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BioMed Research International
Volume 2016 (2016), Article ID 3827057, 9 pages
http://dx.doi.org/10.1155/2016/3827057
Research Article

Human Umbilical Cord Blood-Derived Mesenchymal Stem Cells Contribute to Chondrogenesis in Coculture with Chondrocytes

1Shenzhen Key Laboratory of Tissue Engineering, Shenzhen Second People’s Hospital (The First Hospital Affiliated to Shenzhen University), Shenzhen, Guangdong 518035, China
2Department of Orthopedics, Shenzhen Second People’s Hospital (The First Hospital Affiliated to Shenzhen University), Shenzhen, Guangdong 518035, China
3Department of Chemistry, The Chinese University of Hong Kong, Shatin, Hong Kong
4School of Chemical Biology & Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, Guangdong 518055, China

Received 4 February 2016; Revised 28 April 2016; Accepted 22 May 2016

Academic Editor: Subhas C. Kundu

Copyright © 2016 Xingfu Li et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) have been shown as the most potential stem cell source for articular cartilage repair. In this study, we aimed to develop a method for long-term coculture of human articular chondrocytes (hACs) and hUCB-MSCs at low density in vitro to determine if the low density of hACs could enhance the hUCB-MSC chondrogenic differentiation as well as to determine the optimal ratio of the two cell types. Also, we compared the difference between direct coculture and indirect coculture at low density. Monolayer cultures of hUCB-MSCs and hACs were investigated at different ratios, at direct cell-cell contact groups for 21 days. Compared to direct coculture, hUCB-MSCs and hACs indirect contact culture significantly increased type II collagen (COL2) and decreased type I collagen (COL1) protein expression levels. SRY-box 9 (SOX9) mRNA levels and protein expression were highest in indirect coculture. Overall, these results indicate that low density direct coculture induces fibrocartilage. However, indirect coculture in conditioned chondrocyte cell culture medium can increase expression of chondrogenic markers and induce hUCB-MSCs differentiation into mature chondrocytes. This work demonstrates that it is possible to promote chondrogenesis of hUCB-MSCs in combination with hACs, further supporting the concept of novel coculture strategies for tissue engineering.