Репозиторий Университета

© 2020 by the authors. The success of using soft tissue transplants is enough for their spreading in the clinic, but the need to cover the surface, where the transplant was taken from, can be forgotten. It can lead to long-term discomfort of the patient in real life, in some cases to complications alike bleeding; We performed the analysis of the use of different new xenogenic resorbable membranes created within our University in compare with the natural healing of oral mucosa defects in the experiment in vivo on 36 rabbits after performing of the surgical wound on the palatine side (5x5 mm). All animals were separated (divided) for 3 groups: #1 group of control and main groups #2 and #3, where we used pericardium and collagen film for covering mucous defects. We assessed the edema, hyperemia in the operation side, the pain according to animal behavior, the histological picture after animals completion of the experiment (on 3rd, 6th and 10th days); The decrease of clinical signs of inflammation in groups of collagen and pericardium films use (p<0.05) was statistically confirmed. Analysis of histologic investigation of biopsy specimens has shown the faster and massive growth of soft tissue in the donor site after application of pericardium and collagen films (p<0.05). An analysis of the experiment results allows recommending their possible use for closing the donor site after taking a free gingival graft or in the zone of postoperative wound defect in the oral mucosa in clinical oral surgery after specific clinical trials.

© 2019 Elsevier B.V. Application of restructured collagen-based biomaterials is generally restricted by their poor mechanical properties, which ideally must be close to those of a tissue being repaired. Here, we present an approach to the formation of a robust biomaterial using laser-induced curing of a photosensitive star-shaped polylactide. The created collagen-based structures demonstrated an increase in the Young's modulus by more than an order of magnitude with introduction of reinforcing patterns (from 0.15 ± 0.02 MPa for the untreated collagen to 51.2 ± 5.6 MPa for the reinforced collagen). It was shown that the geometrical configuration of the created reinforcing pattern affected the scaffold's mechanical properties only in the case of a relatively high laser radiation power density, when the effect of accumulated thermomechanical stresses in the photocured regions was significant. Photo-crosslinking of polylactide did not compromise the scaffold's cytotoxicity and provided fluorescent regions in the collagen matrix, that create a potential for noninvasive monitoring of such materials' biodegradation kinetics in vivo.

© 2018 by the authors. The aim of the study was to investigate the effects of several decalcifying agents used as irrigant solutions in endodontic treatment on collagen and mineral components of dentin. Coronal dentin discs from five caries-free human third molars with a smear layer were treated for one minute with a chelating solution (1% Ethylenediaminetetraacetic acid (EDTA), 10% EDTA, 17% EDTA, 10% citric acid). Mineralization degree (Ca/N and P/N atomic ratios, IR Iapatite/Iamide II and I1410(carbonate)/I554(phosphate) spectroscopic ratios) and possible collagen rearrangements (collagen infrared (IR) amide II e III shifts) were evaluated by environmental scanning electron microscopy (ESEM)/energy dispersive X-ray spectroscopy (EDX) and IR spectroscopy before and after treatment (T0) and after ageing (T24h and T2m) in simulated body fluid (SBF). At T0, analysis showed that the highest demineralizing effect was achieved using a 10% citric acid solution and 10% EDTA, while the smallest effect was observed when using 17% EDTA. No significant collagen modifications were detected upon treatment with 1% EDTA, while subtle changes were observed after the other treatments. At T24h or T2m, analyses showed the highest remineralization values for 1% EDTA and the lowest for 10% citric acid, mainly at T2m. The samples treated with 17% EDTA showed slight collagen rearrangements upon remineralization. In conclusion, the highest demineralizing effect was observed for 10% EDTA and 10% citric acid. Collagen rearrangement was found for all the treatments except for 1% EDTA. The highest remineralization capability in SBF values was recorded for 1% EDTA and the lowest for 10% citric acid. A slight collagen rearrangement upon remineralization was still present in 17% EDTA-treated samples. Clinical use as a chelating agent in the endodontic therapy of citric acid and concentrated EDTA solutions should be reconsidered.

© 2018, Springer Science+Business Media, LLC, part of Springer Nature.  New composite materials of collagen with electrical conductivity up to 6.1•10 –4 S cm –1 were obtained using colloidal dispersions of polyvinylpyrrolidone-stabilized graphene.

