Polymers featuring photoresponsive groups have been exploited as promising drug delivery systems with high degree of control over drug delivery processes. Light as spatially and temporally controllable external stimulus can be readily tuned and focused to trigger changes in the structure of polymer chains to provide “on-command” drug delivery. Generally, these photoresponsive polymeric materials respond to light with high energy wavelength, specifically ultraviolet (UV). 

We are investigating the use of NIR-to-UV/visible upconversion nanoparticles (UCNPs) as potential remote-controlled nanotransducers to generate in situ UV/visible light in order to activate the photoreaction of photoresponsive molecules for drug delivery applications. 

Using UCNPs as NIR-initiated controlled drug delivery systems offers unique advantages over conventional light-controlled systems with better tissue penetration depth and a reduced risk of cellular photo-damage caused by exposure to light at high-energy wavelengths.