Experimental study on stromal vascular fraction mediated inhibition of skin pigmentation in guinea pigs

Background: Pigment disorder dermatoses are common diseases with complex mechanisms. There are various methods for the clinical treatment of pigmentation diseases, but these have a poor curative effect and many adverse reactions. Currently, looking for safe and effective whitening agents is a popular research topic. Stromal vascular fractions (SVFs) are a compound cell component of adipose-derived stem cells (ADSCs) that can promote tissue regeneration, healing, and vascularization. The purpose of this experiment was to investigate the inhibitory effect of SVFs on pigmentation in guinea pigs.Methods: After guinea pig subcutaneous fat was digested and centrifuged, SVFs were isolated and quantified. SVF was injected into the pigmentation area of the prepared guinea pig pigmentation model. The amount of inducible nitric oxide synthase (iNOS) was determined using immunohistochemical analysis, histopathological staining, and the Fontana-Masson (F-M) method for measuring melanin formation.Results: The skin of the guinea pigs obtained stable and homogenous coloration following three treatments with narrow-band ultraviolet B (NB-UVB). Hematoxylin-eosin (HE) staining revealed that compared to the control group, the cuticle, granular layer, and spinous layer were thicker and the number of epidermal melanocytes and melanin granules increased. While the quantity of pigment granules in the treated group dramatically decreased, it did not significantly change in the blank control group. F-M staining revealed that melanin granules greatly expanded following ultraviolet irradiation and were continuously distributed in basal cells and spinous layers. The entire epidermis was evenly covered in melanin granules. The level of melanin dramatically decreased following therapy. According to immunohistochemical labeling, epidermal cells' cytoplasm and membranes are where iNOS is primarily found. In the epidermis of the irradiated group, iNOS expression was much higher than in the control group, and following treatment, it decreased in the experimental group.Conclusions: SVFs have a reliable treatment effect on ultraviolet B (UVB)-induced pigmentation in guinea pig skin. SVFs can significantly inhibit pigmentation, effectively shorten the fading time of pigmentation, and play a role in skin whitening, providing a new breakthrough for the treatment of pigmentation diseases.