Islet Distribution in Decellularized Liver Bioscaffolds by Infusion Through the Portal Vein

Objective. To investigate the position and the circumstance of islet transplantation in the blood vessels of the liver, we infused DTZ-stained islets through the portal vein into decellularized liver bioscaffolds of C57BL/6 mice or SD rats. Methods. The livers were decellularized by perfusion with a sodium dodecyl sulfate detergent solution from the portal vein in vivo to prepare the decellularized liver bioscaffold. Then, the DTZ stained islets were infused through the portal vein into the bioscaffold. The positions and the conditions permitting embolism by islets in the liver microvascular system were investigated by examining the inside of the decellularized liver bioscaffold with a stereo microscope and an inverted microscope. Results. After the decellularization, a clear and transparent liver bioscaffold was present with rich vascular branches in the liver. After the infusion of 300 +/- 50 IEQ of mouse islets, 800 +/- 250 IEQ of rat islets, or 800 +/- 250 IEQ of human islet tissues, the majority of islets were embolized in the edges of the peripheral microvascular system of the mouse and rat liver bioscaffolds. Some branches were even embolized by more than one islet. For human islet transplantation, exocrine tissues and islets were observed to co-exist in the same microvascular branch, which might accelerate the depletion of nutrition and oxygen supply to the islets, leading to their dysfunction. Conclusions. This paper clearly presents the microvascular network of the liver and the distribution of islets in the liver, which were infused into the liver from the portal vein. These results create a solid foundation for further studies on how to improve the survival and the function of islets transplanted in the liver.