title: Biomolecular surface engineering of pancreatic islets with thrombomodulin.
abstract: Islet transplantation has emerged as a promising treatment for Type 1 diabetes, but its clinical impact remains limited by early islet destruction mediated by prothrombotic and innate inflammatory responses elicited upon transplantation. Thrombomodulin (TM) acts as an important regulator of thrombosis and inflammation through its capacity to channel the catalytic activity of thrombin towards generation of activated protein C (APC), a potent anticoagulant and anti-inflammatory agent. We herein describe a novel biomolecular strategy for re-engineering the surface of pancreatic islets with TM. A biosynthetic approach was employed to generate recombinant human TM (rTM) bearing a C-terminal azide group, which facilitated site-specific biotinylation of rTM through Staudinger ligation. Murine pancreatic islets were covalently biotinylated through targeting of cell surface amines and aldehydes and both islet viability and the surface density of streptavidin were maximized through optimization of biotinylation conditions. rTM was immobilized on islet surfaces through streptavidin-biotin interactions, resulting in a nearly threefold increase in the catalytic capacity of islets to generate APC.
authors.affiliation: Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30322, USA.
authors.forename: John T
authors.initials: JT
authors.lastname: Wilson
authors.forename: Carolyn A
authors.initials: CA
authors.lastname: Haller
authors.forename: Zheng
authors.initials: Z
authors.lastname: Qu
authors.forename: Wanxing
authors.initials: W
authors.lastname: Cui
authors.forename: Murali K
authors.initials: MK
authors.lastname: Urlam
authors.forename: Elliot L
authors.initials: EL
authors.lastname: Chaikof
mesh_terms: D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D020099:Coated Materials, Biocompatible / Q000737:chemistry* / Q000494:pharmacology*; D007515:Islets of Langerhans / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D008297:Male; D008422:Materials Testing; D051379:Mice; D008810:Mice, Inbred C57BL; D013499:Surface Properties; D018180:Thrombomodulin / Q000008:administration & dosage* / Q000737:chemistry*; D023822:Tissue Engineering / Q000379:methods*
chemical_list: D020099:Coated Materials, Biocompatible; D018180:Thrombomodulin