PMID-35930707 – LL-37 Engineered Exosomes for Wound Healing
Su Y, et al. Engineered exosomes carrying LL-37 for wound healing. Adv Healthc Mater. 2022;11(21):e2200849.
Quick Reference
| Property | Value |
|---|---|
| PMID | 35930707 |
| DOI | 10.1002/adhm.202200849 |
| Year | 2022 |
| Journal | Advanced Healthcare Materials |
| Study Type | In vitro + Animal in vivo |
| Evidence Level | V |
| Sample | Cell cultures (fibroblasts, endothelial cells) and murine wound model |
| Peptide(s) Studied | LL-37 |
Key Findings
- LL-37-loaded engineered exosomes significantly enhanced wound healing in a murine full-thickness wound model compared to free LL-37 and control exosomes
- The exosome delivery system promoted angiogenesis, demonstrated by increased VEGF expression and new blood vessel formation at wound sites
- LL-37-exosomes enhanced fibroblast migration and proliferation in vitro, key processes for wound bed formation
- Collagen deposition was markedly increased in treated wounds, indicating improved extracellular matrix remodeling
- The formulation suppressed pro-inflammatory cytokines (TNF-α, IL-6) at the wound site, facilitating the transition from inflammatory to proliferative healing phases
- Exosome encapsulation protected LL-37 from enzymatic degradation and provided sustained release
Study Design
Combined in vitro and in vivo study. In vitro: human fibroblasts and endothelial cells were treated with LL-37-loaded exosomes to assess migration, proliferation, and tube formation. In vivo: full-thickness excisional wounds in mice were treated with LL-37-exosomes, free LL-37, blank exosomes, or vehicle. Wound closure, histology, immunohistochemistry for vascularization, collagen content, and inflammatory markers were assessed over 14 days.
Limitations
- Murine wound model; human wound healing differs in inflammatory response duration and scar formation
- Exosome engineering adds complexity that may limit clinical translatability of the specific delivery platform
- Free LL-37 comparison may not reflect optimal dosing of unencapsulated peptide
- No assessment of antimicrobial activity in the wound context, despite LL-37's known antimicrobial properties
Clinical Relevance
This study demonstrates that LL-37 promotes wound healing through multiple complementary mechanisms: angiogenesis, fibroblast activation, collagen deposition, and anti-inflammatory modulation. While the exosome delivery system is investigational, the findings confirm LL-37's intrinsic wound-healing properties beyond its established antimicrobial role. This supports clinical interest in LL-37 for wound management and tissue repair applications.
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#research #animal-in-vivo #evidence-level-V