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

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 • Presentation by Michel van der Burg (Notes #5).

Shortly after our introduction at the previous IPITA World Congress, September 1997 in Milan (Italy) of the novel Iodixanol -UWS solution for isolation of juvenile pig islets (1), we reported successful xeno-transplantation in diabetic Swiss nude (immunodeficient) mice of adult pig islets isolated with this Iodixanol -UWS method, first Tuesday, Jan 27, 1998 at the 17th Workshop of the AIDSPIT Study Group in Igls, Austria (2a), and next April 1998 at the 10th Congress of the Dutch Transplantation Society (2b). We had started these first pig islet xenotransplants in mice also that same month of September 1997 — highlighted in the image below ( 1MEMO_20260326_12 )

First pig islet xeno transplants in mice • 1MEMO_20260326_12 • Michel van der Burg • Miracles•Media • TakeNode d4cc1f11-c107-4011-8dbe-9649da76e3ff • September 1997, we performed our first two pig islet xenotransplants into diabetic Swiss nude mice. The pig islets were isolated with Iodixanol-UWS from an adult pig pancreas (top panel: sample of the islets stained red with dithizone, fresh after isolation and purification). These pure islets were kept 1 week in a culture solution, before transplantation of the islets by injecting the islets under the kidney capsule in 2 diabetic Swiss nude mice. Both mice had normal blood glucose from the day one after transplantation, and upon removal of the kidneys for examination at 1 month after transplantation , we observed excellent islets under the kidney capsule , as shown in the bottom panel image of a kidney section stained with H&E (note : the inserted portrait of the Swiss nude mouse, actually is our #7 pig islet xenograft, alive and kicking, Dec 1997).

Starting with the September 1997 IPITA meeting in Milan, I was sharing in detail the materials and methods of our purification procedure, face to face and in post-congress correspondence, with my colleagues of the other islets centers, thus facilitating fast implementation by Bernhard Hering and Shinichi Matsumoto of the Iodixanol-UWS purification method in the Minneapolis islet center, contributing to their successful single-donor pig islet allo-transplants, as reported by Shinichi Matsumoto May 1998 at the 24th Annual Scientific Meeting of the American Society of Transplant Surgeons, in Chicago (3).

That month, May 1998, I also finished the first series of human islet purifications with the novel Iodixanol-UWS density gradient, while working on human islet isolations in the Miami team at the Diabetes Research Institute (Scientific director Prof. C. Ricordi, MD) of the University of Miami , in Miami, Florida, USA . The successful outcome of the human islet purification work done in Miami was reported from January 1999 in a talk and poster presentations , including a poster presentation at the 7th World Congress of the International Pancreas & Islet Transplant Association, Sydney (Australia) August 1999 (4).

Viability of Fresh vs Cultured Pig Islets for Transplants • 1MEMO_20260326_2

Slideshow presentation by Josephine Rijkelijkhuizen • 7th IPITA World Congress 1999 • Viability of Fresh vs Cultured Pig Islets for Transplants • 1MEMO_20260326_2 • Michel van der Burg • Miracles•Media • TakeNode 7164b724-65bf-4d3f-8a40-89b188957d1b • Notes #6

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Handout • PDF (Viability of Fresh vs Cultured Pig Islets for Transplants)
7th IPITA World Congress 1999 • 1MEMO_20260326_3 • Michel van der Burg • Miracles•Media • TakeNode 995e90b3-d797-435c-a510-00a0e35bc424 • Handout presentation by Josephine Rijkelijkhuizen (Notes #6).

In our oral presentations at the 7th World Congress of the International Pancreas & Islet Transplant Association, Sydney (Australia) August 1999, we demonstrated both the complete recovery of pure intact pig islets during isolation in UWS and purification in the novel solution of Iodixanol (Optiprep) in UWS, and the superior viability of these islets following short-term storage in culture solution (‘culture’) , allowing successful xeno transplantation of the pig islets in mice (5,6), rats (7), and monkeys (8) .

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 (9). However, I kept an archive with photocopies of our abstracts published in print in the Abstract Book of the 7th IPITA , posted below.

One of our papers was included among the top 10 papers selected for submission of a full paper in a special issue of the journal Cell Transplantation — see below.

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 — collaborative research of our Surgery Department (LUMC), and workers of the Biomedical Primate Research Centre in Rijswijk (Netherlands) — 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 (9) , and the full paper included in a special issue of the journal Cell Transplantation (10).

