August 1995, I started designing the clinical promising islet purification solution of Iodixanal in UW-Solution (UWS). I mixed Optiprep – a 60 % solution of iodixanol in water – with a 2-times concentrated UWS, to prepare this density gradient solution. The first standard operation procedure of this Iodixanol-UWS gradient for our pig islet isolation research was completed November 1995.
This purification solution was a logical follow-up of our highly succesful Percoll-UWS density gradient — a similar solution of impermeants (that do not readily enter cells) with similar osmolarity (close to that of the tissue) , more practical though, and with the important advantage that iodixanol is clinical tested.
The Leiden Islet Lab had just moved into the Surgery Lab of the new LUMC building, and the islet team had grown, focussing on xenotransplantation. With more people isolating pig islets, more convenient solutions were tried.
Both Percoll-UWS and and the more convenient Histopaque-UWS were being used from 1992 for small scale islet isolations from juvenile pig pancreases.
July 1996, I introduced the Optiprep-UWS gradient to replace our Percoll-UWS gradient for larger scale porcine islet isolations , in comparison with the Histopaque gradient.
This work was first presented September 1997, both in this poster presented at the Xenotransplantation Congress in Nantes (France) and later that month also in a talk at the 6th Congress of the International Pancreas and Islet Transplant Association (IPITA) in Milan (Italy) — presentations that will be online at this site soon.
Notes
Van der Burg MPM, Basir I, Bouwman E. Non-traumatic porcine islet density gradient purification in a novel iodixanol in University of Wisconsin solution. The 4th Int. Congress for Xenotransplantation, Nantes (France) Sept. 7–11, 1997.
Update 20250128 – update intro design timeline
Citation info : Purification Islets in Iodixanol-UWS • Leiden Start 1996 • Michel van der Burg • Miracles.Media • @1MEMO 20250126 • URL michelvanderburg.com/2025/01/26/
