Chondrogenesis of adipose tissue-derived stem cells induced by auricular chondrocytes from microtia in vivo / 中国组织工程研究

ABSTRACT

BACKGROUND:Due to quantity and quality deficiencies, chondrocytes from microtia are difficult to act as seed cells to construct an ear cartilage scaffold with the normal human auricle size. OBJECTIVE: To test the hypothesis that auricular chondrocytes from microtia can promote chondrogenic differentiation and chondrogenesis of human adipose tissue-derived stem cells (ADSCs) at non-chondrogensis sitein vivo, which is the preparatory work for preparation of human tissue-engineered auricle cartilage scaffold. METHODS: Human ADSCs at passage 3 and auricular chondrocytes at passage 2 were mixed at a ratio of 73 and 5.0×1010/L mixed cells were suspended in 0.2 mL of 30% Pluronic F-127, and then the mixture was injected subcutaneously into Balb/c nude mice as experimental group. Auricular chondrocytes or ADSCs at the concentration of 5.0×1010/L were mixed with 0.2 mL of Pluronic F-127 and injected respectively as positive and negative control groups. 1.5×1010/L auricular chondrocytes were mixed and injected as low-concentration chondrocyte control group. All specimens were collected at the 8th week post-injection. Newborn tissues in nude mice were taken out for morphological examination, wet weight measurement, determination of glycosaminoglycans, histological and immunohistochemical staining. RESULTS AND CONCLUSION:The wet weight of specimens in the experimental group was over 80% of that in the positive control group, and the wet weight of specimens in the low-concentration chondrocyte control group was less than 30% of that in the positive control group. The average wet weight and glycosaminoglycan content were significantly higher in the experimental and positive control group than in the negative control and low-concentration chondrocyte control groups (P < 0.05). In all the groups except for the negative control group, mature cartilage lacunas could be observed by histological staining and collagen type Ⅱ could be detected for expression by immunohistochemistry to different extents. In the low concentration chondrocyte control group, cartilage lacunas were incompact and inhomogeneous, and the extracellular matrix was slightly stained. In the negative control group, mature cartilage lacunae and collagen type Ⅱ could not be detective. To conclude, auricular chondrocytes from microtia can promote chondrogenic differentiation and chondrogenesis of ADSCs at the non-chondrogenesis sitein vivo.