Islet
Microencapsulation
Presented by:
Kristen Galea
Outline
 Need
for Islet microencapsulation
 Isolation of Islet cells
 Microencapsulation process
 Implantation
 Cost
Where do Islets cells come
from?
 Pancreas



1 – 1.5 million Islets of Langerhans - 2%
of the mass of the pancreas
Each Islet contains 2000 – 10000 cells
75% beta cells, 20% alpha cells, D cells
and PP cells (or F cells)
Diabetes
1 diabetes – autoimmune disease
 Body kills off the Beta cells
 Insulin dependant
 Insulin shots do not imitate blood glucose
levels of non-diabetics
 Approximately $600 000 USD in a
diabetics lifetime on medication
 Type
What are the Alternatives?
 Pancreas


Invasive surgery
Immunosuppressive drugs required
 Islet


Transplant
Transplant
Less invasive surgery than transplant
Immunosuppressive drugs
 Microencapsulated
Islet Transplant
Microencapsulation
 Microencapsulation
is the process of
covering singular cells in a capsule
 Important in Diabetes research


Eliminates the need for insulin injections
No immunosuppressive drugs are required
Isolating Islet Cells
 Must
isolate insulin producing cells from
pancreas
 Requires a pancreas – high demand for
organs
 Long and delicate procedure

Do not want to damage cells in the process
Isolation Process

Ricordi Chamber
 Add Collagenase (an enzyme) to pancreas
 Placed in Chamber for digestion phase
 Chamber contains glass beads
 Gently agitated
 Small pieces are filtered
 Continuous circulation of enzyme through the
chamber
Isolation Process




Fresh medium is flushed through
system to stop enzymatic reaction
Islets are purified
Tested for viability and purity
Sufficient number of cells for transplant
• 5000 Islets per kilogram of body weight
Materials for Microencapsulation
 Biocompatible
 Protect
cell from immune rejection
 Semipermeable membrane

Allows insulin and nutrients to pass through
 Current


research
Sodium Alginate – isolated from the seaweed
(kelp) Macrocystis pyrifera
Poly L-lysine
Microencapsulation Process
 Mixture
of cells and sodium alginate is
prepared
 Passed through an airjet (or needle)
 Droplets formed
 Placed in a calcium chloride solution
where a gel forms
Microencapsulation Process
 Gel
reacts with Poly L-lysine
 Membrane formed around cells
 Calcium must be removed from the
capsule
 Place cells in a Sodium Chloride solution
 Semipermeable membrane outside, liquid
core
Implantation
 Implanted



into wall of abdominal cavity
Blood vessels in cavity bind to capsule
Functions as a new organ
Nutrients carried into capsule and insulin
carried out into blood stream
 Simple
and easy process compared to an
organ transplant
Cost
 Medical

grade Sodium Alginate
Protanal® - FMC BioPolymer
 Production

Islet Technology – Minnesota
 Estimated

of Microencapsulated Islet cells
cost per transplant:
$150 000 - $175 000 USD
Questions