Mast cells of atrophic scar on exposure to inorganic gels and vascular endothelial growth factor in experiments

Abstract

BACKGROUND: Atrophic scars and their treatment are an understudied problem because research efforts traditionally concentrated on keloid and hypertrophic scars. One of the key roles in the development of atrophic scars can be played by mast cells, which may influence the treatment of atrophic scars. THE AIM: To quantitatively assess connective tissue mast cells in the model of atrophic scar under experimental application of inorganic gels and biocomposite with vascular endothelial growth factor (VEGF). MATERIALS AND METHODS: The study was carried out on 36 male Wistar rats. They were distributed into 6 groups: I, intact animals; II, controls; group III, application of VEGF; group IV, aluminum hydroxide gel application; V, silicone gel; VI, biocomposite based on aluminum hydroxide and VEGF. RESULTS: The numerical density of mast cells in all groups was significantly lower than that in intact skin, and the level of degranulation was significantly higher. The highest proportion of fully degranulated mast cells was observed in the atrophic scar model without experimental application. When VEGF was applied, partial degranulation of paravasal mast cells occurred. Under the influence of inorganic gels, the dermal structures of the scar recovered, which was also associated with the partial degranulation of mast cells. After silicone gel application, accumulations of partially degranulated mast cells were noted in the deep zones of the scar; after the application of aluminum hydrogel, they were found in the subepidermal layer. The experimental application of biocomposite combined the effects of VEGF and aluminum hydroxide application. Quantitative and qualitative characteristics of mast cells and the degree of their degranulation can be a criterion for assessing the effectiveness of local administration of biologically active substances in atrophic scarring. CONCLUSION: The restoration of the components of the intercellular substance of the dermis of an atrophic scar and growth of the synthetic activity of fibroblasts under the influence of inorganic gels was associated with degranulation and growth of mast cells. After the experimental application of polysiloxanes, the regeneration process captures deeper zones of the scar, and in the group that received aluminum hydrogel, more superficial zones were covered. After the local application of VEGF solution in phosphate buffer, partial degranulation of paravasal dermal mast cells was noted. Experimental application of the biocomposite combined the effects of the experimental application of aluminum hydrogel and VEGF. The abovedescribed effects were mediated by the epithelium of the atrophic scar.