© 2018 Elsevier GmbH Background: The non-healing wound is a characteristic clinical sign in recessive dystrophic epidermolysis bullosa (RDEB). Methods: Six patients with recessive dystrophic epidermolysis bullosa were injected with suspension of allogeneic fibroblasts into erosion margins. Erosions (>1 month old) with surface area between 2 cm2 and 28 cm2 were selected for treatment. The patients were administered with 1 mL suspension of allogeneic fibroblasts with concentration 5 × 106 cells/ml, 10 × 106 cells/ml and 20 × 106 cells/ml. Paired erosions were injected with vehicle solution alone. All erosions were assessed for healing rate and biopsied at baseline and at two weeks after treatment. Immunofluorescence antigen mapping (IFM) was performed to detect C7 expression. Results: An increase of healing rate was detected 14 days after fibroblasts and vehicle alone injections, in some cases with complete erosion closure. The results of the IFM in patients treated with allogeneic fibroblasts and vehicle solution demonstrated the increase of collagen VII expression in dermo-epidermal junction, more intensive in patients injected with 20 × 106 cells/ml. Conclusions: Intradermal administration of allogeneic fibroblasts is a safe and effective method of treatment of non-healing wounds in recessive dystrophic epidermolysis bullosa.

© 2018, Springer Science+Business Media, LLC, part of Springer Nature. We created an anisotropic material based on collagen sponge and reactive polylactide structured by laser photopolymerization. The combination of collagen with reactive polylactide improves the resistance of the formed matrices to biodegradation in comparison with collagen sponge, while the existence of sites with different mechanical characteristics and cell affinity on the matrix provides directed cell growth during their culturing. It was shown that reinforcement of the collagen sponges 7-fold increased the mean Young’s modulus for the hybrid matrix without affecting its cytotoxicity. The developed matrix provides cell adhesion and proliferation along reinforcement lines and can be used for fabrication of tissue engineering constructs.

© 2018 Tong, Lönnblom, Yau, Nandakumar, Liang, Ge, Viljanen, Li, Bãlan, Klareskog, Chagin, Gjertsson, Kihlberg, Zhao and Holmdahl. Background: Collagen XI (CXI) is a heterotrimeric molecule with triple helical structure in which the a3(XI) chain is identical to the a1(II) chain of collagen II (CII), but with extensive posttranslational modifications. CXI molecules are intermingled in the cartilage collagen fibers, which are mainly composed of CII. One of the alpha chains in CXI is shared with CII and contains the immunodominant T cell epitope, but it is unclear whether there are shared B cell epitopes as the antibodies tend to recognize the triple helical structures. Methods: Mice expressing the susceptible immune response gene Aq were immunized with CII or CXI. Serum antibody responses were measured, monoclonal antibodies were isolated and analyzed for specificity to CII, CXI, and triple helical collagen peptides using bead-based multiplex immunoassays, enzyme-linked immunosorbent assays, and Western blots. Arthritogenicity of the antibodies was investigated by passive transfer experiments. Results: Immunization with CII or CXI leads to a strong T and B cell response, including a cross-reactive response to both collagen types. Immunization with CII leads to severe arthritis in mice, with a response toward CXI at the chronic stage, whereas CXI immunization induces very mild arthritis only. A series of monoclonal antibodies to CXI were isolated and of these, the L10D9 antibody bound to both CXI and CII equally strong, with a specific binding for the D3 epitope region of a3(XI) or a1(II) chain. The L10D9 antibody binds cartilage in vivo and induced severe arthritis. In contrast, the L5F3 antibody only showed weak binding and L7D8 antibody has no binding to cartilage and did not induce arthritis. The arthritogenic L10D9 antibody bound to an epitope shared with CII, the triple helical D3 epitope. Antibody levels to the shared D3 epitope were elevated in the sera from mice with arthritis as well as in rheumatoid arthritis. Conclusion: CXI is immunologically not exposed in healthy cartilage but contains T and B cell epitopes cross-reactive with CII, which could be activated in both mouse and human arthritis and could evoke an arthritogenic response.

