[Tissue engineered cartilage using chitosan/gelatin and normal or post-RNA interference-chondrocytes in vitro]

The seed cells source is a research focus in tissue engineered cartilage. To observe whether the post-RNA interference (RNAi) chondrocytes could be used as the seed cells of tissue engineered cartilage.

Chondrocytes were separated from Sprague Dawley rats. The first passage chondrocytes were used and divided into 2 groups: normal chondrocytes (control group) and post-RNAi (experimental group). Normal and post-RNAi chondrocytes were seeded into chitosan/gelatin material and cultured in vitro to prepare tissue engineered cartilage. The contents of Aggrecan and Aggrecanase-1, 2 were measured by HE and Masson staining, scanning electron microscope (SEM), and RT-PCR.

The histological results: no obvious difference was observed in cell number and extracellular matrix (ECM) between 2 groups at 2 weeks; when compared with control group, the secretion of ECM and the cell number increased in experimental group with time. The RT-PCR results: the expression of Aggrecan mRNA in experimental group was significantly higher than that in control group (P < 0.05); but the expressions of Aggrecanase-1, 2 mRNA in experimental group were significantly lower than those in control group (P < 0.05). The SEM results: the cell number in experimental group was obviously more than that in control group, and the cells in experimental group were conjugated closely.

The post-RNAi chondrocytes can be used as the seed cells for tissue engineered cartilage, which can secrete more Aggrecan than normal chondrocytes. But their biological activities need studying further.