FIGURE 4.

GMSC‐Exo alleviates the inflammatory responses in collagen‐induced arthritis (CIA) mice. CIA was induced in DBA/1 mice and after booster immunization at Day 21, mice were treated with GMSC‐Exo (165 µg per mouse, i.v.), GMSC (1 × 10⁶ per mouse, i.v.) or PBS, and euthanized on Day 56. (A, B, C) The representative images of gross appearance of swollen hind paws. (D‐E) Arthritis severity scores and paw thickness were determined at various time points after immunization. Compared with PBS‐treated group, arthritis scores in GMSC‐ or GMSC‐Exo‐treated group: **p < 0.01, ^## p < 0.01. Data are mean ± SD, n = 6 mice. (F) Incidences of CIA mice. n = 6 mice. (G, H, I) Histological analysis of whole ankle joints was shown. In PBS‐treated mice, inflammatory cells fill the joint cavity, and bone and cartilage are severely destroyed. After GMSC‐Exo or GMSC treatment, the degree of inflammation and bone destruction has been greatly improved. CIA, collagen‐induced arthritis; GMSC, gingival mesenchymal stem cells; GMSC‐Exo, gingival mesenchymal stem cell‐derived exosomes; PBS, phosphate‐buffered saline