Measurements of Elastic Properties of Biological Hydrogels using Atomic Force Microscopy

Biological hydrogels are widely used as extracellular environment for encapsulating and growing cells. Mechanical properties of hydrogels can influence cell function, mechanotransduction and cellular behavior such as growth, migration, adhesion, differentiation and morphology. Microenvironmental modulus of hydrogels dictates cell behavior and growth. The main purpose of the current study was to determine elastic modulus of two well-known hydrogels (Agarose and Gelatin Methacryloyl) using Atomic Force Microscope (AFM). The elastic modulus was calculated from force-deflection curve obtained by indenting an indenter in the direction normal to the plane of the gel surface. The elastic moduli of the prescribed gels were found to be strongly influenced by the level of concentration in the gel. Elastic modulus of 1% agarose and 2% agarose was found comparable with 10% GelMA and 20% GelMA, respectively. Results obtained from indentation experiments and those published in the literature revealed that AFM can be successfully and confidently used to determine elastic response of hydrogels in the solid state.