Primate Islet Isolation and Purification in Iodixanol-UWS • @1MEMO_20260425
by Michel van der Burg, April 25th, 2026

In early 1999, ahead of the official launch of the clinical islet transplantation program at Leiden University Medical Center (LUMC), the author conducted a pilot study to assess whether a novel islet purification method could be applied to non-human primates.

The method combined Iodixanol (Optiprep/Visipaque) with University of Wisconsin Solution (UWS) — a preservation fluid used for donor organ storage. This Iodixanol-UWS approach had proven effective for purifying pig islets since 1996, and had been trialed on human donor islets during a 1998 visit to the Diabetes Research Institute (DRI) in Miami.

Islets were isolated from four non-human primates — one cynomolgus and three rhesus macaques — whose pancreases were procured during euthanasia of animals used in unrelated studies at the Biomedical Primate Research Centre in Holland.

Islets were purified by centrifugation in the Iodixanol-UWS gradient.

Results were excellent: an average yield of 3,697 islets / gram pancreas before purification, with 94% purity and 90% recovery after purification. Viability assessments , and a 98% culture survival confirmed high islet quality.

Colleague Krista Haanstra conducted immunogenicity analyses using a Mixed Lymphocyte Islet Culture (MLIC) assay.

Biosafety protocols for non-human primate tissue proved valuable preparation for the subsequent launch of human islet isolations at LUMC later that month.

Read the full report at michelvanderburg.com/2026/04/25/

#islets #Langerhans #isolation #purification #LUMC #Leiden #primate #macaque #optiprep #iodixanol #UWS #pancreas #transplantation #diabetes #history #research #1memo #michelvanderburg

Citation: Primate Islet Isolation and Purification in Iodixanol-UWS • @1MEMO_20260425 • Michel van der Burg • Miracles.Media • michelvanderburg.com/2026/04/25/

Successful Islet Transplantation After Purification in Iodixanol-UWS • IPITA 1999 Sydney • @1MEMO 20260326

Our studies demonstrated the importance of selection of : 1) the non-toxic islet isolation media iodixanol and UWS , and 2) islets that survive culture, for successful transplantation.

Pig islets after isolation in Iodixanol-UWS • 7th IPITA World Congress 1999 • 1MEMO_20260326_1 • Michel van der Burg • Miracles•Media • TakeNode 467e773c-fc4b-416e-99d5-c88df76ddff4

Josephine Rijkelijkhuizen at the 7th IPITA World Congress 1999 • 1MEMO_20260326_4 • Photo by Michel van der Burg • Miracles•Media • TakeNode 0c2ef6fb-bdff-4895-9dde-eb242f957cb9


Top 10 Paper

Our study — presented by our student researcher Josephine Rijkelijkhuizen —showing that cultured pig islets, isolated and purified in Iodixanol-UWS, can be transplanted without hyperacute rejection in cynomolgous monkeys , was selected in the top 10 outstanding studies at the memorable Sidney World Congress of the International Pancreas & Islet Transplant Association and the full paper included in a special issue of the journal Cell Transplantation .

Sydney Convention Center • 1MEMO_20260326_9 • Michel van der Burg • Miracles.Media • TakeNode 1ce6bbf2-adf1-4ce3-8c69-cd2d1339be81 • Sydney Convention Center - Darling Harbour (demolished in 2013)

youtube https://youtu.be/-p5lCyGr5Rs

FULL REPORT @ michelvanderburg•com
https://michelvanderburg.com/2026/03/26/


#IPITA #Sydney #surgery #laboratory #purification #optiprep #iodixanol #density #gradient #UWS #pancreas #human #pig #rat #mouse #monkey #xeno #islets #islet #Langerhans #isolation #UW #university #Wisconsin #transplantation #diabetes #man #history #Holland #Netherlands #Leiden #hospital #LUMC #1memo #michelvanderburg #Rijkelijkhuizen #Ricordi