Our studies , together, demonstrated the importance of both donor organ selection (choosing adult organs), selection of non-toxic, endotoxin-free media, such as iodixanol and UWS, as the isolation solutions, and selection of islets that survive storage in culture, for a successful outcome after transplantation in this difficult model of xeno-transplantation, grafting porcine islets in other species.

Notes

1) Innovative Islet Purification in Iodixanol-UWS • IPITA 97 • Michel van der Burg • Miracles.Media • @1MEMO 20250128 • URL michelvanderburg.com/2025/01/28/

2a) Iodixanol-UWS Purification for Porcine Islet Transplantation • AIDSPIT 1998 • Michel van der Burg • Miracles.Media • @1MEMO 20250131 • URL michelvanderburg.com/2025/01/31/

2b) Fresh vs Cultured Pig Islets for Xenografts • NTV Bootcongres 1998 • Michel van der Burg • Miracles.Media • @1MEMO 20250201 • URL michelvanderburg.com/2025/02/01/

3) Matsumoto S, Zhang H J, Gilmore T, van der Burg MPM, Sutherland DER, Hering BJ. Large scale isopycnic islet purification utilizing non-toxic, endotoxin-free media facilitate immediate single-donor pig islet allograft function (Abstract). Transplantation 1998; 66: S30 • 1MEMO_20260326_10 • Michel van der Burg • Miracles.Media • TakeNode a7e8ec21-1757-45f4-90c6-1a5f457e0d9f , View/download PDF below.

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Presentation at the 24th Annual Scientific Meeting of the American Society of Transplant Surgeons, Chicago (USA) May 1998. 24th ASTS Program book, Abstract #A-120 • 1MEMO_20260326_5 • Michel van der Burg • Miracles.Media • TakeNode 9efdd5cb-f6da-4dec-b9d9-63cf0b254b30

4) Van der Burg MPM, Ranuncoli A, Molano R, Kirlew T, Ringers J, Bouwman E, Terpstra OT, Ricordi C. New powerful tool for human islet purification: OptiPrep-UWS? 7th World Congress of the International Pancreas & Islet Transplant Association, Sydney (Australia) August 22–25, 1999. Abstract in Programme and Abstract Book, page 169, P298 . In : 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/

5) Van der Burg MPM, Rijkelijkhuizen JKRA, Zwaan RP, Bouwman E. Recovery of adult pig islets during isolation using Liberase vs collagenase-P, purification in OptiPrep-UWS, and culture for transplantation in nude mice. 7th World congress of the International Pancreas & Islet Transplant Association, Sydney (Australia) August 22–25, 1999. Programme and Abstract Book, page 164, #281 . 1MEMO_20241203_3 • In : Iodixanol Purification of Porcine Islets • Sydney IPITA 1999 • 1MEMO 20241203 • Michel van der Burg • Miracles.Media • TakeNode 64ace253-d25b-4b6d-af5b-08060712c471 • URL michelvanderburg.com/2024/12/03/

6) Rijkelijkhuizen JKRA, Bouwman E, Van der Burg MPM. Pre-transplant culture markedly improves pig islet graft survival in nude mice. 7th World congress of the International Pancreas & Islet Transplant Association, Sydney (Australia) August 22–25, 1999. Programme and Abstract Book, page 117, #162 . 1MEMO_20260326_6 • Michel van der Burg • Miracles.Media • TakeNode 5ce0c54f-a6a1-4cc9-8f68-9a1cd723badf

7) Rijkelijkhuizen JKRA, Van der Burg MPM, Bouwman E. Longterm survival of porcine islets in the rat. 7th World congress of the International Pancreas & Islet Transplant Association, Sydney (Australia) August 22–25, 1999. Programme and Abstract Book, page 112, #152 . 1MEMO_20260326_7 • Michel van der Burg • Miracles.Media • TakeNode bc9a48ee-23ff-48f1-ab2c-5bcef071ebaa

8) Rijkelijkhuizen JKRA, Bouwman E, Van der Burg MPM, Ringers J, Ossevoort MA, Kuhn EM, Frost P, Jonker M. Successful suppression of the early rejection of pig islets in monkeys. 7th World congress of the International Pancreas & Islet Transplant Association, Sydney (Australia) August 22–25, 1999. Programme and Abstract Book, page 144, #231 . 1MEMO_20260326_8 • Michel van der Burg • Miracles.Media • TakeNode 29bb03b4-8b02-4aa9-9b33-715ca006c28e

