Fig.6
Pathological examination of wound tissue — Masson’s Trichrome
staining of Tissue
Type I and Type III proteins have their main distribution in the dermis,
while Type IV and Type VII are chiefly located within the subcutaneous
tissue [47-50]. Before delving into a specific
analysis of the collagen types and their distribution in samples at
various time points as represented in Fig. 7, an elementary examination
was conducted on the Sirius Red-stained microstructure under a 400x
magnification. Initially, on the third day subsequent to the initial
laser welding, sporadic deposition of COL-1 fibers around the wound was
observed, with the most considerable being in the 90° laser group. After
the application of the second laser welding, the groups subjected to
deflected laser incident angles presented a significantly greater COL-I
fiber deposition compared to the 90° laser group. This observation
suggests that following two instances of laser welding, the wound area
in the 90° laser group had become more supple and softer. COL-1 fibers,
which are densely aligned and relatively rigid, offer structural
support, whereas COL-3 fibers contribute to the flexibility of the
tissue, primarily affecting the skin’s softness. In normal tissues, the
Type I to Type III collagen ratio typically fluctuates between 1:1 and
2:1. Any significant deviation from this range may suggest instability
in the skin’s collagen structure [51-52].