Near-infrared light triggered release of molecules from supramolecular hydrogel-nanorod composites

Aim: To develop a stimulus-responsive material platform capable of releasing entrapped molecules in response to near infrared (NIR) light. Materials & methods: Gold nanorods were mixed with hyaluronic acid derivatives modified with beta-cyclodextrin or adamantane to create a NIR-responsive hydrogel-nanorod composite. Microfluidics were used to create responsive microgels and NIR-triggered release was evaluated. Results & discussion: The hydrogel-nanorod composite material exhibited a rapid response to NIR-irradiation, allowing enhanced release of encapsulated payloads with material heating and network disruption. The release was dependent on the entrapped molecule size, the NIR exposure time and the light intensity. Conclusion: NIR irradiation of hydrogel-nanorods leads to plasmonic heating and triggered release of encapsulated molecules, a system that has potential for light-triggered release of therapeutics.