A151 ODN loaded exosomes produced under 3D conditions (A151-loaded Exo3D) reduced inflammatory capacity of macrophages and T-lymphocyte cell numbers at late stages of wound healing. Differences in spleen macrophage and T-cell populations at day 14 of mice treated with Exo3D, Exo2D, A151-loaded Exo3D, A151-loaded Exo2D, A151 ODN or PBS (CTRL) analysed by flow cytometry. Data is shown as mean ± SEM. n = 5–7. * p < 0.05, ** p < 0.01, *** p < 0.001. Abbreviations: Exo3D - exosomes derived from UC-MSC cultured in 3D conditions; Exo2D - exosomes derived from UC-MSC cultured in 2D conditions; A151 ODN – immunosuppressor A151 oligodeoxynucleotide; A151-loaded Exo3D - exosomes produced under 3D culture conditions loaded with A151 ODN; A151-loaded Exo2D - exosomes produced under 2D culture conditions loaded with A151 ODN.