Design and Application of a Novel Microgel-based Double Network Bioink报告人:
Deparment of Mechanical Engineering, Tsinghua University
Zhuo Xiong, Tenured Associate Professor, Deparment of Mechanical Engineering, Tsinghua University, China. Dr. Xiong served as a full-time faculty in Tsinghua University from 2001 to 2010 and was promoted to Full Professor in 2010 in the Department of Mechanical Engineering in Tsinghua University. From 2010 to 2020, he has been assigned various official administrative positions by the CPC Beijing Municipal Committee. Since 2020, he has been employed back to Tsinghua University as a Tenured Associate Professor. Dr. Xiong’s research has been on Biofabrication, 3D Bio-printing, Tissue Engineering, and 3D Cell Printing. He established his research from 3D printing to 3D bio-printing and is one of the pioneers in Biofabrication in developing low-temperature deposition manufacturing technology in 2001. Dr. Xiong has developed a variety of cell printing processes. In addition, he has also conducted a fundamental research on design and fabrication of biomimetic osteochondral and myocardial tissue constructs in vitro and in vivo. Dr. Xiong has received 6 research grants from the National Natural Science Foundation of China (NSFC). He has published over 100 peer-reviewed journal papers, 17 authorized patents, with more than 2800 citations.
Three-dimensional (3D) bioprinting has attracted great interest for its capability to precisely deposit cells and materials (i.e., bioinks) into 3D complex structures. Among various bioprinting techniques, the most common modality is extrusion bioprinting, in which a bioink needs to be extruded and then rapidly stabilized to preserve fidelity of the printed structures by digital design. A major challenge in three-dimensional (3D) extrusion bioprinting is the limited number of bioinks that fulfill the opposing requirements for printability with requisite rheological properties and for functionality with desirable microenvironment.
We address this limitation by developing a generalizable strategy for formulating microgel-based double network (M-DN) bioink. The M-DN bioink comprises two components, i.e., microgels providing excellent rheological properties for extrusion bioprinting, and a hydrogel precursor that forms an interpenetrating double network with microgels by post-printing crosslinking, facilitating the structural stability of the printed constructs. This strategy enables the effective printing of a range of hydrogels into complex structures with high shape fidelity including meniscus, nose, ears and bronchus. M-DN bioink offers great mechanical tunability without sacrificing printability, and hyperelasticity with hyper cyclic compression endurance (near-zero stress loss under 1000 compression cycles at 80% strain). The M-DN bioink preparation and printing process are highly amiable to the encapsulated cells with up to 90% viability.
Moreover, the microgels and hydrogel precursor of the M-DN bioink could be encapsulated with different types of cell, together creating a heterogeneous cellular microenvironment at the microscale level. We successfully demonstrated that hepatocytes and endothelial cells with spatial cell patterning by using M-DN bioink induced the cellular reorganization and vascularization, leading to enhanced hepatic functions. The proposed M-DN bioink expands the palette of available bioinks, and opens up numerous opportunities for the biomedical applications such as tissue engineering and soft robotics.