Photoactivation of Noncovalently Assembled Peptide Ligands on Carbon Nanotubes Enables the Dynamic Regulation of Stem Cell Differentiation.

ABSTRACT

Stimuli-responsive hybrid materials that combine the dynamic nature self-assembled organic nanostructures, unique photophysical properties of inorganic materials, and molecular recognition capability of biopolymers can provide sophisticated nanoarchitectures with unprecedented functions. In this report, infrared (IR)-responsive self-assembled peptide-carbon nanotube (CNT) hybrids that enable the spatiotemporal control of bioactive ligand multivalency and subsequent human neural stem cell (hNSC) differentiation are reported. The switching between the ligand presented and hidden states was controlled via IR-induced photothermal heating of CNTs, followed by the shrinkage of the thermoresponsive dendrimers that exhibited lower critical solution temperature (LCST) behavior. The control of the ligand spacing via molecular coassembly and IR-triggered ligand presentation promoted the sequential events of integrin receptor clustering and the differentiation of hNSCs into electrophysiologically functional neurons. Therefore, the combination of our nanohybrid with biomaterial scaffolds may be able to further improve effectiveness, durability, and functionality of the nanohybrid systems for spatiotemporal control of stem cell differentiation. Moreover, these responsive hybrids with remote-controllable functions can be developed as therapeutics for the treatment of neuronal disorders and as materials for the smart control of cell function.