Citation info : Successful Islet Transplantation After Purification in Iodixanol-UWS • IPITA 1999 Sydney • @1MEMO 20260326 • Michel van der Burg • Miracles.Media • URL michelvanderburg.com/2026/03/26/

New Powerful Tool For Human Islet Purification • OptiPrep-UWS ? • IPITA 1999 Sydney • @1MEMO 20260325

Poster (#P298) Michel van der Burg, 7th World Congress of the International Pancreas & Islet Transplant Association, Sydney (Australia) August 22–25, 1999 . 1MEMO_20260325_1 TakeNode 770715b8-ca68-4c00-8a24-24fe0d216c10

Outcome of the first series of human islet purifications with the novel Iodixanol -UWS density gradient — developed originally in the difficult model of pig islet isolation in our Leiden Islet Laboratory of the LUMC (2) — and, performed in 1998 during my working visit at the “fast track” center of the Diabetes Research Institute (Scientific director Prof. C. Ricordi, MD) of the University of Miami , in Miami, Florida, USA .

Notes

Abstracts of previous IPITA meetings had been published in print in scientific journals , however, at the turn of the millennium in 1999, with the rise of the internet , the 7th IPITA congress abstracts were published online only at the official website of the IPITA, in Oxford at the time (www.jr2.ox.ac.uk/ipita), and cannot be retrieved now.
I kept an archive with photocopies of our abstracts published in print in the Abstract Book of the 7th IPITA. Here that abstract of poster presentation P298 at page 169 in the Programme and Abstract Book.

7th IPITA World Congress 1999 • 1MEMO_20260325_2 • Michel van der Burg • Miracles•Media • TakeNode 9a8affeb-120a-4484-a390-fe058ac64af4


#IPITA #Sydney #surgery #DRI #Miami #clinical #laboratory #purification #optiprep #iodixanol #density #gradient #UWS #pancreas #human #pig #rat #mouse #monkey #xeno #islets #islet #Langerhans #isolation #UW #university #Wisconsin #transplantation #diabetes #man #history #Holland #Netherlands #Leiden #hospital #LUMC #1memo #michelvanderburg

Citation info : New Powerful Tool For Human Islet Purification • OptiPrep-UWS ? • IPITA 1999 Sydney • @1MEMO 20260325 • Michel van der Burg • Miracles.Media • URL michelvanderburg.com/2026/03/25/

25 Year Islet Transplants • @1MEMO_20140703 • 

17:35 - Michel enters with transplant.

17:50 - Vygon 6 cannulation

17:52 - 12 mg Heparin IV

17:57 - Transplant

18:00 - 2nd transplant
Activated Clotting Time (ACT) 362"

18:05 - Clamps removed

25 Year Islet Transplants • @1MEMO_20140703 • Michel van der Burg • Miracles•Media • TakeNode c28e9c36-22bc-4409-b26a-2f9f90d9d39b •

July 3, 2014 - Holland, Leiden University Hospital, 25 years ago : Photocopy June 13, 1989 surgery journal highlighting the moment of islet transplantion at our start of a first series of succesfull islets graft transplants in the Netherlands, using a simple yet very novel approach that eventually, recently, became a worldwide standard for transplanting clinical grade purified islets in insulin-dependent diabetic patients.
Link to article on the 25 year timeline of progress in research and patient treatment , here : https://www.cellr4.org/article/128 .

Notes

Update 20260319_0943 : adding english translation dutch surgery journal (as quote), and minor text modifications, as part of the process of republishing this post at michelvanderburg.com as part of the science portfolio dd 20260319 https://michelvanderburg.com/category/science/ from the original post at 1-memo•com: 25 Year Islet Transplants | 20140703 | 1-memo.com • URL https://1-memo.com/2014/07/03/25-year-islet-transplants/

#islet #transplantation #diabetes #LUMC #Leiden #history #AZL #UWS #purification #premiere