Multilayer Nanoencapsulation

                   ----------  New Approach for Immune Protection of Human Pancreatic Islets

Static insulin release for human pancreatic islets to different glucose (G) levels. The islets were coated with polyelectrolytes with an odd or even number of layers as well as with different polymers at different molecular weights. y-axis is insulin (íU/mL); x-axis is the stimulating substance. The bars indicate the SD. (A) Uncoated (filled column) and islets coated with PDADMAC/PSS (thickly striped column), (PDADMAC/PSS)2 (thinly striped column), and (PDADMAC/PSS)3 (empty column) polyelectrolyte layers. (B) Uncoated (filled column) and islets coated with PAH(15 kDa)/PSS (thickly striped column) and PAH(70 kDa)/PSS (thinly striped column). (C) Uncoated (filled column) and PAH(15 kDa)/PSS/PAH(15 kDa)-coated islets (striped column).

Electronmicrographs of (A) uncoated and (B) PAH/PSS/PAH-coated islets. Morphology of the coated cells is comparable to the uncoated ones.

Fluorescence microscopy of (A) uncoated islets and (B) PAH/PSS/PAH coated human pancreatic islets. The fluorescence is due to FITC-labeled anti-GAD(+) antibodies and autofluorescence of the islets. The coating prevents the recognition of the islets by the antibody.

Summary

The results led to the conclusion that encapsulation with only a nanometer thin but multilayered coating can be a new approach to create multifunctional capsule for immune protection of artificial tissue. Future experiments should show that a capsule with three regions which fulfill different functions is an intelligent system to overcome several problems in protection of the graft and also prevention of transplant rejection for xenotransplants.

Designed by Shan Yang