Rosellini Elisabetta, Vozzi Giovanni, Barbani Niccoletta, Giusti Paolo, Cristallini Caterina
Department of Chemical Engineering, Industrial Chemistry and Materials Science, University of Pisa, Pisa, Italy.
Int J Artif Organs. 2010 Dec;33(12):885-94.
In recent years, research in the field of myocardial tissue engineering has advanced thanks to the development of new biomaterials and a more clear understanding of processes that are at the basis of cardiac tissue growth. However, classical porous scaffolds developed during these years to try to reconstruct and mimic heart function have proven to be inadequate because they are not able to reproduce the typical myocardial environment. One approach to increase functionality of tissue-engineered constructs relies on attempts to mimic the microarchitecture of natural tissues, since it is well known that topology is one of the principal stimuli that cells need to activate their functions. The aim of this work was the realization of three-dimensional microfabricated scaffolds, with cardiac extracellular matrix (ECM)-like architecture. For this purpose, samples of pig myocardium were decellularized, embedded in paraffin wax and analyzed under an optical microscope, in order to evaluate the geometrical features of the cardiac ECM. On the basis of these data, a simplified model of the cardiac ECM microarchitecture was designed. Microfabricated scaffolds were realized with Soft Lithography technique, using a bioartificial blend, based on alginate, gelatin and a novel poly(N-isopropylacrylamide)-based copolymer, which we synthesized. The scaffolds were characterized in terms of topological and mechanical properties. Moreover, cell adhesion, proliferation, and differentiation tests were performed. The microfabricated scaffolds showed they matched the anisotropic mechanical properties of adult human left ventricular myocardium, while at the same time being able to promote myoblast alignment in the absence of external stimuli.
近年来，由于新型生物材料的开发以及对心脏组织生长基础过程的更清晰理解，心肌组织工程领域的研究取得了进展。然而，这些年来开发的用于尝试重建和模拟心脏功能的经典多孔支架已被证明是不够的，因为它们无法重现典型的心肌环境。增加组织工程构建体功能的一种方法是尝试模仿天然组织的微观结构，因为众所周知，拓扑结构是细胞激活其功能所需的主要刺激因素之一。这项工作的目的是实现具有类似心脏细胞外基质（ECM）结构的三维微制造支架。为此，将猪心肌样本进行脱细胞处理，嵌入石蜡中并在光学显微镜下进行分析，以评估心脏ECM的几何特征。基于这些数据，设计了心脏ECM微观结构的简化模型。使用基于藻酸盐、明胶和我们合成的新型聚（N-异丙基丙烯酰胺）基共聚物的生物人工混合物，通过软光刻技术实现了微制造支架。对支架的拓扑和力学性能进行了表征。此外，还进行了细胞粘附、增殖和分化测试。微制造支架显示出它们与成人左心室心肌的各向异性力学性能相匹配，同时能够在没有外部刺激的情况下促进成肌细胞排列。
