Near-Infrared Light-Controlled Activation of Adhesive Peptides Regulates Cell Adhesion and Multidifferentiation in Mesenchymal Stem Cells on an Up-Conversion Substrate.

Cell adhesion and differentiation can be regulated through material engineering, but current methods have low temporal and spatial accuracy to control invivo. Here, we developed an up-conversion nanoparticle (UCNP) substrate to regulate cell adhesion and multidifferentiation in mesenchymal stem cells (MSCs) by near-infrared (NIR) light. First, the cell-adhesive peptide Arg-Gly-Asp (RGD) was conjugated on the surface of UCNPs, and the photocleavage 4-(hydroxymethyl)-3-nitrobenzoic acid (ONA) was connected to RGD. Then, the photoactivated UCNPs were linked to cover glass to form UCNP-substrate. Under the NIR, the up-convert UV from UCNPs triggered the release of ONA and exposed RGD to change the cell-matrix interactions dynamically for cell adhesion and spreading. Moreover, MSCs cultured on UCNP-substrate could be specifically induced to multidifferentiate adipocytes or osteoblasts via different power and periods of NIR irradiation in vitro and in vivo. Our work demonstrates a new way to control cell adhesion and multidifferentiation by light for regeneration medicine.