© Microscopy Society of America 2018. Radiation therapy, widely used in the treatment of a variety of malignancies in the pelvic area, is associated with inevitable damage to the surrounding healthy tissues. We have applied atomic force microscopy (AFM) to track the early damaging effects of ionizing radiation on the collagen structures in the experimental animals' bladder and rectum. The first signs of the low-dose radiation (2 Gy) effect were detected by AFM as early as 1 week postirradiation. The observed changes were consistent with initial radiation destruction of the protein matrix. The alterations in the collagen fibers' packing 1 month postirradiation were indicative of the onset of fibrotic processes. The destructive effect of higher radiation doses was probed 1 day posttreatment. The severity of the radiation damage was proportional to the dose, from relatively minor changes in the collagen packing at 8 Gy to the growing collagen matrix destruction at higher doses and complete three-dimensional collagen network restructuring towards fibrotic-type architecture at the dose of 22 Gy. The AFM study appeared superior to the optical microscopy-based studies in its sensitivity to early radiation damage of tissues, providing valuable additional information on the onset and development of the collagen matrix destruction and remodeling.

© 2018 Hubail et al. Purpose: The aim of this study was to evaluate the progression of a case of a patient with epidermolysis bullosa (EB) since early age who survived to adulthood, presenting with recurrent skin blisters and disfiguring scars and disabling musculoskeletal deformities. Background: EB is a rare group of inherited diseases that affect the skin fragility causing it to blister in response to even minor trauma. Established novel treatments are limited in the literature due to its rarity, and more research is needed to set a global management approach. Clinical manifestations range widely from localized to generalized blistering. Methods: A rare case of EB surviving to adulthood despite the complications, which has been evaluated, treated during a relapse, and followed up. Conclusion: The described case is of considerable clinical interest due to its rarity and severity. Optimal management requires a multidisciplinary approach and revolves around the protection of the skin against slightest injury, use of careful wound care dressings, aggressive nutritional support, and early medical or surgical interventions if needed to manage any complications. Prognosis varies considerably depending on each case.

© 2018 American Leather Chemists Association. All rights reserved. The regenerative potential of biodegradable collagen matrix (hemostatic sponge) for healing full-thickness rabbit conjunctival injury was studied. Results of histological investigation and scanning electron microscopy showed evidence of the progressive degradation of collagen matrix followed by granulation tissue formation from periphery to the center of the conjunctival wound. The ungrafted conjunctival defect was substituted with granulation tissue from the intact edges of wound to the center. Both matrix-grafted and ungrafted full-thickness conjunctival defects were covered completely with loose stroma and stratified squamous epithelium within 30 days. Thus, high regenerative potential of biodegradable collagen matrix (hemostatic sponge) implanted into the zone of injury for healing full-thickness defect of rabbit conjunctiva was established.

© 2018 Izdatel'stvo Meditsina. All rights reserved. The healing process in the adult rabbit conjunctiva and sclera tissues after translimbal microdrainage with the use of either biodegradable antiglaucomatous drainage (BDAD) or iGen was studied. Wound areas showed similar acute inflammatory response to the implantation of both matrixes on the 7th day. Complete lysis degradation of iGen and BDAD was observed on 30th day and 60th day, respectively. Within 60 - 90 days after BDAD implantation, the wound areas of conjunctiva and sclera showed intensive angiogenesis and poor extracellular matrix scarring. In contrast, on the 90th day after iGen implantation, a decrease in angiogenesis and intensive extracellular matrix scar formation were observed. As a result of scarring the thin-walled vessels were compressed, which led to the reduction of aqueous humor outflow.

© 2018 Vserossiiskoe Obshchestvo Kardiologov. All rights reserved. Aim. To evaluate the role of N-terminal procollagen type III propeptide (P3NP) as a proposed marker of myocardial fibrosis in type 2 diabetes (DM2) patients. Material and methods. In the study, 2 groups of patients participated: with DM2 and non-DM2 (both n=32). All patients underwent clinical and laboratory assessment, including P3NP, electrocardiography, echocardiography. Statistics was done with Mann-Whitney criteria and Spearman correlation. Results. The level P3NP is significantly higher in DM2 patients (р<0,00001). In DM2 patients, the level of P3NP significantly correlates with increased myocardial mass of the left ventricle (р=0,00026) and myocardial mass index of the left ventricle (р=0,03685). Conclusion. Echo- and electrocardiographic signs characteristic for myocardial fibrosis (mass increase, voltage decline) in DM2 patients are concomitant with the increase of P3NP. Significant correlation of P3NP and the size of myocardium makes it to propose P3NP as one of possible markers of myocardial fibrosis in DM2 persons.

