Experimental Study of the Effect of Photobiomodulation Therapy on the Regulation of the Healing Process of Chronic Wounds

Figure 5

Animal wound sites: 1: control group ((a) on day 3, among fibrins, there are numerous polymorphonuclear leukocytes, single fibroblasts, and collagen fibers; (b) on day 7, young granulation tissue with a moderate number of polymorphonuclear leukocytes, fibroblasts and blood vessels, and chaotic collagen fibers; (c) on the 14th day, granulation tissue with signs of maturation in the form of parallel orientation and thickening of collagen fiber bundles, the presence of fibrocytes, and single vessels; (d) on the 28th day, the newly formed dermis); 2: experimental group ((a) on day 3, young granulation tissue with a moderate number of fibroblasts and polymorphonuclear leukocytes, randomly located collagen fibers, and numerous vessels; (b) on day 7, granulation tissue with a moderate number of fibroblasts, numerous vessels, and parallel bundles of collagen fibers; (c) on the 14th day, maturing granulation tissue with parallel bundles of collagen fibers, fibrocytes, and single vessels; (d) on the 28th day, the newly formed dermis with dense bundles of collagen fibers) (H&E, ×400, scale bar 50 μm).