基于荧光图像的水凝胶几何网格重建及其力学性能有限元的模拟  

Reconstruction of hydrogel geometric network based on fluorescent images and finite element simulation of its mechanical properties

作　　者：吴少东 朱思勉 曾柱 WU Shaodong;ZHU Simian;ZENG Zhu(School of Biology and Engineering,Guizhou Medical University&Key Laboratory of Infectious Immune and Antibody Engineering of Guizhou Province&Engineering Research Center of Cellular Immunotherapy of Guizhou Province,Guiyang 550025,Guizhou,China;Key Laboratory of Biology and Medical Engineering,Guizhou Medical University&Immune Cells and Antibody Engineering Research Center of Guizhou Province,Guiyang 550025,Guizhou,China)

机构地区：[1]贵州医科大学生物与工程学院&贵州省感染免疫与抗体工程特色重点实验室&贵州省细胞免疫治疗工程研究中心,贵州贵阳550025 [2]贵州医科大学生物与医学工程重点实验室&贵州省免疫细胞与抗体工程研究中心,贵州贵阳550025

出　　处：《贵州医科大学学报》2024年第11期1577-1586,共10页Journal of Guizhou Medical University

基　　金：国家自然科学基金(12132006)。

摘　　要：目的探讨通过荧光图像重建水凝胶的几何网络及其用于有限元模拟的可行性。方法取冷水鱼皮的明胶水溶液,分别与28.2、56.5、113.0、141.0 mg戊二醛交联16 h,制备明胶水凝胶;采用动态热机械分析技术测量各组明胶水凝胶的力学性能,并计算压缩模量(Emeas),用激光共聚焦显微镜和图像分割程序分析观测各组明胶水凝胶的孔隙结构;采用图像分割及行进立方体算法进行各组水凝胶支架几何模型的三维重建,对水凝胶荧光图像进行预处理、分割、重建及优化;采用ANSYS Workbench计算有限元,使用静态结构分析模拟各组水凝胶的压缩试验,计算模拟得到模型的压缩模量(Esim)以及水凝胶结构的负载情况。结果动态热机械分析获得水凝胶的应力应变数据,计算得到Emeas分别为(457.0±30.8)、(942.7±260.5)、(2053.3±115.0)及(2133.3±125.8)Pa;观测到经戊二醛交联的水凝胶孔隙发生变化,且戊二醛浓度越高,水凝胶的孔径越小、孔数量越多;三维重建程序生成了可用于有限元体网格划分的水凝胶几何模型;有限元模拟计算得到的Esim与Emeas一致,分别为447.2、829.9、1987.7及2181.6 Pa;有限元模拟结果显示,水凝胶结构承担的载荷增加,与基体相比,纤维网络承担主要载荷且载荷增加量更大;当基体弹性模量增加,纤维网络与基体界面处的应力分布的不均匀性降低,与纤维网络相比,基体共享负载增加。结论利用三维重建方法构建了水凝胶几何模型,模拟的有限元模型可反映明胶水凝胶的力学性能。Objective To investigate the feasibility of reconstructing the geometric network of hydrogels from fluorescent images and its feasibility of finite element modeling.Method Gelatin hydrogels were prepared from a cold-water fish skin gelatin aqueous solution,cross-linked with 28.2,56.5,113.0,and 141.0 mg of glutaraldehyde for 16 hours.The mechanical properties of each group of gelatin hydrogels were measured using dynamic mechanical analysis,and the compressive modulus(E meas)was calculated.The pore structures of each group of gelatin hydrogels were observed and analyzed using laser confocal microscopy and image segmentation programs.Three-dimensional reconstruction of the hydrogel scaffold geometric models was performed using image segmentation and the marching cubes algorithm.The fluorescent images of the hydrogels were pre-processed,segmented,reconstructed,and optimized.Finite element analysis was conducted using ANSYS Workbench,employing static structural analysis to simulate the compression tests of each group of hydrogels.The compressive modulus(E sim)and load distribution of the hydrogel structures were calculated from the simulations.Results Dynamic mechanical analysis provided stress-strain data for the hydrogels,yielding E meas values of(457.0±30.8)Pa,(942.7±260.5)Pa,(2053.3±115.0)Pa,and(2133.3±125.8)Pa.Observations indicated that the pore structure of the glutaraldehyde-crosslinked hydrogels changed,with higher glutaraldehyde concentrations resulting in smaller pore sizes and increased pore numbers.The 3 D reconstruction program generated geometric models of the hydrogels suitable for finite element meshing.The finite element simulation results for E sim were consistent with E meas,producing values of 447.2 Pa,829.9 Pa,1987.7 Pa,and 2,181.6 Pa,respectively.The finite element analysis indicated that the load-bearing capacity of the hydrogel structure increased,with the fiber network bearing a greater proportion of the load compared to the matrix.As the elastic modulus of the matrix increased,the stres

关 键 词：有限元分析 水凝胶 生物力学现象 图像分割 三维重建 力学分析 

分 类 号：R318[医药卫生—生物医学工程]