Profilaktika razvitiya fibroza pri regeneracii ranevyh defektov slizistoj obolochki polosti rta yavlyaetsya aktual'noj problemoj v sovremennoj hirurgicheskoj stomatologii. Cel'yu issledovaniya bylo provesti morfologicheskuyu ocenku vliyaniya biosovmestimyh p'ezoelektricheskih membran na formirovanie fibroznoj tkani v processe regeneracii ran slizistoj obolochki polosti rta. Byli proanalizirovany mezhkletochnoe vzaimodejstvie makrofagov i fibroblastov, a takzhe izmeneniya urovnya ekspressii markerov CD68 i TGFβ 1 i ih vliyanie na razvitie fibroza v usloviyah ispol'zovaniya biosovmestimyh polimernyh membran s p'ezoelektricheskimi svojstvami na razlichnyh etapah regeneracii ranevogo defekta slizistoj obolochki polosti rta. Provedena sravnitel'naya morfologicheskaya ocenka struktur slizistoj obolochki rotovoj polosti u zhivotnyh s intaktnoj slizistoj obolochkoj (n = 15), s otkrytym ranevym defektom (n = 15) i ranoj, perekrytoj biosovmestimoj p'ezoelektricheskoj membranoj (n = 15). Zabor materiala iz oblasti ranevogo defekta osushchestvlyali na 3-i, 7-e i 12-e sutki eksperimenta, v analogichnye sroki otbirali material u intaktnyh zhivotnyh. V gruppe s ispol'zovaniem biosovmestimoj membrany v oblasti defekta vyyavleny priznaki stadii proliferacii uzhe na 3-i stuki issledovaniya, bolee bystraya smena makrofagal'noj infil'tracii na fibroblasticheskuyu, snizhenie vospalitel'noj reakcii — na 7-e sutki i vosstanovlenie chislennoj plotnosti makrofagov i fibroblastov do intaktnyh znachenij — na 12-e sutki. Vyrazhennost' ekspressii markerov, prognoziruyushchih razvitie fibroza, CD68 i TGFβ1, byla nizhe, chem v gruppe bez ispol'zovaniya membrany. Nablyudali umen'shenie udel'noj ploshchadi plotnoj voloknistoj soedinitel'noj tkani na mikroskopicheskom urovne i vyrazhennost' deformacii myagkih tkanej na makroskopicheskom urovne. V gruppe bez ranevogo pokrytiya na vsem protyazhenii eksperimenta sohranyalis' obshirnaya kletochnaya infil'traciya i usilennaya ekspressiya CD68 i TGFβ1, chto privodilo k preobladaniyu udel'noj ploshchadi plotnoj voloknistoj soedinitel'noj tkani nad ryhloj soedinitel'noj tkan'yu na 12-e sutki issledovaniya i rubcovoj deformacii myagkih tkanej.

Prevention of fibrosis during the oral mucosal wound regeneration is a pressing issue of today’s surgical dentistry. The study was aimed to perform morphological assessment of the effects of biocompatible piezoelectric membranes on fibrous tissue formation during regeneration of the oral mucosal wounds. We assessed cell–cell interactions of macrophages and fibroblasts, along with changes in the CD68 and TGFβ1 marker expression and their effects on the development of fibrosis under conditions of using biocompatible polymeric membranes with piezoelectric properties at various stages of the oral mucosal wound defect regeneration. Comparative morphological assessment of the oral mucosal structures was conducted in animals having intact mucosa (n = 15), having open wound defects (n = 15), and having wounds covered with biocompatible piezoelectric membranes (n = 15). Biomaterial was collected from the wound defect site on days 3, 7, and 12 of the experiment; collection of biomaterial from intact animals was performed on the same days. In the group, where biocompatible membranes were used, signs of proliferation phase at the defect site were detected as early as on day 3 of the study; the faster shift from macrophage infiltration to fibroblast infiltration, the decline in inflammatory response were detected on day 7; restoration of the numerical density of macrophages and fibroblasts to the intact values was detected on day 12. The expression of CD68 and TGFβ1, the prognostic markers of fibrosis, was lower in the group, where no membranes were used. Reduction of the dense fibrous connective tissue specific area was observed at the microscopic level, severe soft tissue deformation was reported at the macroscopic level. In the group with no wound covering, extensive cell infiltration and increased CD68 and TGFβ1 expression persisted throughout the experiment, which resulted in the fact that specific area of dense fibrous connective tissue was larger, than that of loose connective tissue, on day 12 of the study, as well as in the cicatricial soft tissue deformities.