9) Ricordi C. Prime Time for Pancreas and Islet Transplantation at the Turn of the Millennium. Cell Transplant. 2000 Nov;9(6):853-855. doi: 10.1177/096368970000900611. PMID: 28886292. URL https://journals.sagepub.com/doi/epdf/10.1177/096368970000900611 (Free Full Paper)

10) Rijkelijkhuizen JK, Bouwman E, van der Burg MP, Ringers J, Ossevoort MA, Kuhn EM, Frost P, Jonker M. Successful suppression of the early rejection of pig islets in monkeys. Cell Transplant. 2000 Nov-Dec;9(6):909-12. doi: 10.1177/096368970000900618. PMID: 11202577. URL https://journals.sagepub.com/doi/epdf/10.1177/096368970000900618 (Free Full Paper) • Collaborative research From Biomedical Primate Research Centre (M.O., E.M.K.,
J.W., K.H., M.J.), Rijswijk, and Leiden University Medical Centre (J.K.R.A.R., J.R., M.vdB., E.B.), Leiden, The Netherlands .

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)

Cultured pig islets for xenotransplantation • 1MEMO_20260326_11 • Michel van der Burg • Miracles•Media • TakeNode bd15f087-29cd-4e99-a555-9fbfbd1729bc • Reflection contrast microscopy (ultrathin section) of 1-week cultured pig islets . During storage in culture remodeling of the isolated islets occurs, showing rounded islets , with some central necrosis after prolonged culture. Transplantation of 1250 islets (IEQs) from this same 1-week cultured pig islet preparation cured all (n=3) diabetic nude mice indefinitely (over 150 days). In contrast transplants of freshly isolated islets (not cultured) using the same dose of 1250 islets (IEQs) from this same islet preparation, did not cure diabetic nude mice (n=2). Adult pig pancreas procurement by Michel van der Burg from the nearby Westgeest slaughterhouse (in Zoetermeer) facility for large sows processing by Ballering Export (Son, Netherlands; a company of second cousins, of mine).
. Islet isolation (using Iodixanol-UWS) and transplants team work by Josephine Rijkelijkhuizen and Michel van der Burg, Leiden Islet Laboratory (LUMC), May 1998. Reflection contrast microscopy by Frans A. Prins and Michel van der Burg. Not previously published data and photo by Michel van der Burg.

#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 #Rijkelijkhuizen #Matsumoto #Hering #Minneapolis #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

7th IPITA World Congress 1999 • 1MEMO_20260325_1 • Michel van der Burg • Miracles•Media • TakeNode 770715b8-ca68-4c00-8a24-24fe0d216c10

Poster presentation (#P298) Michel van der Burg, 7th World Congress of the International Pancreas & Islet Transplant Association, Sydney (Australia) August 22–25, 1999 (1).

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

1) Van der Burg MPM, Ranuncoli A, Molano R, Kirlew T, Ringers J, Bouwman E, Terpstra OT, Ricordi C. New powerful tool for human islet purification: OptiPrep-UWS? 7th World Congress of the International Pancreas & Islet Transplant Association, Sydney (Australia) August 22–25, 1999. Abstract in Programme and Abstract Book, page 169, P298 .

Abstracts of previous IPITA meetings had been published in print in scientific journals (2), 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 (3).
I kept an archive with photocopies of our abstracts published in print in the Abstract Book of the 7th IPITA. Below 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

A previous poster on this human islet work had been presented at the 4th International congress of the Cell Transplant Society, Montreux (Switzerland) March 21–24, 1999. See:
Optiprep For Human Islet Purification • Cell Transplant Society 1999 • Michel van der Burg • Miracles.Media • @1MEMO 20250203 • URL michelvanderburg.com/2025/02/03/

A previous talk on this human islet work had been presented Monday, 25 January 1999, at the 18th Workshop of the AIDSPIT Study Group in Igls , Austria. See :
Efficacy of the novel iodixanol-UWS density gradient for human islet purification • Igls Aidspit 1999 • Michel van der Burg • Miracles.Media • 20241202 • URL michelvanderburg.com/2024/12/02/

2) Innovative Islet Purification in Iodixanol-UWS • IPITA 97 • Michel van der Burg • Miracles.Media • @1MEMO 20250128 • TakeNode • URL michelvanderburg.com/2025/01/28/

3) Ricordi C. Prime Time for Pancreas and Islet Transplantation at the Turn of the Millennium. Cell Transplant. 2000 Nov;9(6):853-855. doi: 10.1177/096368970000900611. PMID: 28886292. URL https://journals.sagepub.com/doi/epdf/10.1177/096368970000900611

