Next, to investigate the chemical-mechanical responsivity of the round porous DNA microcapsules, PEG (final concentration of ~1.25%) was added to a surrounding buffer solution of the round porous DNA microcapsules. Figure shows the time-lapse images of the 3D-reconstructed CLSM images of the shrinkage of the round porous DNA microcapsules after the addition of PEG. Interestingly, during shrinkage, the shapes of the round porous DNA microcapsules were similar. In contrast, although the same experiments were done for regular DNA hydrogel microparticles, they hardly shrank even after adding the PEG solution (Figure ). The size of the round porous DNA microcapsules 15 min after the addition of PEG decreased to ~34% in diameter (~4% in volume) (Figure ), and the size of the microparticles decreased to ~94% in diameter (~83% in volume). This shrinkage was probably induced by the osmotic pressure exerted inside and outside the DNA hydrogels. After the removal of PEG from the solution, the round porous DNA microcapsules did not recover. These results suggest that the round porous DNA microcapsule was soft and that the mesh structures of the DNA hydrogel may have been rearranged. This result demonstrated that the round porous DNA microcapsules had chemical-mechanical responsivity and their size could be tuned depending on the chemical environment.