Sun Yan, Tosa Mamiko, Takada Hiroya, Ogawa Rei
Department of Dermatology, The First Hospital of China Medical University.
Department of Plastic, Reconstructive and Aesthetic Surgery, Nippon Medical School.
J Nippon Med Sch. 2020;87(3):110-117. doi: 10.1272/jnms.JNMS.2020_87-301.
Cutaneous wound healing is a complex, dynamic physiological process. Traditional methods of promoting wound healing are not always effective. Consequently, alternative modalities, such as photodynamic therapy (PDT), are needed. We examined the effectiveness and underlying mechanisms of PDT in a murine model of acute wound healing.
Two excisional wounds were produced, one on each side of the midline, in C57bL/6J mice. Methyl 5-aminolevulinate hydrochloride (MAL) was applied to the right-side wound. After 1 to 3 hours of incubation, the wound was irradiated with red light. The left-side wound was not treated with MAL or red light. On Day 14, the wounds were excised and subjected to histological and immunohistochemical analysis.
During the first week, no difference was seen between the two sides. However, at week 2, PDT-treated wounds exhibited delayed re-epithelialization. On Day 14, hematoxylin and eosin (HE) staining showed a continuous epithelial lining in untreated wounds. In contrast, PDT-treated wounds partially lacked epithelium in the wound bed. Masson's Trichrome (MTC) staining showed a thicker dermis and more collagen fibers and inflammatory cells in PDT-treated wounds than in untreated wounds. Immunohistochemical analyses showed significantly fewer CD31 blood vessels and greater collagen III density in PDT-treated wounds than in untreated wounds. However, treated and untreated wounds did not differ in collagen I density.
PDT delayed acute wound healing in a murine model of secondary intention wound healing.
皮肤伤口愈合是一个复杂、动态的生理过程。传统的促进伤口愈合的方法并非总是有效。因此，需要诸如光动力疗法（PDT）等替代方法。我们在急性伤口愈合的小鼠模型中研究了PDT的有效性及其潜在机制。
在C57bL/6J小鼠的中线两侧各制造一个切除伤口。将盐酸5-氨基乙酰丙酸甲酯（MAL）应用于右侧伤口。孵育1至3小时后，用红光照射伤口。左侧伤口未用MAL或红光处理。在第14天，切除伤口并进行组织学和免疫组织化学分析。
在第一周，两侧未见差异。然而，在第2周时，接受PDT治疗的伤口上皮再形成延迟。在第14天，苏木精-伊红（HE）染色显示未处理的伤口有连续的上皮衬里。相比之下，接受PDT治疗的伤口在伤口床部分缺乏上皮。Masson三色染色（MTC）显示，与未处理的伤口相比，接受PDT治疗的伤口真皮更厚，胶原纤维和炎症细胞更多。免疫组织化学分析显示，与未处理的伤口相比，接受PDT治疗的伤口中CD31血管明显更少，胶原III密度更高。然而，处理过的伤口和未处理的伤口在胶原I密度方面没有差异。
在二期愈合伤口的小鼠模型中，PDT延迟了急性伤口愈合。