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/

Iodixanol-UWS Purification and Culture of Pig Islets Xeno Transplants • Cell Transplant Society 1999 • @1MEMO 20250202

Iodixanol-UWS Purification and Culture of Pig Islets Xeno Transplants • Cell Transplant Society 1999 • Michel van der Burg • Miracles.Media • @1MEMO 20250202

Slideshow (digitally remastered) oral presentation Michel van der Burg, Cell Transplant Society congress 1999 in Montreux, Switzerland (1)

The Leiden Islet Laboratory developed a novel Iodixanol-UWS density gradient for purification of the islets of Langerhans from the pancreas in the difficult pig model.

Pig islet isolation from the pancreas of slaughterhouse sows was markedly improved by keeping the islets in the UW donor organ preservation solution (UWS) both during the isolation of islets (using the Liberase enzyme blend) and purification of the islets using our novel Iodixanol-UWS density gradient.

Xeno transplantation of these 1-day-cultured pig islets restored normal blood sugar levels in diabetic mice.

PDF slideshow oral presentation Michel van der Burg, Cell Transplant Society congress 1999 in Montreux, Switzerland

Iodixanol-UWS Purification and Culture of Pig Islets Xeno Transplants • Cell Transplant Society 1999 • Michel van der Burg • Miracles.Media • @1MEMO 20250202_2 • TakeNode 8bd79256-78b2-4d8e-8d48-6da41102dc2d • Download file available below 1MEMO_20250202_2

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Notes

1) Van der Burg MPM, Rijkelijkhuizen JKRA, Zwaan RP, Bouwman E. Adult pig islet recovery during Liberase isolation, OptiPrep purification and culture for transplantation in nude mice. 4th International congress of the Cell Transplant Society, Montreux (Switzerland) March 21–24, 1999 .

2) Van der Burg MPM, Rijkelijkhuizen JKRA, Zwaan RP, Bouwman E. Adult pig islet recovery during Liberase isolation, OptiPrep purification and culture for transplantation in nude mice (Abstract). Cell Transplant 1999; 8: 185. Download abstract, available below 1MEMO_20250202_3

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Citation info : Iodixanol-UWS Purification and Culture of Pig Islets Xeno Transplants • Cell Transplant Society 1999 • Michel van der Burg • Miracles.Media • @1MEMO 20250202 • TakeNode f9d1fdc5-21e4-4932-b995-4c97639945fe • URL michelvanderburg.com/2025/02/02/

Fresh vs Cultured Pig Islets for Xenografts • NTV Bootcongres 1998 • @1MEMO 20250201

Fresh vs Cultured Pig Islets for Xenografts • NTV Bootcongres 1998 • Michel van der Burg • Miracles.Media • @1MEMO 20250201_1 • TakeNode 71d39e7e-ab5e-42b6-8cf2-a17d464ce132

Van der Burg MPM, Rijkelijkhuizen JKRA, Zwaan RP, Bouwman E. Culture of isolated pig islets pre-xenotransplantation greatly improves the quality and survival of the graft (Kweek van geïsoleerde varkenseilandjes pre-xenotransplantatie verbetert aanzienlijk de kwaliteit en overleving van het transplantaat). Tenth Congress of the Dutch Transplantation Society (Bootcongres 1998), Kerkrade (The Netherlands) April 21–23, 1998.

Download (pdf) NTV bulletin (abstract) & poster , file 1MEMO_20250201

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EN – Abstract

PRE-TRANSPLANT SHORT-TERM CULTURE OF ISOLATED PIG ISLETS MARKEDLY IMPROVES THE QUALITY AND SURVIVAL OF THE XENOGRAFT
Van der Burg MPM,* Rijkelijkhuizen JKRA, Zwaan RP, and Bouwman E, Leiden University Medical Centre, Leiden, The Netherlands.

