Articular cartilage has restricted self-regenerative capacity; therefore, treatment of cartilage lesions is a great challenge in the field of orthopedics. In the present study, we evaluate the enhancing effect of a transforming growth factor-beta 1 (TGF-β1)-immobilized scaffold, fabricated by incorporating TGF-β1-loaded gelatin microspheres into PLGA framework, on the differentiation of adipose-derived stem cells (ASCs) into chondrocytes. Significant increase in cell proliferation was observed in the TGF-β1-immobilized PLGA-gelatin scaffold, as compared with the ASC-seeded non-TGF-β1-immobilized PLGA-gelatin scaffold. When chondrogenic differentiation of ASCs was evaluated for both constructs, sulfated glycosaminoglycan (sGAG) content was significantly higher in the TGF-β1-immobilized scaffold. This study showed that ASCs containing the TGF-β1-immobilized scaffold better promoted cartilage regeneration in defective articular cartilage, which is assessed by histological observation. Based on the above results, we conclude that TGF-β1-immobilized PLGA-gelatin scaffold seeded with ASCs considerably enhances the quality of the tissue-engineered cartilage, therefore, advancing the field of cartilage tissue engineering.

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It has been examined to disperse the Au nano-particles directly into liquid by replacing the solid substrate with low-vapor oil in a plasma sputtering apparatus. The dispersing particles in oil are much smaller than the conventional methods. Under low density of particles on oil, the intense absorbance peak is detected around 325nm and the shape and peak of absorption spectra don’t almost change following time, and the size of Au particles is steady. With higher density, the absorbance peak is stronger and shifts to visible light about 20nm. With prolonging measuring time, absorption peaks fall and a new absorption locating on around 550nm gradually appears, large numbers of particles gradually convert and produce the new particles sizes around 3-5nm. under high density, the other intense absorbance peak exists around 540nm besides the peak of 350 nm. High particles density produces the particles sizes around 5-7nm, and the contents and sizes of particles are basic invariablenes against measured period.