Fabrication of multi-responsive dynamic poly(ethylene glycol)-iron oxide nanoparticle nanocomposite hydrogels through interfacial boronate-catechol crosslinking

Poly(ethylene glycol) (PEG)-based nanocomposite (NC) hydrogel with multiple advantageous properties such as high mechanical strength and stimuli-responsiveness have been demonstrated as promising materials across various fields. Here, an innovative type of PEG-based NC hydrogels is fabricated using phenylboronic acid-polyethyleneimine (PBA-PEI)-functionalized iron oxide nanoparticles (PP-IOPs) to crosslink the dopamine-modified 4arm-PEG (DA-4APEG) through boronate-catechol crosslinking. DA-4APEG/PP-IOP NC hydrogels exhibit tunable microstructures (i.e., pore size) and properties (i.e., rheological, mechanical, and swelling behaviors) by changing the number of PP-IOPs in the hydrogel network. With the dynamic crosslinks and magnetic nanoparticles in the network, DA-4APEG/PP-IOP NC hydrogels are self-healable and also responsive to various stimuli, including temperature, pH, glucose, dopamine, hydrogen peroxide, magnetic field, and near-infrared light. Therefore, a versatile PEG-based hydrogel platform has been developed, featuring customizable properties, multiple stimuli-responsiveness, and dynamic characteristics, making it suitable for advanced applications.