Fig. 8

Immunohistochemical staining of collagen type II (a–f) as well as gene expression analysis (g) reflected the significantly higher collagen type II synthesis of hCh compared to mnCPC. On day 14, hCh demonstrated a slight collagen type II synthesis in the superficial cell layer on the construct surface (d) while mnCPC exhibited no collagen type II production. During the 3D culture for up to 42 days, collagen type II synthesis of hCh increased (d–f). This increase was additionally detected on gene expression level. mnCPC (a–c) demonstrated a slight collagen type II synthesis starting from day 28 (b, g) and increasing until day 42 (c, g). The scaffold matrix consists of collagen type II and reacted strongly with the collagen type II antibody (Fig. 6h). The values represent the mean ± SD with n = 8 donors for each cell type, *p ≤ 0.05