Fig.8 Representative images of wound tissue sections stained by FITC in different treatment groups on different days (Scale bar ¼ 100 μm). (B) Quantification of the Fluorescence intensity of FITC staining in different treatment groups on different days. (n ¼ 3). Data represent mean \(\pm\)SD; *, P < 0.05, **, P < 0.01, ***, P < 0.001.
Throughout the healing process, Transforming Growth Factor-β (TGF-β) serves as a key regulator closely associated with overall cell proliferation. As depicted in Fig.9(A), following the initial laser welding, TGF-β secretion peaked in the 60° laser group, approximating 300 pg/ml. This suggests that a low-energy laser at a 60° incident angle could effectively activate the inflammatory response stage, stimulate M2 macrophage activity, and trigger an ample secretion of TGF-β2 factor, thereby catalyzing fibroblast proliferation. Although the healing process in the 60° laser group showed no significant improvements after the first laser treatment, it established a solid foundation for collagen skeleton regeneration in subsequent stages. The TGF content in the 90° laser group was almost equivalent to that in the 30° laser group (~200pg/ml). Following the second laser welding, the TGF levels across all groups displayed similar rankings, albeit decreased, indicating the onset of the re-epithelialization stage of healing. By day 14, the TGF level within the control group began to rise gradually, while the remaining three groups nearly returned to their normal levels. However, the TGF level in the 90° laser group remained at around 200pg/ml, suggesting a potential recurrence of scarring.