The transition temperature of poly(N-acryloyl glycinamide) (PNAGA), a well-known UCST polymer can be adjusted by copolymerizing NAGA with AAm. This strategy can lead to values close to physiological temperature, making it possible to achieve controlled delivery of drugs. For instance, this has been applied to trigger the release of doxorubicin (Dox) from a poly(N-acryloyl glycinamide-co-acrylamide) (PNAAm) hydrogel containing polyDAcoated gold NPs (PDA-Au NPs) by exploiting the weakening of physical crosslinking and the gel-sol transition of the hydrogel, induced by the increase in temperature upon exposure to near-infrared (NIR) light. (Figure ). Similarly, the increase in temperature upon irradiation triggered contraction of a hydrogel made of poly(ethylene imine) (PEI) covalently linked to four-armed star-shaped poly(2-(dimethylamino) ethyl methacrylate-co-2hydroxyethyl methacrylate) modified with tert-butyl acetoacetate (SP(DMAEMA-co-HEMA-AA). This was due to the UCST behavior of the DMAEMA blocks, which was used for the efficient release of Dox (Figure ). Phototriggered temperature increase and Dox release from PNAAm-PDA-Au hydrogel with and without NIR light irradiation. Adapted with permission. Copyright 2018 Wiley-VCH. and 1.0 W cm -2 ) or without NIR irradiation. Adapted with permission. Copyright 2020 American Chemical Society.