Fig. 1.

Schematic illustration of intracellular TGase-catalyzed polymerization and in situ controllable construction of nanostructures. The peptide monomer was composed of an elastin-based repeat unit, one-pair or two-pairs polymerization active sites, and a functional molecule. The TGase-instructed polymerization was performed via formation of isopeptide bond between the side chains of glutamine and lysine. Peptide monomers diffused into cells, and then polymerized intracellularly to form topology-controlled 1D elastin-like polypeptide (ELP) random coil, 3D ELP nanoparticle, and 3D ELP gel. These structure-differentiated ELPs exhibited diverse biological functions