We studied restoration of microvessels in the oral mucosa wound defects under a polymer piezoelectric membrane (group 2) and without it (group 1). The control group included animals with intact mucosa. On day 3, the expression of the vascular endothelial growth factor (VEGF) increased in all experimental groups, while the expression of CD34 increased only in group 2, which attested to intensive neoangiogenesis. On day 7, we observed a decrease in VEGF expression and an increase in CD34 expression that was more pronounced in group 2, which reflected the beginning of blood vessels maturation. More rapid formation and maturation of blood vessels in group 2 was confirmed by electron microscopy: on day 7, endothelial cells with mature organelles and signs of active transcapillary exchange were seen. On day 12, the immature blood vessels still predominated in group 1, while in group 2, the expression of angiogenesis markers decreased though remained above the control, which created prerequisites for the complete restoration of wound area vascularization in group 2. In group 1, the expression of VEGF and CD34 was significantly below the control, which attested to the development of poorly vascularized scar tissue.

Wound defects of the oral mucosa are a common pathology the treatment of which often involves synthetic membranes. Development of varieties of such membranes is an ongoing process. This study aimed to register morphological features of the oral mucosa regeneration process in the presence of one of the varieties, the polymer piezoelectric membranes. The study involved 45 Wistar rats divided into 3 groups: 1) animals with an open wound defect; 2) animals with a wound defect covered with a copper-coated polymer membrane; 3) intact animals. The samples for morphometric study were collected on the 3rd, 7th and 12th days. On the 3rd day, rats of group 1 had the specific area of granulation tissue 1.4 times greater than that in group 2 (p = 0.033). In group 1 rats, endotheliocytes expressed more VEGF than in the animals of group 2. In group 2, the defect was ultimately completely covered with the epithelial layer, which was not the case in group 1. On the 7th day, the epithelium in rats of group 2 was twice as thick as the layer registered in group 1 (p = 0.019). Granulation tissue was replaced by loose fibrous connective tissue. In group 1, the specific area of inflammatory infiltration was greater than that of loose fibrous connective tissue, and the VEGF expression level was lower than in group 2. On the 12th day, the predominant tissue in group 2 was the loose fibrous connective tissue, the VEGF expression level equaled that of group 3, and peripheral nerves began to grow. In group 1, the specific area of dense fibrous tissue was 3.9 times greater than that in group 2 (p = 0.012), the epithelium had pathological changes and the VEGF expression was below control values. Thus, a polymer piezoelectric membrane had a positive effect on the post-wound restoration of the oral mucosa tissues.

Ranevye defekty slizistoj obolochki rta yavlyayutsya rasprostranennoj patologiej, dlya lecheniya kotoroj razrabatyvayut pokrovnye membrany. Cel'yu issledovaniya bylo izuchit' morfologicheskie osobennosti regeneracii slizistoj obolochki rta pri primenenii polimernyh p'ezoelektricheskih membran. Issledovanie provedeno na 45 krysah Wistar, razdelennyh na gruppy: 1) zhivotnye s otkrytym ranevym defektom; 2) zhivotnye s ranevym defektom, perekrytym polimernoj membranoj s mednym napyleniem; 3) intaktnye zhivotnye. Zabor materiala dlya morfometricheskogo issledovaniya provodili na 3-i, 7-e i 12-e sutki. Na 3-i sutki v gruppe 1 udel'naya ploshchad' granulyacionnoj tkani byla v 1,4 raza bol'she, chem v gruppe 2 (r = 0,033). Endoteliocity ee sosudov ekspressirovali VEGF v bol'shej stepeni v gruppe 2. V gruppe 2 proiskhodilo polnoe perekrytie defekta epitelial'nym plastom v otlichie ot gruppy 1. Na 7-e sutki v gruppe 2 epitelij byl v 2 raza tolshche, chem v gruppe 1 (p = 0,019). Granulyacionnaya tkan' zameshchalas' ryhloj voloknistoj soedinitel'noj tkan'yu. V gruppe 1 preobladala udel'naya ploshchad' vospalitel'noj infil'tracii nad ryhloj voloknistoj soedinitel'noj tkan'yu, ekspressiya VEGF byla nizhe, chem v gruppe 2. Na 12-e sutki v gruppe 2 preobladala ryhlaya voloknistaya soedinitel'naya tkan', ekspressiya VEGF ne otlichalas' ot gruppy 3, otmechalos' prorastanie perifericheskih nervov. V gruppe 1 udel'naya ploshchad' plotnoj voloknistostoj tkani byla v 3,9 raz bol'she, chem v gruppe 2 (r = 0.012), v epitelii imelis' patologicheskie izmeneniya, a ekspressiya VEGF byla nizhe kontrol'nyh znachenij. Takim obrazom, ispol'zovanie polimernoj p'ezoelektricheskoj membrany blagopriyatno vliyalo na vosstanovlenie tkanej slizistoj obolochki polosti rta v oblasti ranevogo defekta.

