| 摘要: | 水凝膠是一種有潛力的生醫材料，然而，大部分的水凝膠無法有效地防止蛋白質沾黏、細胞貼附與微生物增生，導致嚴重的感染與異物體反應。除此之外，水凝膠的實際應用受限於其脆弱的機械性質。
本研究藉由加入奈米複合材料、運用互穿網絡與雙重網絡策略發展一系列堅韌的生物啟發兩性雙離子高分子水凝膠。
在第二章中，雙離子聚（磺基甜菜鹼丙烯酰胺）奈米複合水凝膠 (pSBAA/15) 具有足夠的機械性質與抗蛋白質、細菌、細胞沾黏的能力，此外，pSBAA/15水凝膠被使用為傷口敷料治療大鼠背部的一般與慢性傷口，pSBAA/15比起市售敷料具有更低的傷口沾粘，因此可以於移除敷料時減少對傷口的傷害，此外，小鼠背部的一般傷口與慢性傷口在使用pSBAA/15後第10天與12天完全癒合，癒合速度快於市售敷料，然而pSBAA/15仍然無法防止傷口感染。
在第三章中，銀奈米粒子被還原並形成於雙離子聚（磺基甜菜鹼丙烯酰胺）奈米複合水凝膠中 (pSBAA/Ag15)，銀離子釋放率可以被奈米黏土有效控制，因此pSBAA/Ag15對人類纖維母細胞的細胞毒性微不足道。同時，pSBAA/Ag15具有明顯的抑菌圈，顯示出強大的殺菌能力。在動物實驗中，大鼠背部的細菌感染慢性傷口在使用pSBAA/Ag15水凝膠後第15天傷口達到完全上皮化，顯示出pSBAA/Ag15水凝膠對治療細菌感染的慢性傷口有巨大優勢。
在第四章中，鹽響應互穿型水凝膠 (pTMAEMA/pSBVI)經由光聚合將鬆散交聯的雙離子聚（磺基甜菜鹼乙烯基咪唑）(pSBVI)網絡形成於高度交聯的陽離子聚甲基丙烯酸三（三甲氨基）乙酯氯化物網絡中 (pTMAEMA)，由於聚電解質效應與反聚電解質效應，陽離子pTMAEMA與雙離子pSBVI在鹽溶液中展現相反的澎潤行為，因此，pTMAEMA/pSBVI水凝膠展現一系列離子強度可控的總體性質與介面特性，包含機械性質、光學性質、表面摩擦、表面電性、殺菌性質、與表面再生。
在第五章中，我們展示一種全新的方法經由響應性的兩性聚合物作為框架，合成完全生物相容性雙層網絡水凝膠。完全雙離子雙層網絡水凝膠(PLysAA/PSBAA)經由光聚合將聚（磺基甜菜鹼丙烯酰胺）(PSBAA)網絡形成在酸性或鹼性中澎潤的聚賴氨酸丙烯酰胺(PLysAA)網絡中。在生理條件下，雙層網絡水凝膠變成完全的雙離子水凝膠。pLysAA/PSBAA的機械性質可與傳統的雙層網絡水凝膠匹配，除此之外，PLysAA/PSBAA在接觸全血後幾乎沒有血栓形成，展現優異的生物相容性。此外，PLysAA/PSBAA水凝膠在大鼠的皮下植入中可抵抗發炎反應與長期膠囊形成。
強韌的雙離子水凝膠展現高的機械性質與良好的生物相容性，具有高度的潛力用於實際的生物醫學應用。
;Hydrogels have regarded as promising biomaterials. However, most hydrogels cannot effectively resist protein adsorption, cell adhesion and microorganism growth, leading to serious infection, and foreign body reaction. Moreover, the weak mechanical properties of hydrogel also limited further application in the real world.
In this thesis, we developed a series of tough zwitterionic hydrogel by the addition of nanocomposite materials, interpenetrating networks, and double network strategies.
In chapter II, the zwitterionic poly(sulfobetaine acrylamide) nanocomposite hydrogels (pSBAA/15) have sufficient mechanical properties and good resistance against the protein, bacteria, and cell adsorption. Moreover, the pSBAA/15 hydrogel was used as a wound dressing to heal the normal wound and diabetic wound in the mice model. Comparing to the commercial dressing, the pSBAA/15 hydrogel showed a low adhesion against the wound surface, leading to the minimization of wound damage when removal of the wound dressing. Furthermore, the pSBAA/15 hydrogels were covered on normal and diabetic wounds on rat dorsal and showed a complete heal after 10 and 12 days, respectively, which was faster than commercial dressings. However, the pSBAA/15 still cannot prevent the bacteria infection on the chronic wound.
In chapter III, the silver nanoparticles were reduced and formed within the pSBAA/Ag15 hydrogels. The release rate of silver ions can be effectively controlled in the presence of the nanoclay, resulting in the negligible cytotoxicity of pSBAA/Ag15 hydrogel against human fibroblasts. Meanwhile, the pSBAA/Ag15 hydrogel showed strong antimicrobial properties by obvious inhibition of zone. In vivo experiment, the infected chronic wound on rat dorsal was complete epithelialization after 15 days with the treatment of pSBAA/Ag15. The finding indicated the great benefits of pSBAA/Ag15 for the treatment of infected chronic wounds.
In chapter IV, a salt-responsive interpenetrating network (IPN) hydrogel was engineered using the double network strategy to form loosely cross-linked zwitterionic poly(sulfobetaine vinylimidazole) (pSBVI) networks into the highly cross-linked cationic poly((trimethylamino)ethyl methacrylate chloride) (pTMAEMA) framework via photo-polymerization. The cationic pTMAEMA and zwitterionic pSBVI show opposite swelling behaviors in salt solutions due to the polyelectrolyte effect and antipolyelectrolyte effect. To this end, the pTMAEMA/pSBVI hydrogels demonstrated a series of switchable bulk and interfacial properties, including mechanical properties, optical properties, surface friction, surface charge, antimicrobial properties, and surface regeneration in response to ionic strength.
In chapter V, we demonstrated a new methodology for developing fully biocompatible double network (DN) hydrogels via using a responsive amphoteric polymer as a first framework. Whole zwitterionic DN hydrogels were synthesized by penetrating and photo-polymerizing zwitterionic poly(sulfobetaine acrylamide) (PSBAA) into a swelled amino-acid based poly(lysine acrylamide) (PLysAA) first network in an acidic or basic solution. Under a physiological condition, the DN hydrogels become fully zwitterionic. The mechanical properties of pLysAA/pSBAA hydrogel were comparable to conventional DN hydrogels. Additionally, the superior biocompatibility of the zwitterionic DN hydrogels displayed negligible thrombus formation after contacting whole blood. Furthermore, PLysAA/PSBAA hydrogels were implanted subcutaneously, showing excellent resistance against inflammatory response and long-term capsule formation.
The tough zwitterionic hydrogels showed high mechanical properties and good biocompatibility, which have a high potential for real-world biomedical applications. |
