表面改性静电纺丝PCU支架用于小口径血管的研究

发布时间：2018-07-09 11:42

本文选题：静电纺丝 + 聚碳酸酯聚氨酯　；参考：《天津大学》2013年硕士论文

【摘要】：随着组织工程的发展，发挥静电纺丝技术的独特优势，，制备具有合适物理机械性能的仿生支架作为小口径血管成为研究热点。本文利用静电纺丝技术制备聚碳酸酯聚氨酯三维纤维小孔径血管支架，并通过聚合接枝改性方法对支架的表面进行了改性，使其具有良好的生物相容性以用作小口径血管支架。首先利用静电纺丝技术制备了形貌结构良好的PCU纤维支架，为了改善PCU疏水性的缺点，利用表面引发原子转移自由基聚合(SI-ATRP)方法在纤维表面接枝亲水性材料聚乙二醇甲基丙烯酸酯(PEGMA)，并设计了由控制单体的投入量来控制链段的长度，并探究了链段长度对改性效果的影响。为了提高PCU纤维支架表面的生物形容性，本文又利用戊二醛交联接枝方法将明胶这一天然生物蛋白质高分子引入到了纤维表面，并将PEGMA作为中间臂，将其羟基位点转化为接枝明胶活性位点，放大了明胶的接枝密度，并进一步比较探讨了明胶接枝量对其改性效果的影响。采用SEM观察改性过程对电纺丝骨架结构形貌的影响；通过水接触角实验来表征支架表面的亲水性能；利用傅里叶红外光谱(FT-IR)、X射线光电子能谱(XPS)检测方法，表征改性前后样品的化学性质的变化，从化学组成角度表征改性过程对材料表面性质的影响；利用血小板吸附实验、溶血测试和活化部分凝血酶时间(APTT)测试，表征改性样品血液相容性的变化；通过接种培养脐静脉内皮细胞来表征改性支架的细胞相容性。实验结果表明各种改性方法在均没有破坏电纺血管支架的骨架结构，并有效地改善了支架的血液相容性和生物相容性。与改性前相比，改性支架表面的亲水性得到了明显改善，且能有效抑制血小板粘附，溶血率也有所降低，APTT时间有所延长，表明改性支架具有良好的血液相容性。内皮细胞在改性后支架表面粘附、生长、增殖良好，能在表面形成单层细胞层。通过研究，本文改性的电纺支架为作为小口径血管提供了可能。
[Abstract]:With the development of tissue engineering, the preparation of bionic scaffolds with suitable physical and mechanical properties as small diameter vessels has become a research hotspot. In this paper, polycarbonate polyurethane three-dimensional fiber scaffolds with small pore diameter were prepared by electrospinning technique. The surface of the scaffolds was modified by polymerization and graft modification, which made them have good biocompatibility to be used as small diameter vascular scaffolds. In order to improve the hydrophobicity of PCU, PCU fiber scaffolds with good morphology and structure were prepared by electrostatic spinning. Surface initiated atom transfer radical polymerization (SI-ATRP) was used to graft the hydrophilic polyethylene glycol methacrylate (PEGMA) onto the fiber surface, and the length of the chain was controlled by controlling the amount of monomer input. The effect of chain length on the modification effect was also investigated. In order to improve the biological description of the surface of PCU fiber scaffold, gelatin, a natural biological protein polymer, was introduced into the fiber surface by glutaraldehyde crosslinking grafting method, and PEGMA was used as the intermediate arm. The hydroxyl site was transformed into the active site of grafted gelatin, the grafting density of gelatin was enlarged, and the effect of the amount of gelatin graft on the modification effect was discussed. SEM was used to observe the influence of the modification process on the morphology of the electrospinning skeleton structure, the hydrophilicity of the scaffold surface was characterized by water contact angle experiment, and the X-ray photoelectron spectroscopy (XPS) method was used to detect the structure of the scaffold by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The changes of the chemical properties of the samples before and after modification were characterized, and the effects of the modification process on the surface properties of the materials were characterized from the perspective of chemical composition, and the platelet adsorption test, hemolysis test and activated partial thrombin time (APTT) test were used. The changes of blood compatibility of the modified scaffolds were characterized by inoculation of umbilical vein endothelial cells (HUVEC) to characterize the cytocompatibility of the modified scaffolds. The experimental results show that all kinds of modification methods do not destroy the skeleton structure of electrospun vascular scaffolds and improve the blood compatibility and biocompatibility of the scaffolds effectively. Compared with before modification, the hydrophilicity of the modified scaffold was obviously improved, and the platelet adhesion was effectively inhibited, and the hemolysis rate was also decreased. The results showed that the modified scaffold had good blood compatibility. Endothelial cells adhered, grew and proliferated well on the surface of the scaffold, and formed monolayer cell layer on the surface. Through the research, the modified electrospinning scaffold provides the possibility for the small diameter blood vessel.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R318.08

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