Shenzhen Key Laboratory for Psychological Healthcare and Shenzhen Institute of Mental Health 1 article published in JoVE Biology Large-Scale Preparation of Synovial Fluid Mesenchymal Stem Cell-Derived Exosomes by 3D Bioreactor Culture Li Duan1,2, Xingfu Li1,2, Xiao Xu1,2, Limei Xu1,2, Daping Wang1,2, Kan Ouyang1,2, Yujie Liang1,3 1Guangdong Provincial Research Center for Artificial Intelligence and Digital Orthopedic Technology, Shenzhen Second People's Hospital, 3Department of Child and Adolescent Psychiatry, Shenzhen Kangning Hospital, Shenzhen Mental Health Center, Shenzhen Key Laboratory for Psychological Healthcare & Shenzhen Institute of Mental Health Here, we present a protocol to produce a large number of GMP-grade exosomes from synovial fluid mesenchymal stem cells using a 3D bioreactor.