Fig. 5.

Biochemical examination and immunohistochemical analysis of catabolic factors and cell apoptosis in engineered constructs in vitro. Expression of catabolic factors and cell apoptosis in the constructs with or without 3D culture were examined. (a): Gene expression of MMP-13 and caspase-3. Data are expressed as mean ± standard deviation. Statistical significance was evaluated using Dunnett's test. **p < 0.01 vs. the direct group. (b): Immunostaining for PCNA and TUNEL. Scale bars = 50 μm. (c): Positive ratios of PCNA and TUNEL were counted under a microscope (positive cells out of total cells,×20 magnification, average of 5 fields). Data are expressed as mean ± standard deviation. Statistical significance was evaluated using Dunnett's test. **p < 0.01, *p < 0.05 vs. the direct group.