In situ self-assembled organoid for osteochondral tissue regeneration with dual functional units

Zhen Yang; Bin Wang; Wei Liu; Xiaoke Li; Kaini Liang; Zejun Fan; Jiao Jiao Li; Yudi Niu; Zihao He; Hui Li; Du Wang; Jianjing Lin; Yanan Du; Jianhao Lin; Dan Xing

doi:10.1016/j.bioactmat.2023.04.002

In situ self-assembled organoid for osteochondral tissue regeneration with dual functional units

Bioact Mater. 2023 Apr 10:27:200-215. doi: 10.1016/j.bioactmat.2023.04.002. eCollection 2023 Sep.

Authors

Zhen Yang^{1

2}, Bin Wang³, Wei Liu⁴, Xiaoke Li⁵, Kaini Liang⁶, Zejun Fan⁶, Jiao Jiao Li⁷, Yudi Niu⁶, Zihao He^{1

2}, Hui Li^{1

2}, Du Wang^{1

2}, Jianjing Lin⁸, Yanan Du⁶, Jianhao Lin^{1

2}, Dan Xing^{1

2}

Affiliations

¹ Arthritis Clinical and Research Center, Peking University People's Hospital, No.11 Xizhimen South Street, Beijing, 100044, China.
² Arthritis Institute, Peking University, Beijing, 100044, China.
³ Department of Orthopedic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310006, China.
⁴ Beijing CytoNiche Biotechnology Co. Ltd, Beijing, 10081, China.
⁵ Department of Orthopedics, Shanxi Medical University Second Affiliated Hospital, Taiyuan, 030001, China.
⁶ Department of Biomedical Engineering, School of Medicine, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, 10084, China.
⁷ School of Biomedical Engineering, Faculty of Engineering and IT, University of Technology Sydney, Sydney, Australia.
⁸ Department of Sports Medicine and Rehabilitation, Peking University Shenzhen Hospital, Shenzhen, China.

Abstract

The regeneration of hierarchical osteochondral units is challenging due to difficulties in inducing spatial, directional and controllable differentiation of mesenchymal stem cells (MSCs) into cartilage and bone compartments. Emerging organoid technology offers new opportunities for osteochondral regeneration. In this study, we developed gelatin-based microcryogels customized using hyaluronic acid (HA) and hydroxyapatite (HYP), respectively for inducing cartilage and bone regeneration (denoted as CH-Microcryogels and OS-Microcryogels) through in vivo self-assembly into osteochondral organoids. The customized microcryogels showed good cytocompatibility and induced chondrogenic and osteogenic differentiation of MSCs, while also demonstrating the ability to self-assemble into osteochondral organoids with no delamination in the biphasic cartilage-bone structure. Analysis by mRNA-seq showed that CH-Microcryogels promoted chondrogenic differentiation and inhibited inflammation, while OS-Microcryogels facilitated osteogenic differentiation and suppressed the immune response, by regulating specific signaling pathways. Finally, the in vivo engraftment of pre-differentiated customized microcryogels into canine osteochondral defects resulted in the spontaneous assembly of an osteochondral unit, inducing simultaneous regeneration of both articular cartilage and subchondral bone. In conclusion, this novel approach for generating self-assembling osteochondral organoids utilizing tailor-made microcryogels presents a highly promising avenue for advancing the field of tissue engineering.

Keywords: Mesenchymal stem cells; Microcryogels; Organoid; Osteochondral regeneration; Self-assembly.