UV- and NIR-responsive polymeric nanomedicines for on-demand drug delivery

Ultraviolet (UV) and near infrared (NIR) light-responsive polymeric nanomedicines (e.g., cargo-loaded micelles and vesicles) have increasingly received much attention for their applications in the spatiotemporal and on-demand drug delivery and disease therapy. This UV/NIR-sensitivity is activated via a one-photon and/or two-photon absorption process. The phototriggered micellar disruption and drug release have three mechanisms: (1) the hydrophobicity-hydrophilicity transition, (2) the photocleavage reaction, and (3) the cascade depolymerization reaction (e.g., self-immolative polymers). As NIR light can penetrate deeply into tissues (up to several inches) with less damage and scattering compared with UV and visible light, the polymeric nanomedicines simultaneously exhibiting both UV- and NIR-sensitivity hold great potential in clinical medicine and are especially discussed in this review.