【作者】 吴峰；

【导师】 卢神州；

【作者基本信息】 苏州大学 ， 纺织工程（专业学位）， 2018， 硕士

【摘要】 作为一种组织修复材料必须要具有生物相容性以及一定的力学强度才能满足组织替代材料的要求。丝素蛋白水凝胶具有优异的生物相容性与较好的力学性能,在医学上可以用于角膜以及口腔组织的修复等方面。本文研究了两种光固化丝素蛋白水凝胶,即光固化丝素蛋白/核黄素水凝胶与光固化丝素蛋白/N-乙烯吡咯烷酮互穿网络水凝胶的制备与表征,探讨了相关凝胶机理。采用天然高分子丝素蛋白以及生物光敏剂核黄素制备光固化丝素蛋白水凝胶。核黄素在紫外光的照射下,激发生成三线态,转移生成单线态氧为主的活性氧自由基。活性氧自由基可与各种分子发生反应,诱导丝素蛋白大分子中的氨基、苯酚基以及其他基团产生化学交联,获得光固化水凝胶。研究表明光固化SF水凝胶主要以无规卷曲为主,透光性达到90%以上,压缩强度达到50k Pa以上,在压缩率达到80%的情况下,弹性回复性可以达到80%以上。其干凝胶可以再溶胀形成水凝胶,随着丝素蛋白浓度的降低,再溶胀度从400%提高到1200%,并且光固化水凝胶能够被胶原酶降解,降解速率比纯丝素水凝胶快;而细胞实验也表明该水凝胶具有良好的细胞相容性,有可能用于角膜修复材料。在此基础上,为了提高水凝胶的压缩模量,研制了光固化丝素蛋白/N-乙烯吡咯烷酮互穿网络水凝胶。通过天然高分子丝素蛋白以及N-乙烯基吡咯烷酮在辣根过氧化物酶作用下采用光聚合方法制备互穿网络丝素蛋白水凝胶。紫外光照下引发形成氧自由基,与水反应形成过氧化氢。辣根过氧化物酶催化过氧化氢形成氢氧自由基进而引发N-乙烯吡咯烷酮发生聚合反应,生成的聚合物与丝素蛋白大分子产生物理缠结从而制备得到均匀的互穿网络结构水凝胶。制得的丝素蛋白水凝胶材料具有近乎100%的透光性,压缩形变量为80%的情况下仍有高达93%以上的回弹性能,而压缩强度达到60k Pa以上。考虑到其可降解性能与良好的生物相容性,互穿网络水凝胶为丝素蛋白用于组织修复提供了一定的依据。更多还原

【Abstract】 As a tissue repair material,it must have biocompatibility and a certain degree of mechanical strength to meet the requirements of tissue replacement materials.Silk fibroin hydrogel has excellent biocompatibility and good mechanical properties,and can be used in medicine to repair cornea and oral tissues.This article focuses on the study of two photo-curable silk fibroin hydrogels,namely photo-curing silk fibroin/riboflavin hydrogels and photo-curing fibroin/N-vinyl pyrrolidone.The preparation and characterization of networked hydrogels and the related gelation mechanism were discussed.A photo-curable silk fibroin hydrogel was prepared using natural macromolecular silk fibroin and biophotosensitizer riboflavin.Riboflavin is excited by ultraviolet light to generate a triplet state,which is transferred to produce active oxygen radicals with singlet oxygen as the main component.Active oxygen radicals can react with various molecules and induce chemical cross-linking of amino groups,phenol groups,and other groups in the silk fibroin macromolecules to obtain a photocurable hydrogel.Studies have shown that light-curable SF hydrogels are mainly based on random coils,with a light transmission of over 90%,a compression strength of over 50 k Pa,and elastic recovery of over 80% when the compression rate reaches 80%.The xerogel re-swells to form a hydrogel.With a decrease in the concentration of silk fibroin,the re-swelling degree increases from 400% to 1200%,and the photo-curable hydrogel can be degraded by collagenase with a degradation rate higher than that of pure silk fibroin.Hydrogels are fast;and cell experiments have also shown that the hydrogels have good cell compatibility and may be useful for corneal repair materials.On this basis,in order to increase the compressive modulus of the hydrogel,a photo-curing silk fibroin/N-vinyl pyrrolidone interpenetrating network hydrogel was developed.An interpenetrating network silk fibroin hydrogel was prepared by photopolymerization of natural macromolecular silk fibroin and N-vinyl pyrrolidone under the action of horseradish peroxidase.The formation of oxygen radicals is initiated under UV light and reacts with water to form hydrogen peroxide.Horseradish peroxidase catalyzes the formation of hydrogen peroxide radicals by hydrogen peroxide and initiates the polymerization reaction of N-vinylpyrrolidone.The resulting polymer physically entangles with silk fibroin macromolecules to prepare a homogeneous interpenetrating network structure.glue.The obtained silk fibroin hydrogel material has nearly 100% light transmission,and when the compressive deformation is 80%,it still has repulsive energy of more than 93%,and the compressive strength reaches more than 60 k Pa.Considering its degradable properties and good biocompatibility,the interpenetrating network hydrogel provides a certain basis for the use of silk fibroin for tissue repair.更多还原