In vivo chondrogenesis by co-culture of rabbit bone marrow-derived mesenchymal stem cells and chondrocytes

Yunfeng NI; Xiaofei LI; Yuan LIU; Zhanjun LEI; Qiang LU

ABSTRACT

BACKGROUND:

Inducing factor and chondrogenic microenvironment is a primary factor, which influences chondrogenic differentiation and chondrogenesis of bone marrow-derived mesenchymal stem cells (MSCs).

OBJECTIVE:

To explore the feasibility of in vivo chondrogenesis by co-culture of bone marrow-derived MSCs and chondrocytes. DESIGN, TIME AND

SETTING:

A randomized controlled animal experiment was performed at Department of Pathology, Stomatological Hospital, Fourth Military Medical University of Chinese PLA between September 2004 and March 2005. MATERIALSFifteen New Zealand rabbits of clean grade were used for cell-scaffold construct transplantation. The rabbits were randomly divided into co-culture, chondrocyte, and bone marrow-derived MSC groups, with 5 rabbits in each group. Five neonatal New Zealand rabbits, aged 1-3 days, were used for isolation and culture of bone marrow-derived MSCs and chondrocytes. Polyglycolic acid (PGA) scaffold material (Shanghai Yikuo Company, China) has a fiber diameter of 15 μm, with an average interval of 150-200 μm, an interval porosity of 97% and 2-mm thickness.

METHODS:

In the co-culture group, bone marrow-derived MSCs and chondrocytes were mixed at a ratio of 31. The mixed cells were seeded onto a pre-wetted PGA scaffold (5 mm×5 mm )at the ultimate concentration of 6.0×1010 L-1. Dulbecco's modified Eagle's medium (DMEM) supplemented with fetal bovine serum was dropwise added to peripheral compound for 1 week of culture. In the chondrocyte, and bone marrow-derived MSC groups, chondrocytes and bone marrow-derived MSCs of the same ultimate concentration were seeded respectively onto the PGA scaffold. Then, the cell-scaffold constructs were transplanted into subcutaneous tissue of adult rabbits. MAIN OUTCOME

MEASURES:

Gross observation and hematoxylin-eosin & Masson staining of neo-cartilage were performed after in vivo culture for 8 weeks.

RESULTS:

Cell in all groups had a fine adhesion to the scaffold. In both co-culture and chondrocyte groups, the cell-scaffold constructs could maintain the original size and shape during in vivo culture and formed homogenous mature cartilage after 8 weeks of in vivo culture. Furthermore, the neo-cartilages in both groups were similar to each other in gross appearance and histological features. In the bone marrow-derived MSCs group, connective tissue rather than cartilage was found during in vivo culture.

CONCLUSION:

Chondrocytes can provide a chondrogenic microenvironment to induce a chondrogenic differentiation of bone marrow-derived MSCs and thus promote the chondrogenesis of bone marrow-derived MSCs in vivo.