Inhibitory effects and mechanisms of low-temperature plasma on hypertrophic scar

Recent advancements in comprehending the properties of low-temperature plasmas (LTPs) have spurred the creation of plasma medicine. Nonetheless, there exists limited scientific evidence concerning its mechanism of impeding proliferative scarring. This study aims to investigate the role of LTPs in hypertrophic scar (HS) formation. Establishing rabbit ear scar models, two groups were individually treated with salvianolic acid B (SAB) gel and low-temperature plasmas for six weeks, while the control group was not treated. The expression levels of cytokines, including TGF-β1, p-Smad3, and MMP-2, in rabbit serum were assessed using ELISA in this study. Additionally, hematoxylin-eosin staining and Masson’s trichrome staining were conducted on proliferative scar tissue to observe the arrangement of collagen fibers and determine the density of fibroblasts. Immunohistochemical analysis was also performed to obtain the percentage of type I collagen and α-SMA positive expression area. The findings indicated that the scars in both the SAB and LTP groups were narrower than those in the model group. The scar tissues treated with LTP or SAB showed a lower level of TGF-β1 and p-Smad3. In addition, α-SMA was significantly reduced in the LTP-treated group. Furthermore, the type I collagen expression was lower in the LTP group. These results suggest that LTP could have a comparable effect to SAB in hindering the development of HSs. It could potentially enhance skin scarring by impeding collagen deposition and fibroblast proliferation in HSs via the TGF-β/Smad signaling pathway. This investigation may provide a new perspective on HS treatment.