Fig. 2From: Silk fibroin hydrogel scaffolds incorporated with chitosan nanoparticles repair articular cartilage defects by regulating TGF-β1 and BMP-2Characterization of BMP-2@SF hydrogel. a SEM images of BMP-2@SF hydrogel (× 400). b Pore diameter of BMP-2@SF hydrogel. c In vitro release of BMP-2 measured by ELISA. The results were measurement data and expressed as mean ± standard deviation derived from at least 3 independent experiments. Data comparison among multiple groups was analyzed by one-way ANOVA, followed by Tukey’s post hoc testBack to article page