NIR responsive AuNR/pNIPAM/PEGDA inverse opal hydrogel microcarriers for controllable drug delivery

Particle-based delivery systems have emerged as a powerful platform in controlled drug release. In the present study, we developed a new inverse opal hydrogel microcarrier system composed of gold nanorods (AuNRs) for near-infrared light (NIR) activated drug delivery. AuNRs with a desired aspect ratio were prepared by a seed-mediated growth method. The inverse opal hydrogel microcarriers composited with AuNRs were synthesized by negatively replicating silica colloidal crystal beads (SCCBs). The NIR-thermo response of the microcarriers was due to the NIR photothermal heating effect of AuNRs and the thermo responsive volume transition of poly(N-isopropylacrylamide) (pNIPAM) hydrogel. It was found that the NIR-controlled reversible shrinking response of the microcarriers was ideal for the controllable drug release with real-time self-reporting color indication.