Fig. 6

Local delivery of TA-loaded TG-18 hydrogel demonstrates therapeutic efficacy in severe arthritis. a Experimental outline: Arthritis was induced by i.p. injection of 75 µl K/BxN serum on day 0 and day 2. Immediately after the second dose of K/BxN serum, animals were randomized into four groups. The right hindpaw of each mouse was injected with hydogel on day 2 and day 6. The (Blank gel→Blank gel) group received blank hydrogel (4 µl) twice, (TA gel→Blank gel) mice received TA-loaded TG-18 hydrogel (20 mg TA/ml, 4 µl) on day 2 and blank hydrogel on day 6, the (TA gel→TA gel) group received two doses of TA-loaded TG-18 hydrogel, and the (Blank gel→TA gel) group received blank hydrogel on day 2 and TA-loaded TG-18 hydrogel on day 6. Every other day, arthritis severity was scored clinically and paw swelling was measured with calipers. b, c RHP clinical score curves and their AUCs and d, e Change in RHP thickness curves and their AUCs for (Blank gel → Blank gel), (TA gel → Blank gel), and (TA gel → TA gel) (**P < 0.01, ***P < 0.001, ****P < 0.0001). f, g RHP clinical score curves and their AUCs and h, i Change in RHP paw thickness curves and their AUCs for (Blank gel → Blank gel) and (Blank gel → TA gel) (*P < 0.05, ****P < 0.0001). For c, e, P-values were determined by one-way Anova with Tukey’s post hoc analysis and for g, i, by Student’s t-test with Welch’s correction. Data are means ± SEM (n = 6 mice per group)