Esworthy Timothy J, Miao Shida, Lee Se-Jun, Zhou Xuan, Cui Haitao, Zuo Yi Y, Zhang Lijie Grace
Department of Mechanical and Aerospace Engineering, The George Washington University, Washington DC 20052, USA.
Department of Mechanical Engineering, University of Hawaii at Manoa, Honolulu, HI 96822, USA.
Int J Smart Nano Mater. 2019;10(3):177-204. doi: 10.1080/19475411.2019.1631899. Epub 2019 Jul 3.
Although the process by which the cortical tissues of the brain fold has been the subject of considerable study and debate over the past few decades, a single mechanistic description of the phenomenon has yet to be fully accepted. Rather, two competing explanations of cortical folding have arisen in recent years; known as the axonal tension and the differential tangential expansion models. In the present review, these two models are introduced by analyzing the computational, theoretical, materials-based, and cell studies which have yielded them. Then Four-dimensional bioprinting is presented as a powerful technology which can not only be used to test both models of cortical folding , but can also be used to explore the reciprocal effects that folding associated mechanical stresses may have on neural development. Therein, the fabrication of "smart" tissue models which can accurately simulate the folding process and recapitulate physiologically relevant stresses are introduced. We also provide a general description of both cortical neurobiology as well as the cellular basis of cortical folding. Our discussion also entails an overview of both 3D and 4D bioprinting technologies, as well as a brief commentary on recent advancements in printed central nervous system tissue engineering.
尽管在过去几十年里，大脑皮质组织折叠的过程一直是大量研究和争论的主题，但对这一现象的单一机械描述尚未得到充分认可。相反，近年来出现了两种相互竞争的皮质折叠解释；即轴突张力模型和差异切向扩张模型。在本综述中，通过分析产生这两种模型的计算、理论、基于材料的和细胞研究来介绍这两种模型。然后介绍了四维生物打印技术，它不仅可以用于测试两种皮质折叠模型，还可以用于探索折叠相关机械应力可能对神经发育产生的相互作用。其中，介绍了能够精确模拟折叠过程并重现生理相关应力的“智能”组织模型的制造。我们还对皮质神经生物学以及皮质折叠的细胞基础进行了总体描述。我们的讨论还包括对三维和四维生物打印技术的概述，以及对打印中枢神经系统组织工程最新进展的简要评论。
