Background/Objectives: The objective of this study was to assess the efficacy of a cell-containing wound dressing based on fibroblasts in hydroxyethylcellulose (HEC) gel for the local treatment of deep partial-thickness and/or full-thickness skin burns in an animal model. Methods: The rats (male Wistar, n = 100) were subjected to a full-thickness thermal burn (16 cm²). Radical necrectomy was performed one day after the burn. Three days later, the rats were randomly assigned to one of four groups: group 1 (no treatment), group 2 (chloramphenicol and methyluracil ointment, a routine clinical treatment), group 3 (a gel without cells, mock treatment), and group 4 (a dermal fibroblast-impregnated HEC gel). The treatment lasted for five days. The wound-healing process was evaluated by planimetric, cytologic, histologic, and immunohistochemical methods. Results: The differences in the rate of wound healing and the characteristics of wound cytology were identified. In the group 4, a regenerative type of cytogram was revealed, characterized by a significantly increased number of fibroblastic cells in comparison to samples from non-treated and mock-treated animals. Biopsy samples of burn wounds from animals in the group 4l demonstrated the presence of mature granulation tissue and a large number of microvessels. The repair process was stimulated, as evidenced by the increased thickness of newly formed granulation tissue and epidermis in the wound zone, elevated cellularity, and enhanced re-epithelialization activity. The number of Ki-67-positive proliferating cells was significantly higher in group 4 than in the control groups). A small number of non-proliferating donor fibroblasts was observed in the wound area 3 days after the end of treatment. Conclusions: The cell product is an effective agent for promoting wound healing during the regenerative phase. The experiments demonstrated that a gel populated by dermal fibroblasts can stimulate reparative regeneration processes in deep partial- and full-thickness burn wounds.

Background. Despite the wide range of studies, the development of osteoplastic material, which has not only osteoconductive but also osteoinductive properties, remains an extremely topical issue in modern medical materials science. This work is devoted to experimental evaluation of the effectiveness of synthetic osteoplastic composite material based on chitosan and hydroxyapatite. Aim. This study aimed to determine the effects of spongy implants based on chitosan and its composite with hydroxyapatite nanoparticles in an amount of 50 wt. % on early osteogenesis in the area of the through defect of the ileum. Materials and methods. The studied materials were sponge implants based on chitosan and its composite with hydroxyapatite nanoparticles in an amount of 50 wt. %. Comparison groups include those without implant placement and those with replacement with commercial Reprobone osteoplastic material. Materials were implanted into the zone of the through defect of the ileum of rabbits for a period of 28 days. Results. A high rate of resorption of materials based on chitosan in bone tissue and active growth of reticulofibrotic bone tissue along the edges of the defect was established, and the formation of cartilaginous islands and bone marrow was recorded in the group of chitosan implants with hydroxyapatite. The aseptic effect was observed with the use of implants made of chitosan and hydroxyapatite. Conclusions. The data obtained allow us to argue about the osteoconductivity of the studied materials and the prospects for further development in this direction.

BACKGROUND: Burns remain a crucial part of the structure of injuries in Russia and abroad. Therefore, providing high-quality medical care to burn victims is relevant. Despite the large number of proposed solutions to this condition, developments in the field of tissue engineering and medical materials science still lack standardization and consideration of specific features of animal burn models for their testing. Many studies showed minor and major disadvantages from a technical and descriptive point of view. AIM: To analyze and identify the main disadvantages of existing burn models to assess the effect of wound healing agents. MATERIALS AND METHODS: This article examines the search results in the databases Google Scholar and PubMed using the keywords “burns,” “rats,” “animal model,” and “wound healing.” Sixty publications were analyzed. RESULTS: Seven quality criteria for the animal burn model have been determined, which allow obtaining reliable results and reproducing the described experiment: indication of the terms of quarantine and conditions of keeping laboratory animals, detailed description of the technique of applying burn injury, presence of one burn on a laboratory animal, presence of a control biopsy, indication of the absolute value of the initial burn area, presence of surgical treatment of burn wounds, and correct use of formulas for the planimetric assessment of wound healing. CONCLUSIONS: A solution to the problem of creating a standardized model may be a more detailed description of techniques and following the proposed quality criteria.

