Photodynamic therapy accelerates skin wound healing through promoting re-epithelialization

Area of Science:

• Dermatology
• Regenerative Medicine
• Photobiology

Background:

• Epidermal stem cells (EpSCs) are crucial for skin homeostasis and wound repair.
• The impact of photochemical activation on EpSC behavior during healing remains unclear.

Purpose of the Study:

• To investigate the effects of photodynamic therapy (PDT) on wound healing processes.
• To determine PDT's influence on epidermal stem cell (EpSC) differentiation, proliferation, and migration.

Main Methods:

• Established mouse full-thickness skin resection models for in vivo studies.
• Administered 5-aminolevulinic acid (ALA) for PDT and analyzed wound healing via gross evaluation and H&E staining.
• Assessed EpSC protein expression, migration, apoptosis, and differentiation in vitro using flow cytometry and immunohistochemistry.

Main Results:

• PDT significantly accelerated wound closure by enhancing EpSC differentiation, proliferation, and migration.
• PDT promoted re-epithelialization and angiogenesis while reducing inflammatory markers.
• Increased proportion of transient amplifying cells and enhanced EpSC migration were observed post-PDT.

Conclusions:

• Topical ALA-induced PDT effectively stimulates wound healing.
• PDT enhances re-epithelialization, angiogenesis, and modulates skin homeostasis.
• This study provides a foundation for clinical applications of ALA-induced PDT in skin wound treatment.