Glucosamine Hydrochloride and N-Acetylglucosamine Influence the Response of Bovine Chondrocytes to TGF-β3 and IGF in Monolayer and Three-Dimensional Tissue Culture

BACKGROUND: Glucosamine hydrochloride (GlcN·HCl) has been shown to inhibit cell growth and matrix synthesis, but not with N-acetyl-glucosamine (GlcNAc) supplementation. This effect might be related to an inhibition of critical growth factors (GF), or to a different metabolization of the two glucosamine derivatives. The aim of the present study was to evaluate the synergy between GlcN·HCl, GlcNAc, and GF on proliferation and cartilage matrix synthesis. METHOD: Bovine chondrocytes were cultivated in monolayers for 48 h and in three-dimensional (3D) chitosan scaffolds for 30 days in perfusion bioreactors. Serum-free (SF) medium was supplemented with either growth factors (GF) TGF-β (5 ng mL₋₁) and IGF-I (10 ng mL₋₁), GlcN·HCl or GlcNAc at 1mM each or both. Six groups were compared according to medium supplementation: (a) SF control; (b) SF + GlcN·HCl; (c) SF + GlcNAc; (d) SF + GF; (e) SF + GF + GlcN·HCl; and (f) SF + GF + GlcNAc. Cell proliferation, proteoglycan, collagen I (COL1), and collagen II (COL2) synthesis were evaluated. RESULTS: The two glucosamines showed opposite effects in monolayer culture: GlcN·HCl significantly reduced proliferation and GlcNAc significantly augmented cellular metabolism. In the 30 days 3D culture, the GlcN·HCl added to GF stimulated cell proliferation more than when compared to GF only, but the proteoglycan synthesis was smaller than GF. However, GlcNAc added to GF improved the cell proliferation and proteoglycan synthesis more than when compared to GF and GF/GlcN·HCl. The synthesis of COL1 and COL2 was observed in all groups containing GF. CONCLUSION: GlcN·HCl and GlcNAc increased cell growth and stimulated COL2 synthesis in long-time 3D culture. However, only GlcNAc added to GF improved proteoglycan synthesis.

Cartilage Engineering Using Fibrin Gel and Chondrocyte Cell Sheets / 中山大学学报(医学科学版)

Objective]To study the feasibility of Cartilage engineering using fibrin gel and chondrocyte cell sheets.[Methods]rabbit auricular chondrocytes were isolated and cultured to form cell sheets in flasks. The cell sheets were harvested using cell scrapers,and cut into fragments. The two precursor solutions of Fibrin gel were used to suspend the cell sheet fragments and isolated chondrocytes,and then added into the wells of a 48-well plate to form Gelatinous chondroid disc constructs. After in vitro culture, the constructs were implanted into nude mice. After 8 weeks,the constructs were harvested,and the specimens were evaluated using grossly observing, histological and immunohistochemical observation. [Results]Mature cartilage discs were obtained. The histomorphology of the explanted discs appeared non-uniform cartilaginous tissue comprise of regenerated cartilage islands with different size and irregular shape. Immunohistochemistry staining demonstrated that type II collagen highly expressed in the ECM of the cartilage islands. In 1 of the 8 discs,partial ossification was observed.[Conclusion]Fibrin gel is a favourable carrier. Artificial cartilage with stereochemical structure was constructed via combining the fibrin gel and chondrocyte cell sheets.

Porous Microcarrier-Enabled Three-Dimensional Culture of Chondrocytes for Cartilage Engineering: A Feasibility Study

Cartilage repair is substantially intractable due to poor self-healing ability. Porous microspheres can be a fascinating three-dimensional matrix for cell culture and injectable carrier in cartilage engineering. In this study, we assessed the feasible use of porous biopolymer microspheres for chondrocyte carriers. When seeded onto the blended biopolymer microspheres and followed by a dynamic spinner flask culture, the chondrocytes showed robust growth behaviors during the culture period. The gene expressions of SOX9, type II collagen, and aggrecan were significantly upregulated after 2-week of culture. Furthermore, immunolocalization of type II collagen and secretion of glycosaminolglycan became prominent. The results suggest the feasible usefulness of the porous microspheres as the cell culture matrix and the subsequent delivery into cartilage defects.