Raman Microscopy and Imaging: Applications to Skin Pharmacology and Wound Healing - Emerging Raman Applications and Techniques in Biomedical and Pharmaceutical Fields - page 374

Fig. 15.10. Schematic and IR validation of the wound healing experiment a
Schematic of the wound healing experiment. Both wounded and non-wounded areas
were examined in each Raman and IR measurement. b Visible image of a typical
wound 4 days following wounding. The migrating epithelial tongue (MET) indicates
the persistence of healing in the explants. c Factor loadings of the IR data in the
amide I and II spectral regions. The loadings in the 1475-1750 cm − 1 region clearly
identify collagen (factor 1, solid line ) and keratin (factor 2, dashed line ). d Factor
score image of the collagen-rich factor 1. A brighter shade indicates the greater con-
tribution of the factor loading (and therefore collagen) to the pixel. e Factor score
image of the keratin-rich factor 2. A brighter shade indicates the greater contribution
of the factor loading (and therefore keratin) to the pixel

collected starting at m from the left edge of a wound into the non-

wounded area and scanning 170

∼ 60-80 μ

μ m into the wounded area with a depth of

∼ 60 μ m. This resulted in a measurement area ∼ 250 μ m wide and 60 μ m deep.

Spectra were acquired 12 h post-wounding. The spatial distribution of com-

ponents in this region is initially investigated using factor analysis conducted
over the 1140-1690 cm − 1 region. Factor loadings specific to the wounded area
12 h post-wounding are shown in Fig. 15.11a, and corresponding score images
are presented in Fig. 15.11b. In the loading plots (Fig. 15.11a), the amide
I and III contours of factors 1 and 2 are characteristic of collagen and ker-
atin, respectively. The score images reveal that collagen in the wounded area
is pressed up from the dermis, while the keratin in non-wounded area arises

∼