Date of Award
2006
Degree Type
Thesis
Degree Name
Master of Engineering Science
Program
Biomedical Engineering
Supervisor
Dr. Kibret Mequanint
Second Advisor
Dr. Amin S. Rizkalla
Third Advisor
Dr. P. Charpentier
Abstract
Hemocompatibility is one of the design criteria for biomaterials used in blood-contacting applications. Research in the past documented the immobilization of charged groups such as carboxylate and sulfonate ions as one approach for the designing of blood compatible biomaterials. The exact role played by these charged groups was, however, overshadowed by the presence of blood compatible chains other than the ions. The objective of this study was to evaluate the effect of ionic groups on the mechanical and blood response properties of polyurethane biomaterials. Therefore, polyurethanes containing ionic groups both on the soft and hard segments were synthesized to evaluate the distinctive role played by the ionic groups on the mechanical properties and blood compatibility. In order to have ionic groups on the soft segment of polyurethanes, thioglycolic acid (TGA), mercaptopropionic acid (MPA) and sodium 2- mercaptoethanesulfonate (MESNA) were chosen and the experimental conditions were optimized to graft these chemicals onto the double bonds of polybutadiene. To synthesize polyurethanes with ionic groups on the hard segment, dimethylpropionic acid (DMPA) was used as the chain extender. Control polyurethane biomaterial was also synthesized from hydroxy terminated polybutadiene (HTPB), dicyclohexylmethane 4,4,-diisocyanate (H12MDI) and 1,4-butane diol (BD). The resulting ion-containing polyurethanes were characterized using Fourier Transform Infrared Spectroscopy (FTIR), Nuclear Magnetic Resonance Spectroscopy (NMR) and Differential Scanning Calorimetry (DSC). These characterizations showed the successful synthesis of ion-containing polyurethanes with an improved compatibility between the two segments as observed from DSC curves. Mechanical properties of the current ion-containing polyurethanes, investigated by the tensile testing, showed higher Young’s modulus and stress at 100% strain compared with the control. Plasma protein adsorption and platelet adhesion showed that these ioncontaining polyurethanes adsorb more protein and activate more platelets than the control polyurethane. III Therefore, it is concluded that insertion of ionic groups onto the polyurethane enhances mechanical strength but results in poor blood compatibility.
Recommended Citation
Alibeik, Sara, "ION-CONTAINING POLYURETHANE BIOMATERIALS" (2006). Digitized Theses. 4941.
https://ir.lib.uwo.ca/digitizedtheses/4941