Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases 1 article published in JoVE Bioengineering 3D Microtissues for Injectable Regenerative Therapy and High-throughput Drug Screening Yaqian Li*1,2, Xiaojun Yan*1, Wei Liu*1, Lyu Zhou1,3, Zhifeng You1, Yanan Du1,2 1Department of Biomedical Engineering, School of Medicine, Tsinghua University, 2Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, 3School of Life Sciences, Tsinghua University This protocol describes the fabrication of elastic 3D macroporous microcryogels by integrating microfabrication with cryogelation technology. Upon loading with cells, 3D microtissues are generated, which can be readily injected in vivo to facilitate regenerative therapy or assembled into arrays for in vitro high-throughput drug screening.