Inhibition of instant blood-mediated inflammatory responses by co-immobilization of sCR1 and heparin on islets.

Intraportal transplantation of islets of Langerhans is followed by marked islet loss, mainly caused by instant blood-mediated inflammatory responses (IBMIR). We previously developed a method of co-immobilizing sCR1 and heparin on islets. Here we examined whether this process could reduce islet loss following intraportal islet transplantation in a syngeneic mouse model.

Xenotransplantation of islets enclosed in agarose microcapsule carrying soluble complement receptor 1.

Strong immunological reactions remain a major barrier to treating diabetic patients using xenogeneic islets. In a previous study, we developed a method for enclosing islets with agarose microbeads carrying soluble complement receptor 1 (sCR1-Mics), a potent complement inhibitor in both classical and alternative complement activation pathways. This is the follow-up in vivo study to evaluate the protective effect of these sCR1-Mics using a xenotransplantation model (rats to mice).

Layer-by-layer co-immobilization of soluble complement receptor 1 and heparin on islets.

Early graft loss due to instant blood-mediated inflammatory reactions (IBMIRs) is a major obstacle of clinical islet transplantation; inhibition of blood coagulation and complement activation is necessary to inhibit IBMIRs. Here, human soluble form complement receptor 1 (sCR1) and heparin were co-immobilized onto the surfaces of islet cells. sCR1 molecules carrying thiol groups were immobilized through maleimide-poly(ethylene glycol)-phospholipids anchored in the lipid bilayers of islet cells.

Immobilization of the soluble domain of human complement receptor 1 on agarose-encapsulated islets for the prevention of complement activation.

The transplantation of islets of Langerhans has been successfully applied to the treatment of insulin-dependent diabetes. However, a shortage of human donors is the hardest obstacle to overcome. We aimed to develop a bioartificial pancreas that can realize xeno-islet transplantation.

Microencapsulation of islets with living cells using polyDNA-PEG-lipid conjugate.

Microencapsulation of islets with a semipermeable membrane, i.e., bioartificial pancreas, is a promising way to transplant islets without the need for immunosuppressive therapy for insulin-dependent diabetes mellitus (type I diabetes).