Evaluation of Shear Properties of Hydrogel

Abstract

Composite constructs made from gelatin methylacrylamide (gelMA) and polycaprolactone (PCL) have been proven as promising materials to form tissue equivalents which can be used to alleviate the problems arising due to damage of articular cartilage. Despite exhibiting an increase of compressive stiffness (up to 54 - fold) by synergistic combination of the two materials, as compared to gelMA or PCL fiber scaffolds alone, determination of shear properties of the composite construct remains unprecedented. The current study was aimed to comprehend the shear properties of the tissue equivalents made from gelMA or PCL fiber scaffolds. Direct shear tests were performed on composite constructs made from gelMA and boxed architecture of PCL fiber scaffolds with different fiber spacings to generate a comparative basis for shear modulus followed by computational modeling and analysis of the constructs to obtain a better understanding of reinforcing effect of PCL fiber scaffolds in gelMA and validate the experimental results computationally. Results indicate that shear stiffness of the tissue equivalent is dominated by the membrane elements of the boxed architecture of PCL fiber scaffolds which are produced by melt electrowriting (MEW). An association of increase in shear stiffness with decrease in fiber spacing for a given architecture has been depicted.