Ligand Coupling and Decoupling Modulates Stem Cell Fate

In natural microenvironment, various proteins containing adhesive ligands in fibrous and non-fibrous structures dynamically couple and decouple to regulate stem cell fate. Herein, materials presenting movably couplable ligands are developed by grafting liganded gold nanoparticles (AuNPs) to a substrate followed by flexibly grafting liganded movable linear nanomaterials (MLNs) to the substrate via a long bendable linker, thereby creating a space between the MLNs and the AuNPs in the decoupled state. Magnetic control of the MLNs decreases this space via the bending of the linker to couple the MLNs to the AuNPs. Remote control of ligand coupling stimulates integrin recruitment to the coupled ligands, thereby non-toxically facilitating the focal adhesion, mechanosensing, and potential differentiation of stem cells, which is suppressed by ligand decoupling. Versatile tuning of size, aspect ratio, distributions, and ligands of the MLNs can help to decipher dynamic ligand-coupling-dependent stem cell fate to advance regenerative therapies.