Studying Cell Mechanobiology in 3D: The Two-Photon Lithography Approach.

Two-photon lithography is a laser writing technique that can produce 3D microstructures with resolutions below the diffraction limit. This review focuses on its applications to study mechanical properties of cells, an emerging field known as mechanobiology. We review 3D structural designs and materials in the context of new experimental designs, including estimating forces exerted by single cells, studying selective adhesion on substrates, and creating 3D networks of cells. We then focus on emerging applications, including structures for assessing cancer cell invasiveness, whose migration properties depend on the cell mechanical response to the environment, and 3D architectures and materials to study stem cell differentiation, as 3D structure shape and patterning play a key role in defining cell fates.