Figure 4.

TNFα expression.

Notes: (A) TNFα concentrations were determined by ELISA in tissue homogenates of knee joints. (B) Immunostaining of TNFα-positive chondrocytes (black arrows). (C) Total and positive-stained chondrocytes were counted and presented as percentages. Values are the means ± SEM of eight mice (groups 1–4) and five mice (group 5). Statistical significance was assessed by unpaired Student’s t-test, *P<0.05, **P<0.01, ***P<0.001. Group 1: normal control; group 2: CAIA control; group 3: CAIA mice treated with CH-DEAE₁₅/siRNA-TNFα nanoparticles; group 4: CAIA mice treated with folate-PEG-CH-DEAE₁₅/siRNA-TNFα nanoparticles; group 5: CAIA mice treated with siRNA-TNFα.

Abbreviations: CAIA, collagen antibody-induced arthritis; CH, chitosan; CTX-II, C-terminal telopeptide type II collagen; DEAE, diethylethylamine; ELISA, enzyme-linked immunosorbent assay; PEG, polyethylene glycol; SEM, standard error of the means; TNFα, tumor necrosis factor-alpha.