In vivo human adipose-derived mesenchymal stem cell tracking after intra-articular delivery in a rat osteoarthritis model.
Human adipose-derived mesenchymal stem cells (haMSCs) have shown efficacy in treating osteoarthritis (OA) both preclinically and clinically via intra-articular (IA) injection. However, understanding the mode of action of the cell therapy has been limited by cell tracking capability and correlation between the pharmacokinetics of the injected cells and the intended pharmacodynamics effect. This study aims to explore methodology and to understand in vivo biodistribution of clinical-grade haMSCs labeled with fluorescent dye and injected into an immunocompetent OA rat model.



haMSCs labeled with fluorescent dye were investigated for their proliferation and differentiation capabilities. Labeled cells were used to establish detection threshold of a noninvasive biofluorescent imaging system before the cells (2.5 × 106) were injected into a conventional rat OA model induced by medial meniscectomy for 8 weeks. We attempted to reveal the existence of labeled cells in vivo by imaging and a molecular biomarker approach, and to correlate with the in vivo efficacy and physical presence over a follow-up period up to 10 weeks.



In vitro proliferation and differentiation of haMSCs were not affected by the labeling of DiD dye. Detection thresholds of the labeled cells in vitro and in vivo were determined to be 104and 105cells, respectively. When 2.5 × 106haMSCs were injected into the joints of a rat OA model, fluorescent signals (or >105cells) lasted for about 10 weeks in the surgical knee joint at the same time as efficacy was observed. Signals in nonsurgical rats only lasted for 4 weeks. The human MSCs were shown to engraft to the rat joint tissues and were proliferative. Human FOXP2 gene was only detected in the knee joint tissue, suggesting limited biodistribution locally to the joints.



The current study represents the first attempt to correlate cell therapy efficacy on OA with the physical presence of the injected haMSCs in the OA model, and demonstrates that human adipose-derived mesenchymal stem cells persisted for 10 weeks locally in the rat joint, coinciding with the efficacy observed. It is postulated that persistence and/or proliferation of the haMSCs in the joint is required in order to exert their functions on promoting joint regeneration and/or cartilage protection, further supporting the safety and feasibility of IA injection of MSCs for the treatment of OA patients.
Cellular Biomedicine Group, 333 Guiping Road, Shanghai, 200233, China.|Cellular Biomedicine Group, 19925 Stevens Creek Blvd, Suite 100, Cupertino, CA, 95014, USA.
Meng
M
Li
Cellular Biomedicine Group, 333 Guiping Road, Shanghai, 200233, China.|Cellular Biomedicine Group, 19925 Stevens Creek Blvd, Suite 100, Cupertino, CA, 95014, USA.
Xuan
X
Luo
Cellular Biomedicine Group, 333 Guiping Road, Shanghai, 200233, China.|Cellular Biomedicine Group, 19925 Stevens Creek Blvd, Suite 100, Cupertino, CA, 95014, USA.
Xiaoteng
X
Lv
Cellular Biomedicine Group, 333 Guiping Road, Shanghai, 200233, China.|Cellular Biomedicine Group, 19925 Stevens Creek Blvd, Suite 100, Cupertino, CA, 95014, USA.
Victor
V
Liu
Cellular Biomedicine Group, 333 Guiping Road, Shanghai, 200233, China.|Cellular Biomedicine Group, 19925 Stevens Creek Blvd, Suite 100, Cupertino, CA, 95014, USA.
Guangyu
G
Zhao
Plastic Surgery Hospital (Institute), Peking Union Medical College, Chinese Academy of Medical Sciences, 33 Badachu Road, Shijingshan District, Beijing, 100144, China.
Xue
X
Zhang
Cellular Biomedicine Group, 333 Guiping Road, Shanghai, 200233, China.|Cellular Biomedicine Group, 19925 Stevens Creek Blvd, Suite 100, Cupertino, CA, 95014, USA.
Wei
W
Cao
Cellular Biomedicine Group, 333 Guiping Road, Shanghai, 200233, China.|Cellular Biomedicine Group, 19925 Stevens Creek Blvd, Suite 100, Cupertino, CA, 95014, USA.
Richard
R
Wang
Cellular Biomedicine Group, 333 Guiping Road, Shanghai, 200233, China. maxwell.wang@cellbiomedgroup.com.|Cellular Biomedicine Group, 19925 Stevens Creek Blvd, Suite 100, Cupertino, CA, 95014, USA. maxwell.wang@cellbiomedgroup.com.
Wen
0000-0003-3215-3020
W
Wang
D017667:Adipocytes / Q000166:cytology*; D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D049109:Cell Proliferation / Q000502:physiology; D058948:Cell Tracking / Q000379:methods; D064987:Cell- and Tissue-Based Therapy / Q000379:methods; D002478:Cells, Cultured; D004195:Disease Models, Animal; D006801:Humans; D007270:Injections, Intra-Articular / Q000379:methods; D007719:Knee Joint / Q000166:cytology; D008297:Male; D045164:Mesenchymal Stem Cell Transplantation / Q000379:methods; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D010003:Osteoarthritis / Q000628:therapy*; D051381:Rats; D012038:Regeneration / Q000502:physiology; D014018:Tissue Distribution / Q000502:physiology
Adipose-derived mesenchymal stem cells; Biodistribution; Carbocyanine dyes; Intra-articular injection; Osteoarthritis