Fig. 3

Scaffold mechanical integrity measured using ultrasound. Representative ultrasound images of an alginate scaffold imbedded in agar. a A raw ultrasound image illustrating an alginate scaffold embedded in agar. b A shear modulus map from a portion of the raw ultrasound image. c A shear modulus map of alginate scaffold after removing signal contributed by the agar embedding medium. These shear measurements were used to calculate the average median Young’s modulus. Measurements and calculations were made as described in the “Methods”