Dr. Hongzhao Zhou is an Associate Professor in the School of Mechanical Engineering at Zhejiang University. His primary research focus is on additive manufacturing technology for soft materials. He explores innovative design and control techniques of complex mechatronics systems to investigate the construction of complex three-dimensional structures using soft materials. Additionally, he investigates the construction of heterogeneous tissue structures composed of living cells and bio-materials. Dr. Zhou's research outcomes have been published in several reputable journals, including Biofabrication, IEEE/ASME Transactions on Mechatronics, Additive Manufacturing, ACS Applied Materials & Interfaces, and International Journal of Extreme Manufacturing. Furthermore, Dr. Zhou serves as a Youth Editorial Board Member of Journal of Bionic Engineering, and an Academic Editor for the journal Bio-Design and Manufacturing.

Topic title: Multi-Material Embedded Printing for a Tri-Layered Artery Physiological Model

Abstract:

In order to mimic the natural heterogeneity of native tissue and provide a better micro environment for cell culturing, multi-material bioprinting is becoming a common solution to construct tissue models in vitro. With embedded printing method, complex 3D structure can be printed soft biomaterials with reasonable shape fidelity. However, the current sequential multi-material embedded printing faces a major challenge, which is the inevitable trade-off between the printed structural integrity and printing precision. Here, we propose a simultaneous multimaterial embedded printing method. With this method, we can easily print a firmly attached and high precision multilayer structure. Double layered thin-walled artery model with each layer less than 300 μm was printed, laden with smooth muscle cells and fibroblast, representing tunica media and adventitia. Subsequently, a monolayer of endothelial cells was seeded to reconstruct the tunica intima. With the proposed method, it was possible to fabricate arteries with anatomies resembling native blood vessels, resulting in improved cellular development, cellular interaction, and tissue functionalization. The interaction among the different layers of the blood vessel has been observed, as well as the vasoconstriction or relaxation as response to external stimulates.