NIR- and UV-dual responsive amphiphilic copolymer micelles with light-dissociable PAG-side groups

Amphiphilic random copolymer micelle of P(NVP-co-NHPM) that responds to both UV and NIR light was designed and investigated. N-hydroxyphthalimide methacrylate—bearing a photoacid generator functional group was synthesized and used to construct the hydrophobic segment of P(NVP-co-NHPM); the N–O bond can be photocleaved when exposing the polymer aqueous solution to 310 nm UV light irradiation, inducing the micellar dissociation and delivery of loaded substances. Dynamic light scattering (DLS), atomic force microscope (AFM), and transmission electron microscopy (TEM) were used to characterize the micellar dissociation and controlled release processes. Moreover, the upconverting nanoparticles (NaLuF₄:Gd/Yb/Tm) that can effectively absorb NIR light and convert it into visible and UV light were coloaded into polymer micelles to activate the micellar dissociation and the delivery of loaded cargoes via 980 nm NIR light.