The Polymer Society of Korea

Abstract

This study shows a non-toxic injectable hydrogel platform that induces second gelation and enables spatiotemporal patterning using focused ultrasound (FUS) without surgical incision. Biocompatible polymer polyethylene glycol (PEG) based PEGDA was used to synthesize pH-dependent injectable nanogels, where peroxides generated during synthesis. Nanogel enables body temperature-triggered additional reactions, forming high-modulus bulk hydrogels that overcome the mechanical limitations of conventional injectable hydrogels. Furthermore, selective FUS-mediated peroxide decomposition accelerates gelation kinetics and allows patterning at desired locations and shapes. Precise control over nanogel modulus and FUS intensity enables tailoring for diverse tissue environments, demonstrating potential as patient-specific tissue substitutes and localized drug delivery platforms.