Preparation of Pluronic F127 gels. Pluronic F127 was added to cold PBS (4 °C) to reach a concentration of 18 wt. %. This solution was stored in the fridge (4 °C) to keep the solution in a liquidlike stage: at 37 °C the Pluronic F127 solution turns into a gel. Particle tracking analysis. Pluronic F127 and TiTannic gels were prepared as described above to a final volume of 480 µL, which included 10 µL of 10% polystyrene microparticle dispersion which was dispersed in the gel precursor prior to gelation for homogenous distribution throughout the final gel. After gelation for 1 hour at 37 °C, microscopy videos of the particles inside the gels were acquired in bright-field mode using an Olympus BX51 microscope at 10 frames per second for 60 seconds.