FLIM Reveals Red Light-Induced Changes in Murine Hair Follicles
Shanjie Xu1, Aoshan Wang1, Yuxuan Lin1
1State Key Laboratory of Radio Frequency Heterogeneous Integration (Shenzhen University), Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China.
Biosensors
|May 26, 2026
Summary
Low-level laser therapy (LLLT) using red light significantly boosts hair regeneration by increasing hair follicles and ATP levels. Fluorescence lifetime imaging microscopy (FLIM) offers a sensitive method to evaluate LLLT
Area of Science:
- Dermatology
- Biophotonics
- Regenerative Medicine
Background:
- Hair loss conditions like androgenetic alopecia (AGA) and alopecia areata (AA) have significant psychosocial effects.
- Low-level laser therapy (LLLT) presents a non-invasive, safe alternative to traditional hair loss treatments.
- Understanding LLLT's mechanism on hair follicles and skin requires advanced imaging techniques.
Purpose of the Study:
- To investigate the effects of 650 nm red-light irradiation on hair follicle dynamics and the cutaneous microenvironment.
- To evaluate the efficacy of LLLT in a mouse model of hair regeneration.
- To explore the utility of fluorescence lifetime imaging microscopy (FLIM) in assessing LLLT-induced changes.
Main Methods:
- Established a hair regeneration model in C57BL/6 mice.
- Applied 650 nm red-light irradiation (± 20 nm bandwidth).
- Utilized hematoxylin and eosin (H&E) staining and FLIM for morphological and metabolic assessment, including phasor plot analysis.
Main Results:
- Red-light irradiation significantly increased hair follicle count.
- Adenosine triphosphate (ATP) levels in the skin tissue were elevated post-irradiation.
- FLIM revealed prolonged fluorescence lifetimes in irradiated skin, indicating metabolic microenvironment alterations.
- Phasor plot analysis demonstrated FLIM's accuracy in differentiating hair follicles and surrounding structures.
Conclusions:
- LLLT effectively promotes hair regeneration.
- FLIM provides valuable, quantitative insights into LLLT's effects on the skin's metabolic state.
- FLIM is a promising tool for evaluating phototherapeutic efficacy in translational hair growth research.