Introduction. Restoration of blood supply to tissues is crucial for the regeneration of wound defects. The purpose of this research was to study the effect of piezoelectric polymers on the restoration of microcirculation and hemodynamics in the area of oral mucosa wound defects. Materials and methods. The study was carried out on 60 Wistar rats divided into four groups (15 rats each): control (intact) and 3 experimental groups. In group 1, the animals had an open wound defect. In groups 3 and 2, the rats had a wound defect covered with a membrane with and without copper modification, respectively. The specimens for subsequent light and electron microscopy were collected on days 3, 7, and 12. We studied qualitative and quantitative indicators of microcirculation and hemodynamics restoration. Results. Day 3: in all experimental groups, the arteriolo-venular relationship and the pericapillary diffusion index significantly decreased, while the Kernogan index increased. We also observed a significant increase in VEGF expression. Day 7: in experimental group 3, the values of the Kernogan index and the arteriolo-venular relationship were restored, and the pericapillary diffusion index remained significantly higher than in the control group. In the groups 1 and 2, none of the indicators reached the control values. VEGF expression decreased in all groups. On day 12 in group 1, the arteriolo-venular relationship, the Kernogan index and the index of pericapillary diffusion differed from the control group, in contrast to groups 2 and 3, where all the studied parameters were restored. Expression of VEGF in group 1 was significantly less than the control values, and in groups 2 and 3 it was significantly higher. Conclusion. We revealed that closing of oral mucosa wound defects by a piezoelectric polymer membrane led to the restoration of hemodynamic parameters and promoted active vascular formation. Keywords: wound defect, oral cavity, inflammation, regeneration, microcirculation, neoangiogenesis

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

The aim of research is to study morphofunctional reorganization of the oral mucosa during regeneration of a wound defect using polymer membranes based on a copolymer of vinylidene fluoride with and without tetrafluoroethylene. Material and methods. The study included 35 white Wistar rats weighed 220–280 g. All animals were divided into three groups: group 1 – intact animals, group 2 – an experimental comparison group, and group 3 – an experimental main group. A wound defect in rats was formed by the excision of the mucosal flap in rats; this defect was overlapped by a polymer membrane in animals of the 3rd group. Histological and macroscopic studies were performed in 3, 7 and 12 days. Results. More rapid development of the granulated and loose fibrous connective tissue noted already on the 3rd day of the study was recorded in animals of the 3rd group. On the 7th day of the study a 1.5-time decrease in inflammatory infiltrate was recorded in animals of the experimental main group, while in the experimental comparison this indicator decreased in only 1.35 times. Moreover, the formation of the loose fibrous connective tissue in the main experimental group occurred 3.2 times more intensively than in the comparison group. On the 12th day, the specific area of the loose fibrous connective tissue in the experimental main group was 1.4 times larger, and the specific area of scar tissue was 3 times smaller than in the experimental comparison group. Conclusion. Application of polymer membrane demonstrated a decrease in inflammatory infiltrate and more rapid maturation of the loose fibrous connective tissue compared with the open wound  management. Moreover, there was a significantly smaller formation of the dense fibrous connective  tissue. Thus, it is possible to conclude on the effectiveness of polymer piezoelectric membrane application in the management of oral wound.

The aim of research is to study morphofunctional reorganization of the oral mucosa during regeneration of a wound defect using polymer membranes based on a copolymer of vinylidene fluoride with and without tetrafluoroethylene. Material and methods. The study included 35 white Wistar rats weighed 220–280 g. All animals were divided into three groups: group 1 – intact animals, group 2 – an experimental comparison group, and group 3 – an experimental main group. A wound defect in rats was formed by the excision of the mucosal flap in rats; this defect was overlapped by a polymer membrane in animals of the 3rd group. Histological and macroscopic studies were performed in 3, 7 and 12 days. Results. More rapid development of the granulated and loose fibrous connective tissue noted already on the 3rd day of the study was recorded in animals of the 3rd group. On the 7th day of the study a 1.5-time decrease in inflammatory infiltrate was recorded in animals of the experimental main group, while in the experimental comparison this indicator decreased in only 1.35 times. Moreover, the formation of the loose fibrous connective tissue in the main experimental group occurred 3.2 times more intensively than in the comparison group. On the 12th day, the specific area of the loose fibrous connective tissue in the experimental main group was 1.4 times larger, and the specific area of scar tissue was 3 times smaller than in the experimental comparison group. Conclusion. Application of polymer membrane demonstrated a decrease in inflammatory infiltrate and more rapid maturation of the loose fibrous connective tissue compared with the open wound management. Moreover, there was a significantly smaller formation of the dense fibrous connective tissue. Thus, it is possible to conclude on the effectiveness of polymer piezoelectric membrane application in the management of oral wound.