Pre-transplant culture of isolated islets reduces the graft’s immunogenicity in various models. Little is known, however, on the effect of culture in pig islet xenotransplantation — probably, because porcine islets have been found difficult to culture. Because pilot transplants of freshly-isolated pig islets in strongly immunosuppressed rats resulted in primary non function, we first studied 1-7 day culture of the isolated pig islets at 37°C in RPMI plus 10% porcine serum. Islets were isolated from large sows (n =6) by an improved method, resulting in intact islets (size 185±16 µm) and no loss during purification, yielding 2448 islets (IEQs)/g with a >95% purity and 90±2% viability as assessed by acridine orange – propidium iodide (AOPI) staining. During culture, however, islet recovery was 24±9% at day 1 and 17±6% at day 7 (NS vs day 1). In order to delineate whether the culture conditions or the quality of freshly isolated islets caused the islet loss during culture, we compared graft survival in nude mice at 1 mo after transplantation under the kidney capsule of ~2500 fresh islets in normoglycemic recipients or ~1000 cultured islets in STZ-diabetic (>20 mM) recipients. After transplanting fresh islets, histology of the kidneys — sectioned every 500 µm — demonstrated substantial scarring and (near-)absence of islets. Cultured islet transplants, by contrast, rendered 5/6 recipients normoglycemic, and showed a substantial mass of well-preserved islets with little scarring at the grafts’ site. Thus, viability by AOPI-staining of fresh islets poorly predicts the survival in vivo and in vitro. A non-immune mediated disintegration of part of the fresh islets may substantially reduce the functional capacity of the graft, both direct by lowering the effective islet dose, and indirect first because scarring may hamper the engraftment of viable tissue, and second because the cellular debris most probably will attract macrophages and induce the release of harmful cytokines.

Citation info : Fresh vs Cultured Pig Islets for Xenografts • NTV Bootcongres 1998 • Michel van der Burg • Miracles.Media • @1MEMO 20250201 • URL michelvanderburg.com/2025/02/01/

Iodixanol-UWS Purification for Porcine Islet Transplantation • AIDSPIT 1998 • @1MEMO 20250131

Iodixanol-UWS Purification for Porcine Islet Transplantation • AIDSPIT 1998 • Michel van der Burg • Miracles.Media • @1MEMO 20250131

Slideshow (digitally remastered) of first talk on pancreatic islet xeno-transplantation following adult pig islet purification in our novel Iodixanol-UWS density gradient. Presented at the 17th Workshop of the AIDSPIT Study Group in Igls, Austria, Tuesday, Jan 27, 1998 (1, 2).

Isolation of porcine pancreatic islets (from the pancreas of large sows) was markedly improved by keeping the islets in the UW donor organ preservation solution (UWS) both during the isolation of islets (using the Liberase enzyme blend) and purification of the islets using a novel Iodixanol-UWS density gradient.
Transplantation of the pig islets (after 1 day storage in culture solution) restored normal blood sugar levels in diabetic mice.

Notes

1) Van der Burg MPM, Zwaan RP, Bouwman E. Markedly improved outcome of adult porcine islet isolation, purification, and culture using Liberase-PI versus collagenase-P, and a novel gradient of Optiprep in University of Wisconsin solution. 17th Workshop of the Study Group on Artificial Insulin Delivery Systems, Pancreas and Islet Transplantation (AIDSPIT) of the European Association for the Study of Diabetes (EASD), Igls (Austria) January 25—27,1998

2) Van der Burg MPM, Zwaan RP, Bouwman E. Markedly improved outcome of adult porcine islet isolation, purification, and culture using Liberase-PI versus collagenase-P, and a novel gradient of Optiprep in University of Wisconsin solution (Abstract). Horm Metab Res 1998; 30(1): A23 . DOI: 10.1055/s-2007-978834 .
Download abstract 1MEMO_20250131_2 below :

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Updates

Update 20260123 : Handout pdf (1MEMO_20250131_3) for download added.
Download handout presentation (1MEMO_20250131_3) below.

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Citation info : Iodixanol-UWS Purification for Porcine Islet Transplantation • AIDSPIT 1998 • Michel van der Burg • Miracles.Media • @1MEMO 20250131 • TakeNode 1f185515-7aeb-44ac-b721-2cec76df67b7 • URL michelvanderburg.com/2025/01/31/

Innovative Islet Purification in Iodixanol-UWS • IPITA 97 • @1MEMO 20250128

No porcine islet loss during density gradient purification in a novel iodixanol in University of Wisconsin solution. First talk on our introduction of the innovative Iodixanol-UWS density gradients for islet purification , showing no islet loss in the difficult model of pig islet isolation — presented at the 6th IPITA congress in Milan (Italy) , Thursday, 25th september 1997 (1).

Background

In 1995 the Leiden Islet Lab had moved into the Surgery Lab in the new LUMC building, and the islet team had grown, focussing on xenotransplantation. With more people isolating pig islets, more convenient islet isolation solutions were tried.

