Gold Nanorods Function as Near-Infrared Light-Activated Microheaters for In Situ Curing of Injectable Hydrogel Therapies

Injectable hydrogels have gained popularity as an attractivesolutionfor wound dressing therapies due to their ability to conform to irregularwound sites and in situ polymerization. However,the harmful effects of ultraviolet (UV) exposure limit the applicabilityof photocuring methods, while thermal curing is limited by its high-temperaturerequirement and nonselective curing. To address these limitations,we present a method of curing hydrogels in situ byincorporating gold nanorods (AuNRs) as microheaters to initiate andregulate local thermal polymerization of the hydrogel upon exposureto near-infrared (NIR) light. In the present method, the well-dispersedAuNRs in the hydrogel presolution enable millions of microheatersto heat up the solution, resulting in a faster kinetic rate and higherpolymerization conversion compared to the traditional thermal curingmethod. Moreover, the NIR light-initiated curing process leads toa more uniform microstructure and improved mechanical performanceof hydrogels. This in situ, fast, and selective curingmethod presents a superior alternative to traditional curing methodsand is an ideal choice for wound dressing therapies and other biomedicalapplications.