In the last
several years, beta cell encapsulation
research has become a high priority for JDRF. For well over a decade,
researchers have been able to restore insulin function to some degree in people
with type 1 diabetes (T1D) by transplanting insulin-producing islets recovered
from deceased donors. However, the trade-off for these islet recipients is a
life-long requirement to take strong drugs that suppress the immune system and
prevent it from rejecting the transplanted cells. These powerful drugs are not
appropriate for children with T1D and can result in potentially severe side
effects. Also, these procedures are available only to people with the most
uncontrolled T1D, because of the limited supply of donated islets (from
deceased organ donors) and the required immune-system suppression.

The goal of
JDRF’s encapsulation research program is to solve both of these limitations by
developing materials to protect implanted beta cells from the body’s immune
attack and developing new beta cell sources so that these procedures will be
available to all who may benefit from them. For people with T1D, achieving this
goal would mean they could receive an implant
of insulin-producing beta cells that are protected  from the immune system, thereby eliminating their dependence on external insulin through a simple procedure.

A study recently published in Proceedings
of the National Academy of Sciences
provides further demonstration that implanting encapsulated beta cells can be
beneficial to individuals with T1D. In the study, researchers led by Stefan
R. Bornstein, M.D., Ph.D., at the Carl Gustav Carus University Hospital in
Dresden, Germany, implanted functional
islet cells from the pancreas of a deceased organ donor into a 63-year-old man who
had had T1D for 54 years and who showed no evidence of residual beta cell
function. The cells were encapsulated in a specially designed chamber composed
of a combination of alginate and other materials and supplied with oxygen (crucial
to the cells’ survival). After evaluating the recipient for 10 months following
the implantation, the researchers reported two significant results:

 1)     
the patient showed modest increases in
C-peptide, indicating that the implanted cells were producing small levels of
insulin on their own, and

2)     
the body’s immune system did not show signs of having
destroyed the implanted cells, indicating that the encapsulation device successfully
protected the islets, allowing them to survive for the full 10 months of the
trial.

These
results are significant because they represent the first time that encapsulated
human islet cells have been successfully implanted into a person with T1D and
maintained their insulin-producing function over a prolonged period of time
without the need for drugs to suppress the immune system. This new finding is
strong evidence that islet cell encapsulation has the potential to successfully
achieve its goals. The combination of the encapsulation material and the oxygen
supply seems to have successfully shielded the cells from attack by the body’s
immune system and kept them healthy and functioning for almost a year.

While these
results are promising, it’s important to note that this study involved only a
single patient and led to only modest benefits for the recipient. While his hemoglobin
A1c levels and insulin requirements were lowered slightly, he still needed to
give himself insulin and test his blood-glucose levels. According to JDRF Vice President
of Cure Therapies Julia
L. Greenstein, Ph.D., this study is exciting and clearly showed “the
ability to maintain some function without immunosuppression.” However,
according to Dr. Greenstein, “it’s a study of one patient, and the level of
C-peptide wasn’t enough to significantly impact the clinical situation of the
recipient.” While the study didn’t meet the goals of normal blood-sugar levels
or insulin independence, it’s “one early step on the way to developing a
practical approach to providing islet function for a person with type 1
diabetes.”

While JDRF
did not fund this particular study, it is consistent with our efforts to
achieve insulin independence in people with T1D using implanted encapsulated
islets. JDRF has been a leader in this field and has made a significant
investment in research to develop effective means to encapsulate islets
using alginate and other
materials. While these materials and the current study would address the need
to protect islets from the immune system, JDRF is taking it a step further and
also funding research to address the problem of islet supply. While the current
study used islets from a deceased organ donor, that’s not a feasible solution
for the larger T1D population, because of the limited availability of such
cells. JDRF-funded
research using pig islets (xenotransplantation) combined with encapsulation
is already showing positive
indicators in human trials. And JDRF-funded
research using islets derived from stem cells in combination with
encapsulation is expected to begin human clinical trials next year. Finally, the
recent launch of the JDRF Encapsulation Consortium, which
brings together a collaborative group of key players in science, engineering,
and medicine to share their research to advance encapsulation technology,
ensures that JDRF will continue to drive this promising research forward toward
next-generation encapsulation therapies that yield more significant benefits to
individuals with T1D.