Immunoisolation Techniques

I. Introduction .................................................................................................................... 189

II. Theory and Capsule Format ........................................................................................... 190

III. Cell Sourcing .................................................................................................................. 191

IV. Host Immune Responses to Encapsulated Cells ........................................................... 192

V. Conclusion ...................................................................................................................... 193

References ................................................................................................................................... 193

Appendix 1. Immunoisolation .................................................................................................... 197

Replacement of the vital functional physiology of irreparably damaged native organs has been the

goal of both transplantation medicine and immunoisolatory medicine. Although transplants of

allogeneic tissue carry the promise of complete metabolic restoration, they are beset with several

problems. Limited donor supply of transplantable organs along with the immunosuppressive

regimen that follows transplantation hinders sufficient organ supply and efficacy. Alternative

treatments to transplantation such as administration of therapeutic proteins designed to replace

metabolic deficiencies are also limited. Restrictions include the routes of administration, enzymatic

degradation, inability to maintain therapeutic levels of drug, bioavailability, and ultimately, cost.

This type of therapy requires stringent monitoring of delivered doses of therapeutic proteins since

the system itself is not reactive to changes in the patient’s physiological status. Immunoisolation

and transplantation of protein-secreting cells is a viable option for the replacement of protein-

secreting tissues and potentially whole organs.