix and a Nuclepore membrane of 0.1 μm pore size is a particularly effective method for transplanting xenogeneic cells. Thus, the clinical application of our Bio-AEP shows promise for long-term xenotransplantation without an immunosuppressant.