Extracellular Vesicle Therapy for Scar Reduction: A Systematic Review and Meta-Analysis
Summary: Systematic review/meta-analysis of 15 RCTs (n=800 post-surgical wounds) assessed extracellular vesicles (EVs, MSC/iPSC-derived) for scar modulation. EVs significantly reduced scar thickness (SMD -0.65, 95% CI -0.92 to -0.38, p<0.001) and fibrosis markers (α-SMA/collagen I ↓ 30%, p=0.002). Mechanisms: ↓ TGF-β1/SMAD3, ↑ anti-fibrotic miRNAs (miR-21, let-7a), M2 macrophage shift. No AEs; greater effects in hypertrophic scars. Supports EVs as safe adjunct for post-surgical fibrosis, with implications for DFU grafts/burns (GRADE moderate evidence).
Key Highlights:
- Scar Thickness: SMD -0.65 (25% reduction); optimal at 6 months.
- Fibrosis: ↓ α-SMA/collagen I 30%; via TGF-β1/SMAD3 inhibition.
- Mechanisms: M2 polarization, ↑ miR-21/let-7a; dose 10^9 EVs/site.
- Safety: No AEs; I²=45% heterogeneity; MSC > iPSC sources.
- Method: PRISMA; RCTs only; subgroup analysis by wound type.
Keywords: EVs, scar reduction, fibrosis, TGF-β, post-surgical, Li Wang, Jun Zhang, Min Chen