Co-culture of RhoA-overexpressed microtia chondrocytes and adipose-derived stem cells in the construction of tissue-engineered ear-shaped cartilage.

Microtia is a congenital auricle dysplasia with a high incidence and tissue engineering technology provides a promising strategy to reconstruct auricles. We previously described that the engineered cartilage constructed from microtia chondrocytes exhibited inferior levels of biochemical and biomechanical properties, which was proposed to be resulted of the decreased migration ability of microtia chondrocytes. In the current study, we found that Rho GTPase members were deficient in microtia chondrocytes. By overexpressing RhoA, Rac1, and CDC42, respectively, we further demonstrated that RhoA took great responsibility for the decreased migration ability of microtia chondrocytes. Moreover, we constructed PGA/PLA scaffold-based cartilages to verify the chondrogenic ability of RhoA overexpressed microtia chondrocytes, and the results showed that overexpressing RhoA was of limited help in improving the quality of microtia chondrocyte engineered cartilage. However, coculture of adipose-derived stem cells (ADSCs) significantly improved the biochemical and biomechanical properties of engineered cartilage. Especially, coculture of RhoA overexpressed microtia chondrocytes and ADSCs produced an excellent effect on the wet weight, cartilage-specific extracellular matrix, and biomechanical property of engineered cartilage. Furthermore, we presented that coculture of RhoA overexpressed microtia chondrocytes and ADSCs combined with human ear-shaped PGA/PLA scaffold and titanium alloy stent fabricated by CAD/CAM and 3D printing technology effectively constructed and maintained auricle structure in vivo. Collectively, our results provide evidence for the essential role of RhoA in microtia chondrocytes and a developed strategy for the construction of patient-specific tissue-engineered auricular cartilage.