Fig. 10

Engineered-Exo promoted the survival, proliferation and new cartilage formation of 3D-cultured tissue-engineered cartilage. (A) Cellular uptake assay by confocal microscopy imaging demonstrated rapid uptake of Engineered-Exo (red) at the different time points. (B) Representative images showing the live and dead microtia chondrocytes seeded on Gelma hydrogel, and (C) the comparison for the rate of live cell between Engineered-Exo and PBS control. Scale bar: 500 μm. Green: live microtia chondrocytes. Red: dead microtia chondrocytes. (D) Cell proliferation assessed by the Cell Counting Kit-8 at the specific time points after the exposure to Engineered-Exo or PBS. (E) Quantitative RT-PCR analysis showed regulation of genes associated with anti-apoptosis (PTEN, Survivin, Bcl-2), proliferation (PTEN, PCNA, FGF-2), as well as chondrogenic differentiation and ear cartilage matrix proteins synthesis (PTEN, TGF-β1, COL2A1, ACAN, ELN, SOX9 and COMP). The genes (COL1A1 and MMP 9) unfavorable for the synthesis of hyaline cartilage and elastic cartilage were also assessed. In particular, the tendency of expression of several chondrogenesis-related genes (COL2A1, ACAN, ELN, SOX9 and COL1A1) was described. (F) The protein levels of elastin, collagen II, and SOX9 in microtia chondrocytes were analyzed by western blotting. Data was presented as the mean ±SD of three number of replicates. ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001, ∗∗∗∗p < 0.0001