Abstract
Abstract
Impaired skin repair is associated with insufficient fibroblast activity and dysregulated extracellular matrix turnover. Extracellular vesicle-enriched preparations derived from multipotent mesenchymal stromal cells (MMSCs) may provide a cell-free approach to modulate these processes; however, the effects of preparations from genetically modified producer cells remain incompletely characterized. We evaluated preparations obtained from native MMSCs and from MMSCs separately transfected with OCT4/SOX2, HIF-1alpha, or Klotho expression plasmids. A 1:1:1 mixture of preparations from the three modified cell populations was examined as a combined treatment. Rat skin fibroblasts were exposed to the preparations for 24, 48, or 72 h. Fibroblast density and concentrations of matrix metalloproteinase-1 (MMP-1), matrix metalloproteinase-3 (MMP-3), collagen type I, and collagen type III were assessed. The combined preparation produced the largest observed increase in fibroblast density, reaching 112.63 +/−5.55 × 10^3 cells/cm2 at 72 h, compared with 40.60 +/−1.12 × 10^3 cells/cm2 for the native-MMSC preparation and 37.10 +/−3.01 × 10^3 cells/cm2 in the untreated control. At 24 h, MMP-1 and MMP-3 concentrations in the combined group were 140.0 +/−4.77 ng/mL and 144.0 +/−4.74 ng/mL, respectively, compared with 283.1 +/−25.2 ng/mL and 208.1 +/−39.2 ng/mL in controls. Collagen type III concentration increased to 1.95 +/−0.25 ng/mL at 72 h versus 1.15 +/−0.15 ng/mL in controls. These findings indicate that the combined preparation was associated with enhanced fibroblast proliferation and altered extracellular matrix remodeling in vitro. Interpretation is limited by triplicate technical replication, volume-based dosing, and incomplete vesicle characterization.