In this study,
we proposed a double-layer shielding system using of heterobifunctional poly
ethylene glyco, (NHS-PEG-Mal and NHS-PEG-SH) for encapsulation of islets that
it may be possible to
protect islets from immune cell attack and reduce the immunogenicity of islets via generation of a steric barrier. The
PEGylation procedure itself has no negative effects on normal islet structure,
function, or viability 10–12. The covalent
tethering of PEG to islets can form a stable
conformal coating by interaction between NHS-groups of PEG and amine groups on the collagen membrane of the pancreatic islets.
context, PEGylation on the islet surface is not only expected for
immunoprotection as seen above, but also to provide a linker molecule for
conjugation of jagged-1 and another
role could be that of a spacer to enhance the access of ligand on the surface
to its target receptor. Hence the importance of
PEG for modification of islet surface is predesignated to increase stability of PEG on islet surface and conjugation of Jagged-1.
Use of engineered biomaterials with
immunomodulatory agents may be
can presents the opportunity to modulate the immune system locally to see the
transplanted islet cells as “self” and allow them to function normally.
We evaluated this approach by conjugation of
JAG-1to coated heterofunctionalized PEG into islets (Fig.
1). These immuno- modulatory coatings were subsequently explored for
their capacity to convert effector T cells to Treg.