Piotr Witkowski, MD, PhD

Assistant Professor of Surgery
Director, Pancreatic Islet Transplantation

The University of Chicago Medical Center,
Department of Surgery
Division of Abdominal Organ Transplantation
5841 S. Maryland Ave. MC5027, Room J-517
Chicago, IL 60637
tel 773 702 2447
fax 773 702 2126

 

Education
MD - Medical University of Gdansk, Poland
Residency - Medical University of Gdansk, Poland
Research Fellowship - Columbia University, New York, NY
Transplant Fellowship - Columbia University Medical Center, NY

 

 

Witkowski Group Links

Clinical Interests

 

 

Clinical Research

Human Islet Transplantation in Diabetes Type I

We are a team of scientists working in collaboration with transplant clinical staff to provide human islet cells from donated organs to subjects enrolled in our clinical trial. Our goal is to relieve the dangerous side effects of diabetes type I by providing these patients with a supply of endogenous insulin via transplantation.

Our primary interest is to constantly improve the islet isolation process by testing and innovation in the laboratory. We then translate our findings to our cGMP islet isolation facility. Here we collaborate with the GMP (Good Manufacturing Process) team that assures all necessary quality controls. Our team isolates day and night during prefixed call schedules.

Both our GMP facility and basic science laboratory are located in the lower level of the Kovler building (910 East 58th street, Chicago IL 60637). On the left is a picture of the Kolver Research Building.

On the right you can see inside our GMP facility, where five main processes are performed. First the organ is received, cleaned and separated from spleen and duodenum. Second, a collagenase enzyme is infused under pressure into the pancreatic duct. Third, the `pancreas is digested into a “cellular soup”. Fourth, pancreatic islets are purified from the acinar tissue via a density gradient. Finally, the islets are placed in cell incubators until they are ready for use.

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Scientific Research

Islet Encapsulation

We are focusing our research on islet encapsulation using various materials and methods. On the right is a micrograph of a human islet (indicated by the black arrow) still within the pancreas tissue. The next micrograph below shows an isolated rodent islet before encapsulation.

Similar techniques are applied for the isolation of rodent and human islets. The encapsulation process may provide an alternative to the administration of immune suppressive drugs in transplanted patients. Encapsulation acts as a barrier against the transplanted host immune system.

At the same time this allows nutrients and waste to be freely exchanged. On the right, the micrograph shows rodent islets encapsulated via the selective withdrawal method.

Another encapsulation material is shown to the left. The capsules are much larger, can contain many islets and are made from an algae derivative. In the laboratory we evaluate the viability and insulin release of these preparations in vitro. We then proceed to in vivo implantation studies.

We also look at integration and evaluate fibrosis generated by the various materials. An example is shown on the micrograph to the right. The black arrow indicates cellular fibrosis around an algae derived capsule. Other subjects of interest are transplantation site of injection and collaboration on human islet physiology at the University of Chicago Medical Center.


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Islet Isolation Teams

TEAM 2007

From the left to the right, N.Younes M.D. (visiting professor from Jordan and Fulbright Scholar), S.Liu M.D. Ph.D. (Team Senior), D. Ostrega, M.B.A (cGMP Director), J-M Nothias M.S. (Team Chief), M. Shah B.A. (Team Junior).

TEAM 2008

From the left to the right, M. Umehara M.D. (visiting surgeon from Japan), S.Liu M.D. Ph.D. (Team Senior), D. Ostrega, M.B.A (cGMP Director), J-M Nothias M.S. (Team Chief), A. Scavone M.S.E. (Team Junior).

 

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