BACKGROUND: In modern regenerative medicine, the development of personalized biomedical cellular products for the replacement of bone tissue defects is crucial. Such products consist of a cellular component, a scaffold designed to retain cells and provide mechanical support, and auxiliary components. In vitro experiments do not adequately assess the effects of these constructs on bone regeneration or on the systemic response of the recipient organism. AIM: This study aimed to determine the outcomes of implanting scaffolds based on polycaprolactone, hydroxyapatite, and dental pulp stem cells into jaw bone defects in rabbits. METHODS: The study was conducted in Soviet (Russian) Chinchilla rabbits (n = 10) weighing 3.5–4.5 kg and aged 1–1.5 years bred under vivarium conditions. Four teeth were extracted from each animal (40 teeth in total), then the animals were divided into 5 groups. The regenerative outcomes were assessed after 4 months. To evaluate differences in the extent and rate of defect healing, histopathological examination of the implantation sites was performed. The degree of fibrosis, inflammation, and bone tissue remodeling was assessed in hematoxylin and eosin–stained sections, whereas the distribution pattern of implanted cells labeled with iron oxide nanoparticles was evaluated using Perls’ staining. RESULTS: At the implantation sites, scaffolds (both cell-seeded and cell-free) accelerated bone defect remodeling and fibrosis without the formation of coarse scar tissue. The most favorable combination of outcomes—namely minimal inflammation, the most advanced stage of bone tissue remodeling, and mature connective tissue formation at the implantation site—was observed in the group receiving copper-coated polycaprolactone scaffolds seeded with dental pulp stem cells. CONCLUSION: The results confirm the promise of this approach for the development of bioengineered constructs for the reconstruction of bone defects.

BACKGROUND: Degenerative/dystrophic cartilage diseases are an epidemiologically important challenge in modern traumatology and orthopedics. The use of autologous mesenchymal stem cells to repair cartilage defects is currently the most promising treatment option. AIM: The aim of this paper was to review the literature on the use of adipose tissue-derived mesenchymal stem cells to repair articular cartilage defects in laboratory animals. MATERIALS AND METHODS: Recent and historical Russian and English literature was searched in Google Scholar, Cyberleninka, PubMed, eLibrary, Mendeley, Science Direct databases for over 20 years. A total of 113 papers were selected, and 25 papers that met the inclusion criteria were selected based on full-text materials and abstracts. RESULTS: Literature shows that autologous adipose-derived mesenchymal stem cells stimulate hyaline cartilage regeneration. The vast majority of studies show that the addition of both differentiated and undifferentiated cells accelerates cartilage repair, regardless of the composition of the vehicle matrix or gel. Adipose-derived mesenchymal stem cells can also be used as a stand-alone technology without any vehicles. CONCLUSIONS: There is still no ideal graft to restore cartilage tissue, despite a wide range of technologies, surgical techniques and materials for repairing cartilage defects. However, mesenchymal stem cells improve the rate of defect repair and may become a new therapeutic strategy for degenerative/dystrophic cartilage diseases.

Introduction Congenital scoliosis is a multifactorial disease caused by abnormalities in vertebral development during embryogenesis. The TBX6 gene, located at locus 16p11.2, plays a key role in somitogenesis, and the heterozygous deletion is associated with the development of specific phenotypes of congenital scoliosis (TBX6-associated congenital scoliosis, TACS). Despite numerous studies on the role of TBX6 in the pathogenesis of congenital scoliosis, there is a paucity of data on the phenotypic manifestationsof heterozygous 16p11.2 deletion.The objective was to identify and confirm the TACS phenotype being associated with 16p11.2 deletions in the Russian patients.Material and methods A single-center retrospective cohort study included 187 patients diagnosed with congenital scoliosis treated at the Turner National Medical Research Center for Pediatric Orthopedics and Traumatology between 2012 and 2021. Heterozygous deletion (16p11.2 region) were verified using MQRT‑PCR. The deletion group consisted of 42 patients, and the control group included 145 probands. Clinical and radiological findings were reviewed to identify localization, type and multiplicity of vertebral anomalies and associated malformations. Descriptive statistics and Pearson's correlation coefficient were used for data processing.Results Heterozygous deletion of TBX6 was detected in 22.4 % of patients. The thoracic and lumbar spine were common localizations, while involvement of the cervical spine was not identified in the deletion group. Vertebral malformations were the most common anomaly in both study groups, but their prevalence was higher among patients with TBX6 deletion (50 % vs. 43.4 %). Multiple spinal malformations were more common in the deletion group (50 % vs. 35 %). Associated internal organ defects were less common in patients with deletion (31 % vs. 43.4 %), while rib synostoses and Sprengel's disease were more common.Discussion TACS is characterized by specific manifestations including multiple vertebral malformations in the thoracic and lumbar spine, rib synostoses and Sprengel's disease, which is consistent with the scientific literature.Conclusion The findings indicate the need to include genetic testing for TBX6 deletion in the diagnostic algorithm for congenital scoliosis to facilitate early detection and a personalized approach to treatment of this cohort of patients.