机械转导

Abstract(#br)Cell–extracellular matrix (ECM) interactions play a critical role in regulating cellular behaviors. Recent studies of cell–ECM interactions have mainly focused on the actomyosin based and adhesion mediated mechanosensing pathways to understand how individual mechanical signals in the cell microenvironment, such as matrix rigidity and adhesive ECM pattern, are sensed by the cell and further trigger downstream intracellular signaling cascades and cellular responses.

Abstract(#br)In this article we demonstrate the effect of mechanical compression on the behavior of cultured neural stem cells using a microelectromechanical system platform. Polydimethylsiloxane (PDMS)-based stretchable substrates were used on a neurosphere (NS) assay to investigate the role of mechanical forces on the formation of radial glial processes and neuronal migration. To induce mechanical compression on NS, the PDMS culturing substrate was patterned with micron-sized wells. NS were cultured on the prestretched device.

Abstract(#br)A platform for the batch fabrication of pneumatically actuated Stretchable Micro-Electrode Arrays (SMEAs) by using state-of-the-art micro-fabrication techniques and materials is demonstrated. The proposed fabrication process avoids the problems normally associated with processing of thin film structures on polydimethylsiloxane (PDMS), by first fabricating the electrodes and electrical interconnects on the silicon wafer using fine-pitched stepper lithography, and afterwards transferring the structures to the elastomer.

Abstract(#br)Mechanics of the extracellular matrix (ECM) play a pivotal role in governing cell behavior, such as cell spreading and differentiation. ECM mechanics have been recapitulated primarily in elastic hydrogels, including with dynamic properties to mimic complex behaviors (e.g., fibrosis); however, these dynamic hydrogels fail to introduce the viscoelastic nature of many tissues.

Mechanobiology is a rapidly growing interdisciplinary research field, involving biophysics, molecular and cell biology, biomedical engineering, and medicine. Rapid progress has been possible due to emerging devices and tools engineered for studies of the effect of mechanical forces, such as stretch or shear force, impacting on biological cells and tissues.

近十几年来，水凝胶由于具有生物相容性、可降解性以及广泛可调的力学性能，在体外模拟三维( 3D )脑结构方面显示了巨大的潜力。为了更好地理解体外人脑模型和力学传导过程，我们根据我们在微型聚二甲基硅氧烷( PDMS )环中的经验，将光聚合明胶甲基丙烯酰基( GelMA )与聚丙烯酸乙二醇酯( PEGDA )相比较，制备了三维水凝胶模型。3D SH - SY5Y神经母细胞瘤细胞在GelMA中呈长条状、分枝状和铺展状，类似神经元，而在铸型PEGDA中细胞存活不受支持。共聚焦z-stack显微镜证实了我们的假设，即硬到软的物质转变促进了神经元向第三维的迁移。不幸的是，也观察到大的细胞集合体。随后的细胞播种密度研究发现，播种密度在1万个/ cm2以上开始形成细胞集合体，低于1500个/ cm2的细胞在第6天仍以单细胞形式出现。结果表明，最佳的细胞接种密度为1500 - 5000cells / cm2，该水凝胶结构适合于设计更先进的三维微流控芯片脑机械传递模型。

近十几年来，水凝胶由于具有生物相容性、可降解性以及广泛可调的力学性能，在体外模拟三维( 3D )脑结构方面显示了巨大的潜力。为了更好地理解体外人脑模型和力学传导过程，我们根据我们在微型聚二甲基硅氧烷( PDMS )环中的经验，将光聚合明胶甲基丙烯酰基( GelMA )与聚丙烯酸乙二醇酯( PEGDA )相比较，制备了三维水凝胶模型。3D SH - SY5Y神经母细胞瘤细胞在GelMA中呈长条状、分枝状和铺展状，类似神经元，而在铸型PEGDA中细胞存活不受支持。共聚焦z-stack显微镜证实了我们的假设，即硬到软的物质转变促进了神经元向第三维的迁移。不幸的是，也观察到大的细胞集合体。随后的细胞播种密度研究发现，播种密度在1万个/ cm2以上开始形成细胞集合体，低于1500个/ cm2的细胞在第6天仍以单细胞形式出现。结果表明，最佳的细胞接种密度为1500 - 5000cells / cm2，该水凝胶结构适合于设计更先进的三维微流控芯片脑机械传递模型。