Design of a near‐infrared‐triggered photo/thermal dual‐responsive composite carrier with excellent biocompatibility for controllable drug release.

A near‐infrared (NIR)‐triggered photo/thermal dual‐responsive composite carrier (UCNPs‐NG‐PDA) was designed and fabricated by the incorporation of upconversion nanoparticles (UCNPs), coumarin‐based photo/thermal‐responsive nanogel (NG) with uniform particle size (193 nm) and polydopamine (PDA) particles. UCNPs‐NG‐PDA has good photothermal conversion capability because of the introduction of PDA. The light and heat dual‐responsiveness of coumarin‐based nanogels markedly enhances the drug release of UCNPs‐NG‐PDA. Under NIR irradiation for only 20 min, the final cumulative release reaches 79.4% and is much higher than that (58.8%) under UV irradiation. More remarkably, the UCNPs‐NG‐PDA exhibits an excellent biocompatibility and has fascinating application prospects in drug delivery fields. [ABSTRACT FROM AUTHOR]