Figure 5: Efficacy in a rat model of arthritis. The rats were inoculated intradermally, into the plantar surface of the right hindpaw, with 0.1 ml of complete Freund’s adjuvant (CFA) containing 10 mg ml−1 of heat-killed Mycobacterium tuberculosis suspended in paraffin oil. The rats were allocated to 5 groups. A control group (naked DNA, ), a natural Ch-IL-1Ra plasmid DNA nanoparticles group ( ) and a Ch-Fa-IL-1Ra plasmid DNA nanoparticles group ( ) were injected on day 18 post AIA induction. A nontreated group (Rheumatoid arthritis, RA) ( ) was used as an untreated control. All animals were sacrificed on day 35 and clinical results were compared among the groups. (a) Rat’s ankle size change before and after treatments. Graph shows changes of absolute ankle size (mm) in AIA rats before and after different treatments at day 18. Each point represents the mean ± SD. Note a significant decreasing inflammation with Ch-Fa-Il-1Ra gene therapy ( , ) comparing to the AIA nontreated control. Differences observed between all treated groups were nonsignificant (NS). (b) IL-1β concentration in rat sera. All treated groups showed significant decrease IL-1Ra in serum ( , ) compared to nontreated controls. It can be clearly seen that this effect is observed the day after treatment starts. Black arrow indicates the day of starting IL-1Ra gene therapy. (c) PGE2 level in rat sera after Il-1Ra treatment. All values are expressed as means ± SD and were subjected to t test and one-way ANOVA analysis. A value of 0.05 was considered significant. There is a significant decrease in the levels of PGE2 in all three treatment groups (* , ** ).