Fig. 5. Schematic illustration of (A) a simple strategy to fabricate catechin-keratin conjugate based nanoparticles; (B) molecular interactions of nanosphere assembly; and (C) administration of colloidally stable and glutathione (GSH)/enzyme dual stimuli-responsive nanoparticles with enhanced cancer therapy effects. Reproduced from ref. 64 with permission from Royal Society of Chemistry, copyright 2018.