胶原基角膜修复材料的结构仿生构建与功能化研究

发布时间：2018-08-23 12:16

【摘要】：角膜移植是目前治疗角膜病致盲唯一有效的方法，角膜修复材料的匮乏极大地限制了角膜病治疗的普及和开展本论文致力于具有较好理化性能和生物学性能的胶原基角膜修复材料的研究此外，，术后的细菌感染及炎症反应是导致角膜移植失败最主要的原因之一，因此研究在角膜修复的同时还具有广谱抗菌效果的功能化角膜修复材料也是本文的重点所在与常见的角膜修复材料相比，本文构建的结构仿生胶原基材料具有以下优点：优良的力学性能和光学性能合适的保湿性能易于营养物质透过的性能可控的孔洞和层状结构以及良好的体外和体内生物相容性等负载抗菌药物后的功能化角膜修复材料能够在一周内具有较好的抗革兰氏阴性细菌和阳性细菌的效果，并且能够较好地实现受损角膜组织的修复本文对胶原基角膜修复材料的结构仿生构建与抗菌功能化进行了深入的研究和探讨 1胶原基角膜修复材料的结构仿生构建研究角膜修复材料需要具有较为合适的理化性能和生物学性能，而这些性能与材料的结构密切相关类似于天然角膜组织的仿生结构有利于材料较好较快地实现受损组织的修复本研究采用物理或化学手段经不同的制备工艺研制出了一系列的胶原基膜材料（1）胶原-明胶-透明质酸（CGH631）复合膜材料具有较好的抗张强度亲疏水性和生物相容性，但是不能耐受手术线缝合（2）通过离子沥滤技术在胶原膜材料内部引入了纳米级的孔洞，这些微孔的存在改变了胶原膜材料的内部结构，从而提高了材料的耐缝合性能；造孔剂含量在2.5%和5.0%之间的胶原膜材料具有较为合适的理化性能和生物学性能，可以作为胶原基角膜修复材料研究的基底材料（3）通过控制高分子溶液的成膜过程构建出具有不同层状仿生结构的胶原基角膜修复材料，结果显示这些材料具有类似于天然角膜的理化性能和生物相容性，具有不同层间结构的材料能够针对角膜组织的不同部位进行替代和修复（4）通过冷冻干燥技术在结构仿生膜的基础上构建了具有微粗糙表面结构的胶原基角膜修复材料（FD-Col膜），FD-Col膜比光滑膜材料表面具有更多的蛋白吸附和细胞结合位点，角膜上皮细胞在FD-Col膜表面的上皮化过程要快于自然风干膜的光滑表面；材料在兔眼表的上皮化过程在14天内基本完成，明显快于具有光滑表面结构的材料 2胶原基角膜修复材料的抗菌功能化研究本研究创造性地通过化学交联的方法在胶原膜上负载了眼科手术中常用的光谱抗生素小分子Tobramycin，得到了能够在一周内具有药物缓释效果的抗菌功能化角膜修复材料胶原-妥布霉素膜（Col-Tob） Col-Tob膜保持了较好的光学性能，力学性能，保湿性能和生物相容性在PBS中浸泡了7天后的Col-Tob膜仍然对临床上常见的革兰氏阳性细菌金黄色葡萄球菌和阴性细菌大肠杆菌具有很好的抗菌效果人角膜上皮细胞能够较好地在Col-Tob材料表面粘附铺展生长和增殖，一周后有2~3层细胞紧密地粘合在Col-Tob膜的表面动物实验结果表明Col-Tob膜能够耐受手术线的缝合，在植入后能够较好地与剩余正常角膜组织结合，眼表没有发生细菌感染和炎症反应；术后一个月后，伤口完全愈合，眼表完成角膜上皮化过程；Col-Tob膜材料板层移植三个月后没有出现明显的新生血管和圆锥形角膜现象，起到了较好的修复效果
[Abstract]:Corneal transplantation is currently the only effective method for the treatment of corneal blindness. The lack of corneal repair materials has greatly limited the popularity of keratopathy treatment. This paper is devoted to the study of collagen-based corneal repair materials with good physical and chemical properties and biological properties. In addition, postoperative bacterial infection and inflammation are the main causes of corneal blindness. One of the main causes of graft failure is the study of functional corneal repair materials with broad-spectrum antibacterial effect.
Compared with common corneal repair materials, biomimetic collagen-based materials have the following advantages: excellent mechanical and optical properties, suitable moisture retention, easy nutrient permeability, controllable pore and layered structure, and good in vitro and in vivo biocompatibility after loading antibiotics. Corneal prosthetic materials can resist Gram-negative and positive bacteria well in one week, and can repair damaged corneal tissue. In this paper, the bionic construction of collagen-based corneal prosthetic materials and their antibacterial function were studied and discussed.
Biomimetic construction of 1 collagen based corneal repair materials
Corneal repair materials need to have more appropriate physical and chemical properties and biological properties, and these properties are closely related to the structure of materials similar to the natural corneal tissue bionic structure is conducive to better and faster repair of damaged tissues. This study developed a series of physical or chemical means through different preparation processes. Collagen-gelatin-hyaluronic acid (CGH631) composite membrane materials have good tensile strength, hydrophobicity and biocompatibility, but can not tolerate suture of surgical line (2) nano-pore was introduced into the collagen membrane materials by Ion Leaching technology, and the existence of these micropores changed the collagen membrane materials. The collagen membrane material with pore-forming agent content between 2.5% and 5.0% has better physical and chemical properties and biological properties, and can be used as the substrate material for collagen-based corneal repair materials (3) Different layered bionic junctions were constructed by controlling the film-forming process of polymer solution. The results show that these materials have similar physical and chemical properties and biocompatibility to natural corneas. The materials with different interlayer structures can be used to replace and repair different parts of corneal tissue. (4) The micro-rough surface was constructed on the basis of the Bionic Membrane by freeze-drying technology. The epithelialization process of corneal epithelial cells on the surface of FD-Col membrane was faster than that on the smooth surface of natural air-dried membrane. The epithelialization process of the materials on the surface of rabbit eyes was basically completed within 14 days, significantly faster than that on the smooth surface of natural air-dried membrane. Materials with smooth surface structure
Antibacterial function of 2 collagen based corneal repair materials
In this study, a novel antibacterial functional corneal repair material Col-Tob Col-Tob membrane was prepared by loading Tobramycin, a small spectral antibiotic commonly used in ophthalmic surgery, onto the collagen membrane by chemical cross-linking method. Col-Tob membrane still has good antibacterial effect against Gram-positive bacteria Staphylococcus aureus and negative bacterial Escherichia coli. Human corneal epithelial cells can adhere and proliferate well on the surface of Col-Tob material, and 2-3 weeks later. The results of animal experiment showed that Col-Tob membrane could tolerate the suture of surgical line, and could combine with the remaining normal corneal tissue well after implantation, and there was no bacterial infection and inflammation on the ocular surface. There was no obvious neovascularization and keratoconus after three months of lamellar transplantation of ob membranes, which had a good repair effect.
【学位授予单位】：华南理工大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：R318.08

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