dc.description.abstract | 水凝膠是一種透過交聯而形成的親水性聚合物三維網絡,具有高度的保水能力,由於其具有高生物相容性、可調節的機械性能,被廣泛應用於生醫工程領域。然而,大部分的水凝膠無法有效防止蛋白質、細菌沾黏導致嚴重的感染與異物反應。更重要的是,水凝膠的應用很大程度受限於其機械性質的強弱與特性。為了實現抗非特異性吸附,人們開始了對各種材料的研究。雙離子材料因其優異的抗非特異性吸附能力而被視為生醫材料中非常具有潛力的材料之一。然而,其應用受限於較弱的機械強度,因此如何改善機械性質對於雙離子材料是非常重要的。在此研究中,我們以高密度的物理纏結(Entanglement)形成的物理交聯取代傳統使用交聯劑形成共價鍵的化學交聯,透過調整水凝膠聚合物網絡中的化學交聯及物理交聯實現能量逸散,使該水凝膠具有高韌性、可拉伸性、低滯後性及潤滑之特性。為了比較分子間氫鍵與網絡均勻度對高度纏結效應造成的影響,比較了四種結構之雙離子分子: Sulfobetaine methacrylate(SBMA)、Sulfobetaine acrylate(SBA)、Sulfobetaine acrylamide(SBAA)和Sulfobetaine methacrylamide(SBMAA), 透過核磁共振光譜儀(NMR)對SBA、SBMA、SBAA和SBMAA分子結構進行鑑定並進行準一級聚合反應測試(Pseudo-first-order polymerization kinetics)測試各分子結構之反應速率。並選用N,N’-Methylenebisacrylamide (MBAA)和N,N′-Methylenebismethacrylamide (MBMA)作為交聯劑,成功聚合了不同均勻度的水凝膠以動態光散射儀(Dynamic Light Scattering, DLS)分析其均勻程度,並使用萬能拉力機分析水凝膠機械性質以及其與網絡均勻度之關係。使用萬能拉力機檢測水凝膠機械性質以及滯後試驗。使用傅立葉轉換紅外線光譜儀(Fourier-Transform Infrared Spectroscopy, FTIR)、原子力顯微鏡(Atomic Force Microscope, AFM) 、客製化萬能拉力機與動態機械分析儀(Dynamic Mechanical Analyzer, DMA)分析了水凝膠結構內分子間氫鍵強度、表面吸附能與摩擦係數與黏彈特性。並透過細菌及蛋白質測試探討了高度纏結效應對抗非特異性吸附效果之影響。本論文透過比較四種分子結構探討了不同變因對高度纏結效應之影響,藉此探討如何設計出符合實際應用需求之機械性質特性之雙離子水凝膠。 | zh_TW |
dc.description.abstract | Hydrogels are three-dimensional networks of hydrophilic polymers formed through crosslinking. Owing to their high water retention capacity, high biocompatibility and controllable mechanical properties, it has extensive applications in the field of biomedical engineering. However, most of hydrogels fail to effectively prevent protein and bacterial adhesion, leading to severe infections and foreign body reactions. More importantly, the application of hydrogels is constrained by their mechanical properties, including strength and characteristics. To achieve anti-nonspecific adsorption, researchers have begun to investigate various materials. Zwitterionic materials are considered very promising materials in biomedical materials due to their excellent anti-nonspecific adsorption. However, its application is limited by weak mechanical properties. Therefore, improving mechanical properties is crucial for zwitterionic materials. In this study, we present a novel approach to overcome this limitation by preparing highly entangled zwitterionic hydrogels, which exhibit high toughness, stretchability and low hysteresis by adjusting the polymerization conditions to optimize the balance between physical and chemical cross-links through entanglements and covalent bonds, respectively to achieve energy dissipation. To compare the impact of intermolecular hydrogen bonding and network homogeneity on the highly entangled effect, four types of zwitterionic molecules were compared: Sulfobetaine methacrylate (SBMA), Sulfobetaine acrylate (SBA), Sulfobetaine acrylamide (SBAA), and Sulfobetaine methacrylamide (SBMAA). Nuclear magnetic resonance spectroscopy (NMR) was employed to identify the molecular structures of SBA, SBMA, SBAA, and SBMAA, followed by pseudo-first-order polymerization kinetics tests to measure the reaction rates of each molecular structure. We used N,N’-Methylenebisacrylamide (MBAA) and N,N′-Methylenebismethacrylamide (MBMA) as crosslinkers to successfully synthesize hydrogels with varying degrees of homogeneity. The homogeneity of hydrogels were analyzed by dynamic light scattering (DLS), while their mechanical properties were analyzed by the universal testing machine to conform the relationship between mechanical properties and network homogeneity. Mechanical properties and hysteresis were analyzed by the universal testing machine. Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), customized universal testing machines, and dynamic mechanical analysis (DMA) were employed to analyze the strength of intermolecular hydrogen bonds, surface adsorption energy, friction coefficient, viscosity and elasticity characteristic of the hydrogels. Furthermore, bacterial and protein tests were conducted to investigate the impact of the highly entangled effect on anti-nonspecific adsorption. This study compares the effects of different variables on the highly entangled effect through the analysis of four molecular structures, aiming to design zwitterionic hydrogels with mechanical properties tailored to meet practical application requirements. | en_US |