© Bionika Media Ltd. Different factors caused by both equipment and the course of surgery (conditions under which the operation is performed, the location of incision, the characteristics of suture material, the type of surgical suture, and the amount of blood loss), by the course of the postoperative period, and the peculiarities of repair of damaged tissues influence wound healing of the uterus during cesarean section. Objective. To establish the value of premature amniorrhea and uterine inertia as predictors of impaired myometrial repair after cesarean section, by using clinical and morphological analyses. Subjects and methods. The investigation enrolled 129 patients who had given birth via cesarean section. Of them, 44 patients had delivery before birth activity, 85 during the first stage of labor. 49 and 80 women delivered before and after amniorrhea, respectively. During cesarean section, uterine tissue was taken from the upper edge of the wound after uterine incision. The myometrial biopsy specimens obtained during cesarean section were morphologically and immunohistochemically examined. The patients were divided into 4 groups according to the level of birth activity and the preservation of amniotic fluid at the time of cesarean section. Group 1 included patients with regular labor activity and amniorrhea at the time of caesarean section; Group 2 consisted of those with labor activity in the presence of whole amniotic fluid; Group 3 comprised those without birth activity in the presence of whole amniotic fluid; Group 4 included patients with premature amniorrhea without uterine contractions. 36 cases (9 in each group) were selected by random sampling for morphological and immunohistochemical examinations. The biopsy specimens were fixed in 10% neutral formalin and embedded in paraffin. The serial paraffin-embedded sections underwent histological examination and immunohistochemical tests for the following markers: TGF-β, VEGF, MMP2, TIMP1, types I and III collagen, TNF, and PDGF. Results. The morphological and immunohistochemical analyses revealed the most pronounced signs of myometrial damage during cesarean section in Group 4 patients having premature amniorrhea without uterine contractions. There were decreased VEGF, PDGF, MMP2, and TIMP levels and simultaneously increased TNF-α expression in leiomyocytes, vascular endothelium, and myometrial stromal cells. The findings may indicate the relatively lower reparative potential of the myometrium and the increased readiness for an inflammatory response in the group of women undergoing cesarean section in the presence of premature amniorrhea without uterine contractions. Conclusion. Clinical, morphological, and immunohistochemical analyses have revealed differences in the myometrial status in relation to typical clinical factors, such as amniorrhea and birth activity. Wound healing occurs under the influence of growth factors and the ratio of expression levels for growth factors can vary in different pathological conditions. The reduced expression of VEGF, MMP2, TIMP, and PDGF and the increased expression of TNF in the group having amniorrhea without uterine contractions (P-B+) suggest that there are pronounced inflammatory processes and impaired myometrial repair with the longer latency period in the absence of labor activity, which may refer these women to a group at risk for incompetent scar formation.

© 2018 SPIE. The technology of cell 3D scaffolds laser fabrication is developed. 3D scaffolds are designed to repair osteochondral defects, which are poorly restored during the organism's life. The technology involves the use of an installation, the laser beam of which moves along a liquid nanomaterial and evaporates it layer by layer. Liquid nanomaterial consists of the water-protein (collagen, albumin) suspension with carbon nanoparticles (single-walled carbon nanotubes). During laser irradiation, the temperature in the region of nanotubes defects increases and nanotubes are combined into the scaffold. The main component of installation is a continuous laser operating at wavelengh of 810 nm. The laser beam moves along 3 coordinates, which makes it possible to obtain samples of the required geometric shape. The internal and surface structure of the samples at the micro- A nd nanoscale levels were studied using the X-ray microtomography and scanning electron microscopy. In vitro studies of cell growth during 48 and 72 hours demonstrated the ability of cell 3D scaffolds to support the proliferation of osteoblasts and chondroblasts. Using fluorescence and atomic force microscopy, it was found that the growth and development of cells on a sample with a larger concentration of nanotubes occurred faster compared to samples with a smaller concentration of nanotubes.