Both Percoll-UWS (2) and Histopaque-UWS (3) were being used from 1992 in first series of islet isolations from juvenile pig pancreases.

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 (2) — 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.

July 1996, I introduced the Iodixanol-UWS gradient to replace the Percoll-UWS gradient for large scale pancreatic islet research in this difficult model of islet isolation from juvenile pig pancreases.

The work was presented September 1997. First a poster was presented that month at the Xenotransplantation Congress in Nantes , France (4). Next, two talks followed at the 6th Congress of the International Pancreas and Islet Transplant Association (IPITA) in Milan (Italy).

Here the (remastered) slideshow of that first talk at the 6th IPITA Congress in Milan, presented Thursday, 25th september 1997 (1) . The slideshow of the 2nd talk , presented at the last day of that congress, was posted yesterday (5).

Notes

1) Van der Burg MPM, Basir I, Bouwman E. No porcine islet loss during density gradient purification in a novel iodixanol in University of Wisconsin solution. Sixth Congress of the Int. Pancreas and Islet Transplant Association (IPITA), Milan (Italy) Sept. 24–27, 1997.

2) Percoll UWS Purification Pancreatic Islets • ESOT 1991 Talk • Michel van der Burg • Miracles.Media • @1MEMO 20250114 • URL michelvanderburg.com/2025/01/14/

3) Basir I, van der Burg MPM, Scheringa M, Töns A, Bouwman E. Improved outcome of pig islet isolation by Pefabloc inhibition of trypsin. Transplant Proc. 1997 Jun;29(4):1939-41. doi: 10.1016/s0041-1345(97)00168-1. PMID: 9193462

4) 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. Online in : Purification Islets in Iodixanol-UWS • Leiden Start 1996 • Michel van der Burg • Miracles.Media • @1MEMO 20250126 • URL michelvanderburg.com/2025/01/26/

5) Van der Burg MPM, Basir I, Zwaan RP, Bouwman E. Porcine islet preservation during isolation in University of Wisconsin solution. Sixth Congress of the Int. Pancreas and Islet Transplant Association (IPITA), Milan (Italy) Sept. 24–27, 1997. Online in : Porcine Islet Preservation In UWS • IPITA 97 • Michel van der Burg • Miracles.Media • @1MEMO 20250127• URL michelvanderburg.com/2025/01/27/

Milan Papers • @1MEMO 20250205 • Manuscripts (Preprints) and Abstracts copies of the presentations at the IPITA 1997 meeting in Milan (Italy). PDF downloads at michelvanderburg•com/2025/02/05/

Citation info : Innovative Islet Purification in Iodixanol-UWS • IPITA 97 • Michel van der Burg • Miracles.Media • @1MEMO 20250128 • TakeNode • URL michelvanderburg.com/2025/01/28/

Porcine Islet Preservation In UWS • IPITA 97 • @1MEMO 20250127

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 in 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 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.

The work was first presented September 1997, both in a poster presented at the Xenotransplantation Congress in Nantes , France (1), and later that month in two talks at the 6th Congress of the International Pancreas and Islet Transplant Association (IPITA) in Milan (Italy). The slideshow of the first talk (2) will be online at this site soon.
Here the remastered slideshow of the 2nd talk at the 6th IPITA Congress in Milan, presented Saturday, 27th September, 1997 (3).

Notes

1) 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. Online in : Purification Islets in Iodixanol-UWS • Leiden Start 1996 • Michel van der Burg • Miracles.Media • @1MEMO 20250126 • URL michelvanderburg.com/2025/01/26/

2) Van der Burg MPM, Basir I, Bouwman E. No porcine islet loss during density gradient purification in a novel iodixanol in University of Wisconsin solution. Sixth Congress of the Int. Pancreas and Islet Transplant Association (IPITA), Milan (Italy) Sept. 24–27, 1997.

3) Van der Burg MPM, Basir I, Zwaan RP, Bouwman E. Porcine islet preservation during isolation in University of Wisconsin solution. Sixth Congress of the Int. Pancreas and Islet Transplant Association (IPITA), Milan (Italy) Sept. 24–27, 1997.

Update 20250128 – update intro design timeline

Update 20250205 – added Milan papers

Citation info : Porcine Islet Preservation In UWS • IPITA 97 • Michel van der Burg • Miracles.Media • @1MEMO 20250127 • TakeNode 6d6fca2e-014c-40cf-8110-725b267c0b0e • URL michelvanderburg.com/2025/01/27/