Viability of Articular Chondrocytes (AC) cultured in 3D scaffolds at different time points. PCL, PCL/RAD composite, and RAD scaffolds were seeded with AC and incubated with MTT to assess cell viability and distribution. (A) Construct appearance after MTT incubation at 4 days of culture with expansion medium. The same constructs were incubated in the absence of MTT reagent as a negative control; (B) Construct appearance after MTT incubation at 4 weeks of culture with the different culture media: expansion, control and chondrogenic media; (C) MTT values at 4 weeks of culture were expressed of formazan (product) absorbance at 550 nm. (Statistical differences are indicated as: * for p < 0.05, ** for p < 0.01, and *** for p < 0.001, Two-way ANOVA, N = 2 n = 3).