| 摘要: | 交聯聚合物材料，特別是水凝膠和彈性體，在許多方面的應用越發廣泛，不僅在日常生活中，而且在工業和生物醫學領域也是如此。因此，具有生物降解、自我修復或可回收能力的材料對未來發展至關重要。高分子材料中的交聯劑在生物相容性、機械性能、降解性能、恢復性能和重複使用性能等方面的作用被低估了。在本論文中，我們開發了一系列的交聯劑，為共價交聯的聚合物材料提供不同的功能。
在第二章中，報告了一種創新的雙離子二甲基丙烯酸酯 2-[2-{2-(甲基丙烯醯氧基)乙基二甲基胺}乙基磷酸鹽]乙基二硫化物(MPCSS)，用於開發具有完全受生物啟發的磷酸膽鹼(PC)結構的可生物降解和生物相容性水凝膠。 MPCSS交聯劑包括提供抗汙性能的雙離子基團和可被還原劑和酶所降解的雙硫鍵。此外，MPCSS與2-甲基丙烯醯氧乙基磷酸膽鹼(MPC) 單體中的帶電基團排列相反。與使用傳統交聯劑的MPC水凝膠相比，由MPCSS和MPC所開發的水凝膠在較高的含水量和帶相反電荷的基團之間的靜電作用下具有更強的機械性能。系統性地研究了MPC/MPCSS水凝膠的生物相容性和結垢特性。此外，通過MPCSS交聯水凝膠的重量損失和流變學數據評估了其降解情況。最終，MPC/MPCSS水凝膠被證明可以原位封裝NIH-3T3纖維母細胞，並提供一個良好的三維環境，促進細胞重塑和組織支架的生長。
在第三章中，合成了三種芳香族二硫化物交聯劑，命名為SS1、SS2和SS3，以製備可自愈合和可回收的彈性體。雙硫鍵是一種可逆的共價鍵，其鍵能比碳鍵低。因此，在碳鍵斷裂之前，雙硫鍵可以被機械力劈開。這種可逆性有助於雙硫鍵的重建，為彈性體提供自我修復能力，甚至在沒有任何額外外部刺激的情況下，也能實現自我修復。此外，在SS2和SS3的情況下，將氫鍵結合至二硫化物交聯劑的結構中，可以提高彈性體在室溫下的自愈效果。在10 MPa的壓力下，12小時後自愈率可以達到100%。彈性體在被切成小塊後可以重新塑形而不降低其機械性能。 SS1、SS2和SS3交聯劑可與許多單體(包括TRIS、HEMA、HEA和BMA)一起使用，以製備具有自癒合能力的彈性體。
;Cross-linked polymer materials, especially hydrogels and elastomers, have been increasing in usage for many applications, not only in daily life but also in industry and the biomedical field. Therefore, materials with biodegradable, self-healable, or recyclable abilities are essential for future development. The role of the cross-linking agents in the polymer material was undervalued in terms of biocompatibility, mechanical properties, degradability, recovery, and reusability. In this thesis, we developed a series of cross-linker to provide different functions for the covalently cross-linked polymer materials.
In chapter two, an innovative zwitterionic dimethacrylate 2-[2-{2-(Methacryloyloxy)ethyldimethylammonium}ethyl-phosphate]ethyl disulfide (MPCSS) for the development of biodegradable and biocompatible hydrogels with entirely bio-inspired phosphocholine (PC) structure was reported. The MPCSS cross-linker includes the zwitterionic group providing nonfouling properties and a disulfide bond that can be degraded by reducing agents and enzymes. Moreover, MPCSS has an opposite arrangement of charged groups to that in the 2-methacryloyloxyethyl phosphorylcholine (MPC) monomer. The hydrogels developed from MPCSS and MPC allow stronger mechanical properties upon electrostatic interaction between the oppositely charged groups and the higher water content than the MPC gels with the conventional cross-linker. The biocompatibility and fouling characteristics of MPC/MPCSS hydrogels were systematically investigated. Moreover, the degradation of MPCSS cross-linked hydrogels was evaluated through their weight loss and rheological data. Ultimately, MPC/MPCSS hydrogel was demonstrated in situ to encapsulate NIH-3T3 fibroblasts and provide an excellent 3D environment, facilitating cell remodeling and growth as a tissue scaffold.
In chapter three, three aromatic disulfide cross-linkers, named SS1, SS2, and SS3, were synthesized to create self-healable and recyclable elastomers. The disulfide bond is a reversible covalent bond with lower bonding energy than the carbon bond. So that the SS bond can be cleft by mechanical forces before the carbon bond is broken. The reversibility helps the disulfide bond reform, providing the self-healing ability to the elastomer, even in room conditions without any extra external stimuli. Moreover, combining the hydrogen bond into the structure of the disulfide cross-linker, in the case of SS2 and SS3, can enhance the self-healing efficiency of the elastomer at room temperature. The self-healing rate can reach 100% after 12h under 10 MPa pressure. The elastomer can be remolded after being cut into small pieces without reducing mechanical properties. The SS1, SS2, and SS3 cross-linkers can be used with many monomers, including TRIS, HEMA, HEA, and BMA, to prepare the elastomers with self-healing ability. |
