TY - JOUR
T1 - Surface modification of biomedical grade polyurethane to enable the ordered co-immobilization of two proteins
AU - Kador, Karl E.
AU - Subramanian, Anuradha
N1 - Funding Information:
This work was supported by the University of Nebraska, Lincoln Tobacco Settlement Fund. We would like to thank Dr. Steve Taylor and Ms. Julie Nordlee of the Food Allergy Research and Resource Program at the University of Nebraska who donated their time and facilities to complete the radioactivity studies. We would like to acknowledge the National ESCA and Surface Analysis Center for Biomedical Problems and their funding NIBIB grant EB-002027 who conducted the XPS analysis. A special thanks to AdvanSource Biomaterials Inc., who generously donated films of Chronoflex AR medical grade polyurethane. We wish to acknowledge Dr. Sanjukta Guha Thakurta for her assistance in making the figures.
PY - 2011
Y1 - 2011
N2 - Surface modifications of polyurethane (PU)-based implantable materials have the potential to enhance or improve hemo-or cellular-biocompatibility. In general, surface modification methods of PU have included surface treatments, physio-adsorption of desired biomolecules, and the covalent immobilization of reactive or therapeutic biomolecules. When multi-protein immobilizations are desired to mimic the enzymatic reactions found on cells and tissues, it is often necessary to design and develop surface modification strategies that will allow the co-immobilization of proteins. In this study, a surface modification strategy is presented that enables the sequential additional of proteins to a bi-dentate moiety grafted onto the PU surface. The modifications were confirmed via IR and XPS signatures. While the strategy presented is applicable to a wide variety of biomolecules, bovine serum albumin (BSA) and human immunoglobulin (hIgG) were selected as model proteins. A total immobilized protein density of 0.298 ± 0.037 μg/cm2 was obtained, with nearly equal amounts of protein on each arm of the bi-dentate moiety. Proteins immobilizations were also visualized with immunofluorescent staining. Finally, the method proposed in this study was used to demonstrate a significant increase (P < 0.05) in the catalytic conversion of protein C (PC) to activated PC (APC) using sequentially immobilized thrombomodulin (TM) and endothelial PC receptor (EPCR) as compared to the two proteins immobilized onto a surface in random order.
AB - Surface modifications of polyurethane (PU)-based implantable materials have the potential to enhance or improve hemo-or cellular-biocompatibility. In general, surface modification methods of PU have included surface treatments, physio-adsorption of desired biomolecules, and the covalent immobilization of reactive or therapeutic biomolecules. When multi-protein immobilizations are desired to mimic the enzymatic reactions found on cells and tissues, it is often necessary to design and develop surface modification strategies that will allow the co-immobilization of proteins. In this study, a surface modification strategy is presented that enables the sequential additional of proteins to a bi-dentate moiety grafted onto the PU surface. The modifications were confirmed via IR and XPS signatures. While the strategy presented is applicable to a wide variety of biomolecules, bovine serum albumin (BSA) and human immunoglobulin (hIgG) were selected as model proteins. A total immobilized protein density of 0.298 ± 0.037 μg/cm2 was obtained, with nearly equal amounts of protein on each arm of the bi-dentate moiety. Proteins immobilizations were also visualized with immunofluorescent staining. Finally, the method proposed in this study was used to demonstrate a significant increase (P < 0.05) in the catalytic conversion of protein C (PC) to activated PC (APC) using sequentially immobilized thrombomodulin (TM) and endothelial PC receptor (EPCR) as compared to the two proteins immobilized onto a surface in random order.
KW - Co-immobilization
KW - polyurethane
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U2 - 10.1163/092050610X529191
DO - 10.1163/092050610X529191
M3 - Article
C2 - 21047446
AN - SCOPUS:80052060900
SN - 0920-5063
VL - 22
SP - 1983
EP - 1999
JO - Journal of Biomaterials Science, Polymer Edition
JF - Journal of Biomaterials Science, Polymer Edition
IS - 15
ER -