面向皮肤组织工程的水凝胶与细胞打印研究

发布时间：2018-05-01 06:14

本文选题：皮肤组织工程 + 三维打印　；参考：《浙江大学》2017年硕士论文

【摘要】：皮肤组织工程的基本原理是将体外扩增培养的皮肤种子细胞和具有优良生物相容性的材料相结合,建立细胞与生物材料之间的三维空间复合体,其基本要素包括种子细胞、支架材料和组织构建。采用生物三维打印技术能够精确定位多种类型的基质材料和细胞,具有孔隙结构可控、宽尺寸范围及高生产能力等优点,在组织工程皮肤的构建中具有极大的潜力。本学位论文采用自主研发的生物三维打印系统开展水凝胶支架与皮肤细胞的打印实验研究。在分析水凝材料基本特点的基础上,对材料挤出过程进行了计算与仿真分析。同时采用三维打印的方式进行了皮肤组织工程支架与细胞打印的实验研究,结果表明本系统具有良好的支架成型能力,构建的组织支架能够为细胞提供适宜的三维生长环境。论文主要展开的工作内容如下:一、面向皮肤组织工程的生物三维打印系统设计与研发。结合现有生物三维打印技术的基本原理与皮肤组织工程的具体要求,提出了基于气动挤出原理的柔性打印方案。系统采用独立双喷头结构,分为运动系统、供·系统、温控系统、交联系统和环境控制等五部分,可用于多种生物材料及细胞打印研究。二、水凝胶材料挤出过程分析。从幂律流体的本构方程建立了水凝胶材料从喷头挤出后的纤维宽度、支架层高及孔隙率的数学模型,并采用流体仿真的手段对材料挤出过程中的流速、壁面剪切应力、挤出胀大现象等进行了分析,为打印参数的控制优化提供了理论支持与指导。三、皮肤组织工程支架设计与打印。根据人体皮肤的结构特点设计了皮肤支架的三维模型,从多边形轮廓的特征识别、扫描求交、区域分组、路径填充等方面进行了打印算法的研究,并采用ACSPL+语言进行支架打印程序设计,最终打印出不同结构参数的三维支架结构。四、种子细胞打印与三维培养。选取皮肤成纤维细胞作为种子细胞进行细胞打印与三维培养实验研究,采用荧光染料法对打印后及培养中的细胞进行了活性分析,观察记录成纤维细胞在水凝胶三维支架中的生长、增殖及迁移情况,并进而在小鼠身上进行了皮肤损伤修复实验,取得了令人满意的修复效果。
[Abstract]:The basic principle of skin tissue engineering is to combine the expanded skin seed cells in vitro with materials with good biocompatibility to establish a three-dimensional complex between cells and biomaterials, the basic elements of which include seed cells. Scaffold materials and tissue construction. With the advantages of controllable pore structure, wide size range and high production capacity, the technology of biologic 3D printing can accurately locate many kinds of matrix materials and cells. It has great potential in the construction of tissue engineering skin. In this dissertation, the printing experiments of hydrogel scaffolds and skin cells were carried out by using the biological three-dimensional printing system developed by ourselves. Based on the analysis of the basic characteristics of the hydrated material, the extrusion process of the material was calculated and simulated. At the same time, the experiments of skin tissue engineering scaffold and cell printing were carried out by 3D printing. The results show that the system has good scaffold forming ability, and the constructed tissue scaffold can provide a suitable three-dimensional growth environment for cells. The main work of this paper is as follows: 1. Design and development of three-dimensional printing system for skin tissue engineering. A flexible printing scheme based on pneumatic extrusion principle was proposed based on the basic principle of biological 3D printing technology and the specific requirements of skin tissue engineering. The system is composed of five parts: motion system, temperature control system, cross-linking system and environmental control system. It can be used in many biomaterials and cell printing research. Second, analysis of extrusion process of hydrogel material. Based on the constitutive equation of the power law fluid, the mathematical models of the fiber width, the height of the scaffold layer and the porosity of the hydrogel material after extrusion from the nozzle are established, and the flow velocity and wall shear stress during extrusion are analyzed by means of fluid simulation. The phenomenon of extrusion swell is analyzed, which provides theoretical support and guidance for the control and optimization of printing parameters. Third, skin tissue engineering scaffold design and printing. According to the structural characteristics of human skin, the three-dimensional model of skin scaffold is designed, and the printing algorithm is studied from the aspects of polygon contour feature recognition, scanning intersection, regional grouping, path filling and so on. The ACSPL language is used to design the scaffold printing program, and finally, the 3D scaffold structure with different structure parameters is printed out. Fourth, seed cell printing and three-dimensional culture. Skin fibroblasts were selected as seed cells for cell printing and three dimensional culture. The activity of the cells after printing and in culture was analyzed by fluorescence dye method. The growth, proliferation and migration of fibroblasts in three dimensional hydrogel scaffolds were observed, and skin injury repair experiments were carried out in mice. Satisfactory results were obtained.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R318.1;TP391.73

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