Nano 3D printing-enabled micropost array gradients

Here we introduce a two-photon Direct Laser Writing (DLW) strategy to create arrays of dual-structured microposts that vary in height (and therefore, stiffness) from post-to-post for cell mechanobiological studies. Using the Nanoscribe Professional GT system, we tuned the mechanical stiffness of each arrayed micropost through changes in relative heights of dual-structured posts. ANSYS simulations revealed that the theoretical stiffness of microposts could be modulated in the range of 2 to 250 nN/μm over the length of an array. Experimental results obtained from seeding human umbilical vein endothelial cells (HUVECs) revealed cell-generated traction forces up to 37.1 +/-7.2 nN. We envision that the ability to measure the traction forces of cells seeded on the presented stiffness gradients will enable researchers to better understand, and subsequently, control cellular behaviors, thereby impacting fields including tissue engineering, biomaterials, and regenerative medicine.