Fig. 6. One-photon visible light photo-release of dexamethasone from an implanted depot reduces carrageenan-induced hind paw inflammation in mice. (a) Composition of P-1-Dex particle depot. (b) Representative IVIS image of mice implanted with NIR fluorescent P-1-Dex depot before irradiation. (c) Photograph illustrating irradiation of the P-1-Dex depot with blue visible light (λ _ex = 400–500 nm, 0.18 W, 0.21 W cm^–2, 432 J h^–1). (d) Maximal inflamed hind paw thickness increase at t = 5 h after carrageenan injection. The P-1-Dex dose was 200 μg containing 2 μg Dex; free Dex dose was 2 μg; all mice were injected with a total of 25 μL of solution. n = 3 for all groups except DPBS, for which n = 6. Drug depots were injected in the left hind hock 1 h before inflammation was induced with carrageenan (2% w/v in 25 μL DPBS) in the left hind footpad. Hind paw thickness was measured using a caliper (see Fig. S9†) and the results are plotted relative to the non-inflamed right hind paw (injected at the same time with DPBS). Error bars are standard error of mean; *p = 0.02, n.s. = not statistically significant.