Affiliations: Groupe Ingénierie Cellulaire et Tissulaire, UMR7563 CNRS-UHP-INPL LEMTA et IFR 111, Faculté de Médecine, 54505 Vandoeuvre-lès-Nancy, France | Department of Biochemistry and Molecular Biology, School of Medicine, Wuhan University, 430071 Wuhan, P. R. China | Laboratoire de Physiopathologie et Pharmacologie Articulaires, UMR7561 CNRS-UHP, Faculté de Médecine, 54505 Vandoeuvre-lès-Nancy, France | CHU–UTCT–Brabois, 54500 Vandoeuvre-lès-Nancy, France
Note: [] Address for correspondence: J.F. Stoltz, Groupe Mécanique Ingénierie Cellulaire et Tissulaire, UMR7563 CNRS-UHP-INPL LEMTA et IFR 111, Faculté de Médecine, 54505 Vandoeuvre-lès-Nancy, France. Tel.: +33 03 83683452; Fax: +33 03 83683459; E-mail: jf.stoltz@chu-nancy.fr.
Abstract: To investigate whether the chondrocytes–alginate construct properties, such as cell seeding density and alginate concentration might affect the redifferentiation, dedifferentiated rat articular chondrocytes were encapsulated at low density (LD: 3×106 cells/ml) or high density (HD: 10×106 cells/ml) in two different concentrations of alginate gel (1.2% or 2%, w/v) to induce redifferentiation. Cell viability and cell proliferation of LD culture was higher than those of HD culture. The increase in alginate gel concentration did not make an obvious difference in cell viability, but reduced cell proliferation rate accompanied with the decrease of cell population in S phase and G2/M phase. Scan electron microscopy observation revealed that chondrocytes maintained round in shape and several direct cell–cell contacts were noted in HD culture. In addition, more extracellular matrix was observed in the pericellular region of chondrocytes in 2% alginate culture than those in 1.2% alginate culture. The same tendency was found for the synthesis of collagen type II. No noticeable expression of collagen type I was detected in all constructs at the end of 28-day cultures. These results suggested that construct properties play an important role in the process of chondrocytes' redifferentiation and should be considered for creating of an appropriate engineered articular cartilage.
