In situ self-assembly of gold nanorods with thermal-responsive microgel for multi-synergistic remote drug delivery

Multi-responsive hybrid microgels have attracted lots of attention in biomedical filed owing to the tunable degree of flexibility, high particle stability, and remarkable sensitivity to external stimuli. In this paper, a novel remote drug delivery platform based on gold nanorods (AuNRs)-P(NIPAM-co-AAc) (PNA) hybrid microgel was prepared by electrostatic self-assembly approach. The electrostatic self-assembly of mercapto-modified polyethylene glycol (mPEG) and polyallylamine hydrochloride (PAH) was utilized to safeguard AuNRs, which could greatly enhance the stability of AuNRs and endow AuNRs-PNA hybrid microgels with excellent physiological dispersibility and stability. More importantly, due to the change of electrostatic force between microgels and DOX at different pH values, as well as the thermal sensitivity of PNA and NIR response of AuNRs, AuNR-PNA hybrid microgels displayed prominently pH/temperature/NIR synergistic responsive drug release performance. This paper furnishes a green and feasible method to prepare intelligently remotely controllable hybrid microgels with great physiological stability, which has great perspectives in photothermal therapy and remotely controllable drug delivery area. Graphical abstract pH/temperature/NIR synergistic responsive AuNRs-P(NIPAM-co-AAc) hybrid microgel for smart drug delivery was prepared by in situ self-assembly.