The Effect of Micro-Phase Separation on the Biocompatibility of Biomedical Grade Poly(carbonate)urethanes

• Main Authors: YuChih Kao, 高有志
• Other Authors: 徐善慧
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/85594183075902873188

碩士 === 國立中興大學 === 化學工程學系 === 90 === This study intended to establish the relationship between the micro-phase separation of poly(carbonate)urethanes (PCU) and their biocompatilibity. Seven different poly(carbonate)urethanes with different stoichiometries were synthesized using the same isocyanate, polycarbonate diol and chain extender, which were 4,4’-diphenylmethane diisocyanate (MDI), poly (hexyl, ethyl) carbonate diol (PC diol) and 2-butene-1,4-diol (BDO) respectively. The study was conducted in two parts. In the first part, we analyzed the physical and chemical properties of PCU. The micro-phase separation of PCU was evaluated by AFM (atomic force microscopy) and DMA (dynamic mechanical analysis). We investigated the correlation between the properties of micro-phase separation and the biocompatibility including endothelial cell proliferation, platelet activation, and macrophage formation. To further explore the underlying principle, adsorption behavior of human plasma albumin and fibrinogen on PCU was analyzed. In the second part, the effects of storage time and water environment on the micro-phase separation of PCU were examined. We also blended Pellethane 2363-80A and PCU to see if the mechanical properties of PCU could be improved. We found the reaction time for chain extender and catalyst would affect the molecular weight distribution. DMA and AFM could be used in quantitative and qualitative analyses of the micro-phase separation properties of poly(carbonate) urethanes. The characteristic forces within the micro-domain structures varied with different contents of soft segment. The micro-structures revealed phase-mixing or phase-separation domains. The glassy transition temperatures of PCU were changed by different reagent stoichiometries that further resulted in different micro-phase separation. Micro-phase separation or micro-phase mixing domains would affect the biocompatibilities. Greater micro-phase separation resulted in better endothelial cell growth, less platelet activation, less macrophage formation, and smaller fibrinogen versus albumin adsorption ratio. Both the surface domain sizes (resulted from the micro-phase separation) and plasma protein sizes would affect the protein adsorption on the PCU. The storage time after film cast altered the attractive forces between molecular chains of PCU. In conclusion, poly(carbonate)urethanes with larger micro-phase separation structures had better biocompatibility and were suitable for cardiovascular applications.