Changes in the cellular composition of the inflammatory infiltrate and connective tissue of the oral mucosa in rats during wound healing using a protective piezoelectric coating

Abstract

Introduction. Wound healing is a process based on a complex mechanism of intercellular interaction. The aim was to study changes in the oral mucosa cellular composition during wound healing with and without a protective piezoelectric coating. Materials and methods. The study was carried out on 50 Wistar rats divided into four groups: one control group of intact rats and experimental groups 1, 2, and 3. The rats of the experimental groups were subjected to excision of a lip mucous membrane flap with wound formation. In the animals of experimental group 1, the defect was open. In group 2, we used a polymer membrane with copper modification, and in group 3, the membrane was without copper modification. The animals were sacrificed on days 3, 7, and 12 of the study. We used light and electron microscopy to study the qualitative and quantitative changes in the composition of cell populations at the site of the defect. Results. On day 3, there prevailed neutrophilic infiltration in all groups. In groups 2 and 3, we observed a large number of macrophages and fibroblasts that indicated the transition to the next phase of wound healing. On day 7, in group 1, there persisted extensive neutrophilic and macrophage infiltration, whereas, in groups 2 and 3, the signs of inflammation decreased, and wound healing was active. On day 12, in group 1, all values were significantly higher than in the control group and there was damage to the ultrastructure; in groups 2 and 3, all the studied parameters reached the control values. Conclusion. We revealed the patterns of changes in the cellular composition of a wound during its healing. The use of the coating contributed to accelerated wound healing, which was found during the analysis of changes in the composition of cell populations. The closure of the oral mucosa wounds with polymer piezoelectric membranes was proven to have a good effect on tissue repair and was supposed to reduce the risk of postoperative complications. Keywords: wound defect, mucous membrane, oral cavity, piezoelectrics, inflammation, regeneration, scaffolds, dentistry