Surface modification of polyurethanes with covalent immobilization of heparin

2007-10-04
Thrombus formation and blood coagulation is a major problem associated with blood contacting products such as catheters, vascular grafts, arteries, artificial hearts and heart valves. An intense research is being conducted towards the synthesis of new hemocompatible materials and modifications of surfaces with biological molecules. In this study, polyurethane (PU) films were synthesized in medical purity from diisocyanate and polyol without using any other ingredients and their surfaces were modified by covalent immobilization of heparin. Two types of heparin, unfractionated (UFH) and low molecular weight heparin (LMWH), were immobilized to investigate their effect on cell adhesion. The surface properties of the modified PUs were examined with ESCA, ATR-FTIR and AFM. ESCA results demonstrated sulfur peaks indicating the presence of heparin and AFM results showed the alteration of surface structure after coating with heparin. Cell adhesion studies were conducted with heparinized whole human blood. The surfaces of the UFH immobilized films resulted in lesser red blood cell adhesion in comparison to LMWH demonstrating strong antithrombogenic activity of the latter.
4th European Symposium on Biopolymers

Suggestions

Synthesis and surface modification studies of biomedical polyurethanes to improve long term biocompatibility
Aksoy, Eda Ayşe; Hasırcı, Nesrin; Department of Polymer Science and Technology (2008)
Thrombus formation and blood coagulation is a major problem associated with blood contacting products such as catheters, vascular grafts and artificial hearts. An intense research is being conducted towards the synthesis of new hemocompatible materials and mdifications of surfaces with biological molecules. In this study, polyurethane (PU) films were synthesized in medical purity from diisocyanate and polyol without using any other ingredients and the chemical, thermal and mechanical properties were charact...
Polyurethanes in biomedical applications
Burke, A; Hasırcı, Nesrin (2004-01-01)
Polyurethanes are the most commonly used materials in the production of blood contacting devices such as heart valves or artificial veins and arteries. They comprise a large family of materials with the only common characteristic of the presence of urethane linkages along the large molecular chains. In general urethane linkages form by the reaction of isocyanates and alcohols. During the preparation and the curing processes of polyurethanes, besides the formation of urethane linkages, many other reactions t...
Surface modification of Ti6Al4V by micro-arc oxidation in AgC2H3O2-containing electrolyte
Aydogan, Dilek Teker; Muhaffel, Faiz; Acar, Ozge Karabiyik; Topcuoglu, Emine Nursen; Kulekci, Hatice Guven; Kose, Gamze Torun; Baydoğan, Murat; Çimenoğlu, Hüseyin (2018-09-01)
This study focuses on the biological properties of Ti6Al4V after employing micro-arc oxidation in sodium phosphateand calcium acetate-containing electrolyte with and without addition of silver acetate. After micro-arc oxidation process, structural features of the surfaces were analyzed by using an energy dispersive X-ray spectrometer equipped scanning electron microscope, an X-ray diffractometer and a Fourier transform infrared spectroscope. The micro-arc oxidation process generated multilayer coatings comp...
Tissue engineering of small diameter vascular grafts by using pcl/collagen based scaffolds
Öncü, Sepren; Hasırcı, Vasıf Nejat; Department of Biology (2013)
Cardiovascular system is composed of the heart, blood vessels and blood. This system consists of five types of blood vessels: arteries, arterioles, veins, venules and capillaries. Cardiovascular diseases (CVDs) including diseases of coronary arteries and blood vessels of the brain are responsible for 17.3 million deaths a year in the world. Atherosclerosis is the main reason for CVDs which is the hardening and thickening of arterial walls with lipid molecules and affects especially the walls of medium and l...
CRACK PHASE-FIELD MODELING OF ANISOTROPIC RUPTURE IN FIBROUS SOFT TISSUES
GUELTEKIN, O.; Dal, Hüsnü; HOLZAPFEL, G. A. (2017-09-07)
The estimation of rupture in fibrous soft tissues has emerged as a central task in medical monitoring and risk assessment of diseases such as aortic dissection and aneurysms. In an attempt to address the challenges we have established a computational framework within the context of crack phase-field modeling and proposed an energy-based anisotropic failure criterion based on the distinction of isotropic and anisotropic material responses. Numerically we compare that criterion with other anisotropic failure ...
Citation Formats
A. AKSOY, V. N. Hasırcı, and N. Hasırcı, “Surface modification of polyurethanes with covalent immobilization of heparin,” Kusadasi, TURKEY, 2007, vol. 269, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/29975.