獲刊登於Lasers in Surgery and Medicine期刊。
Enhancing hair follicle regeneration by nonablative fractional laser: Assessment of irradiation parameters and tissue response.
作者：吳岳峰, 王修含, 吳佩珊, 范邁儀, 邱顯鎰, 蔡宗樺, 林頌然
Background and Objective
Study Design/Materials and Methods
Fig. 1. Laser irradiation. A. The skin on sides of the trunk was firmly stretched and irradiated with
a 1,550nm fractional erbium-glass laser. B. The red rectangle indicated the irradiated area. C.
Schematic diagram of the post-natal synchronized hair cycles on the back of C57BL/6 mice. The
second telogen started at week 7 and persisted for about 5 weeks. Laser irradiation was performed
on week 8. M: morphogenesis; C: catagen; T: telogen; A: anagen.
|Fig. 2. Laser beam energy and MTZ. Irradiated skin was sampled 1 day after irradiation. A.
Histology. MTZ could be identified by denatured collagen that showed a homogenized bluish
change. H&E staining. Bar¼100 mm. B. There was an increasing trend of the depth of MTZ as
beam energy was elevated. *P<0.05 compared with 5mJ group (N¼5). C. There was an
increasing trend of the width of MTZ as beam energy was elevated. *P<0.05 compared with 5mJ
Fig. 3. The effect of laser irradiation parameters on anagen induction and ulcer formation. A. Laser
beam energy was increased from 5 to 35mJ and laser beam density was increased from 500 to
3500MTZ/cm2. Yellow color indicated the therapeutic window in which premature anagen was
induced without ulcer formation. B. Quantification of the dynamics of anagen entry at various
irradiation parameters. P<0.05 compared with day 0 (N=5) in each group. 80103mm.
Fig. 4. Changes of skin and hair cycles. Laser beam energy was 15 mJ. At beam density of 552 MTZ/
cm2, no premature anagen entry was induced. At beam density of 1048MTZ/cm2, irradiated skin
started to turn grayish on day 9 to day 11(blue arrow head), indicating initiation of anagen. No skin
erosion or ulcer was observed. At beam density of 1600MTZ/cm2 and 2010MTZ/cm2, an ulcer
developed in the center of irradiated skin on day 5 and day 7 respectively (red arrow head).
Premature anagen entry surrounding the scar tissue was observed (yellow arrow head).
Fig. 5. Histological changes during hair cycle progression. Beam energy was 15mJ and beam
density was 1048MTZ/cm2. A. Comparison of gross skin change and histology. H&E staining.
Bar?100mm. B. Quantification of anagen entry area. * P<0.05 compared with day 0 (N=5). C.
Quantification of hair follicle length. * P<0.05 compared with day 0 (N=5).
Fig. 6(A). Dynamic changes of cell proliferation in hair follicles. Beam energy was 15mJ and beam
density was 1048MTZ/cm2. A. Double staining for BrdU and p-cadherin.
Fig. 6(B). Dynamic changes of cell proliferation in hair follicles. Beam energy was 15mJ and beam
density was 1048MTZ/cm2. A. Double staining for BrdU and p-cadherin. B. Double staining for
BrdU and K15. Secondary hair germ was positive for p-cadherin and HFSC was identified by K15.
From day 1 to day 5, BrdU was positive above bulge (yellow arrow heads). On day 7, BrdU was
positive in secondary hair germ to lower bulge (white arrow heads). On day 9 and day 11, BrdU was positive in bulge (red arrow heads). Many BrdU positive cells could be found in the hair matrix on day 9 to day 13 (green arrow heads). DP: dermal papilla; SG: secondary hair germ; BG: bulge.
Fig. 7. Expression of IL-6 (A), TNF-a (B), and IL-1b (C) after laser
irradiation of varied beam densities. Laser beam energy was
15 mJ. At beam density of 552 MTZ/cm2, very slight increase of IL-
6, TNF-a, and IL-1b was detected after irradiation. At beam
density of 1048MTZ/cm2, a moderate increase of IL-6, TNF-a, and
IL-1b was observed from day 1 to day 3. At beam density of
1600MTZ/cm2, prolonged and higher levels of IL-6, TNF-a, and
IL-1b were observed.
- 1,550-nm erbium glass laser;
- hair follicle regeneration;
- stem cell;
Lasers Surg. Med. 47:331–341, 2015. © 2015 Wiley Periodicals, Inc.