Multifaceted effects of milk-exosomes (Mi-Exo) as a modulator of scar-free wound healing.

Scar-free treatment is complex involving many cells in the human body but a very elaborate reaction. This process demands regulation of various growth factors on behalf of TGFβ3 around the damaged tissue, and it is also important to protect cells from inflammatory reactions and oxidative stress to avoid abnormalities. Here, we focused on bovine derived milk exosomes (Mi-Exo) and their scar-free healing potential. The physiological properties (size and shape), biological markers (TSG101 and Bta-miR2478) and stability on storage of Mi-Exo were analyzed. Mi-Exo exhibited significant NP (number of Mi-Exo particles)-dependent scavenging activity in ABTS assay. In addition, Mi-Exo suppressed the expression of pro-inflammatory mediators, IL-6 and TNFα, and pro-inflammatory chemokines, COX-2 and iNOS. This study showed that cell migration was significantly inhibited in a Mi-Exo NP-dependent manner. We also evaluated the expression of TGFβ1 and TGFβ3 on the basis of mRNA and protein levels. Furthermore, the role of functional behavior of Mi-Exo in TGFβ1 maturation was explored. This is the first study to demonstrate that Mi-Exo may target the TGFβ signaling pathway, which plays important roles in scar-free wound healing.