Pretransplant culture selects for high-quality porcine islets.

Objectives: The pig is generally considered a suitable alternative donor for clinical islet transplantation. However, adult pig islets are difficult to isolate and culture, often behave variably in in vitro assays, and do not consistently cure diabetic nude mice. In this study, we compared the in vivo function of freshly isolated and cultured adult porcine islets by transplantation in diabetic nude mice.

Iodixanol density gradient preparation in university of wisconsin solution for porcine islet purification.

Generally, prior to the purification of isolated pancreatic islets, the collagenase-digested tissue is incubated in the University of Wisconsin solution (UWS; approximately 320 mOsm) for osmotic stabilization to preserve or improve the density differences between islets and acinar fragments. The adverse effects arising from the subsequent pelleting and resuspension of the islets in a second, different (often highly hyperosmotic) purification solution are avoided in the protocol described here; preparation of the purification medium is simply achieved by mixing the UWS preincubated islets with a second UWS containing the inert impermeant iodixanol. Flotation of the islets isolated from juvenile porcine pancreases through this mildly hypertonic (approximately 380 mOsm) gradient of iodixanol-UWS achieves a much higher recovery of islets of an improved viability than the customary method using a Ficoll gradient.