Islet Microencapsulation

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Islet Microencapsulation

• Presented by
• Kristen Galea

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Outline

• Need for Islet microencapsulation
• Isolation of Islet cells
• Microencapsulation process
• Implantation
• Cost

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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)

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Diabetes

• Type 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

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What are the Alternatives?

• Pancreas Transplant
• Invasive surgery
• Immunosuppressive drugs required
• Islet Transplant
• Less invasive surgery than transplant
• Immunosuppressive drugs
• Microencapsulated Islet Transplant

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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

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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

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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

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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

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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

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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

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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

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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

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Cost

• Medical grade Sodium Alginate
• Protanal - FMC BioPolymer
• Production of Microencapsulated Islet cells
• Islet Technology Minnesota
• Estimated cost per transplant
• 150 000 - 175 000 USD

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Questions