L. De Cola and co-workers report a nanocomposite hydrogel able to induce in vitro chemotaxis of stem cells on page 4881. The cover image shows a nanocomposite hydrogel containing mesoporous silica nanoparticles integrated into the polymeric network. The controlled release of SDF-1α from the hydrogel induced the chemotaxis of stem cells, while the optimal mechanical properties enhanced stem cells proliferation. These attractive properties together with the low inflammatory response in vivo make this hydrogel a promising material for tissue engineering applications.