AIM: To evaluate the efficacy and safety of collagen biomaterial application during the 4-week follow-up of patients with diabetic foot syndrome.MATERIAL AND METHODS: 75 patients with diabetic foot (Wagner II (69.3%) and III (30.7%)) aged 30-80 years were included in the multicenter study, among them were 50.7% with the wound unhealed for 1.5-6 months and 49.3% over 6-48 months. Patients were randomized into 2 groups: 1) standard therapy (n=37), 2) the additional use of the collagen material Collost (n=38). Observation period was at least 4 weeks for each patient. The size of ulcers, results of general and biochemical blood tests, oximetry, microbiological testing, ultrasound of lower extremities vessels as well as a detailed medical history, social and functional status, level of cardiovascular comorbidity and ongoing therapy were estimated.RESULTS: Additional use of a collagen biomaterial has led to a significant reduction ulcers of all sizes from 13.5 to 2.1 cm2 (in the comparison group - from 12.5 to 7 cm2). The best dynamics have been registered in Wagner II (4.4-fold average wound area regress in Collost group, from 8.8 to 2.0 cm2; average wound area regress by 1.8 times, from 10 to 5.6 cm2 in the comparison group) than in Wagner III group (in the main group from 55 to 21.3 cm2; in the control group from 36 to 32.4 cm2) and in ulcers existing less than 6 months. Treatment with biological material Collost within standard therapy after 4 weeks led to increase of complete epithelialization by 2.6% (21.1% as compared to 14.7%), while decreasing the frequency of ineffective treatment by 4.1 (7.9% in primary and 32.4% in the comparison group).CONCLUSION: We have proved the efficacy and safety of collagen biomaterial topical application in a diabetic foot syndrome treatment.

© 2018, Nizhny Novgorod State Medical Academy. All rights reserved. The aim of the study was to demonstrate a good diagnostic potential of atomic force microscopy (AFM) in tracking morphological changes in the extracellular matrix (ECM) of connective tissue due to pathological processes. Here we summarize our experience in AFM application in a number of biomedical studies on the connective tissue disease, both for the research and clinical purposes. Materials and Methods. Depending on the project application (experimental or clinical), the tissue specimens were harvested either from animals, or from patients in the course of their surgical treatment, or post mortem. AFM images of fixed tissue slices on glass slides were acquired with a Solver P47 AFM instrument (NT-MDT, Russia), in the semi-contact mode. For mechanical properties mapping, the images were acquired on air in the PeakForce Quantitative Nanomechanical Mapping mode (PeakForce QNM®), using a MultiMode 8 atomic force microscope (Bruker, USA). The regions of interest for scanning were selected in accordance with the histological assignments for the same sample, based on the view of a sample in the built-in optical microscope of the AFM instrument setup. To quantify the changes in the ECM morphology visualized by AFM imaging, we applied flicker-noise spectroscopy parameterization. Results. AFM has been shown to reveal visible deviations from the normal morphology of the ECM in diseased tissues. We found that AFM and related techniques are capable of tracking disease-related changes at different levels of collagen organization in the ECM. At the microscale, AFM may detect loosening and disorganization of collagen fibers (e.g., in a dysplastic process), or the opposite process of their packing into tight parallel bundles in a fibrotic process. AFM may also monitor the ratio between collagen and non-fibrous material of the ECM, for example, in inflammatory and neoplastic processes. At the level of collagen fibrils, AFM may reveal early signs of the matrix destruction and remodeling not visible at the microscopic level. The flicker-noise spectroscopy parameters provide quantification of the morphological changes visualized by AFM. The PeakForce QNM® and nanoindentation studies give a further insight into the state of ECM via tracking changes in the local mechanical and adhesive properties. All our AFM studies appeared in a good agreement with the histological findings and generally had a superior sensitivity to pathology-related ECM rearrangements. Conclusion. AFM may serve as a valuable complementary diagnostic tool for tracking pathological changes in the connective tissue.

© 2017 Astro Ltd. A two-photon laser femtosecond crosslinking process at the wavelength of 525 nm was studied in a human donor cornea in the presence of riboflavin using two-photon optical microscopy and nanoindentation. It was shown that such an approach results in efficient crosslinking of the corneal collagen and a significant (three-fold) increase in the Young's modulus of the corneal structure. Application of a femtosecond laser with the wavelength of 525 nm allows a drastic enhancement of efficiency in the presence of riboflavin on human corneas and a 50-fold reduction of the laser treatment duration in comparison with the use of a femtosecond laser with the wavelength of 760 nm. We relate this effect to a significant growth in the coefficient of two-photon absorption due to the laser wavelength falling within the edge of the photoinitiator (riboflavin) absorption band. Our studies on a donor human cornea demonstrate the good potential for the clinical application of a femtosecond laser with the wavelength of 525 nm for increasing the cornea rigidity using the two-photon laser femtosecond crosslinking technique.