Objective: To develop a detergent-enzymatic method and evaluate the quality of a decellularized pulp scaffold for regenerative endodontics.Materials and methods: Biomaterial and mesenchymal stem cells (MSCs) were derived from dental pulp that was obtained following third molar extraction indicated for orthodontic reasons in patients aged 14-18 years. The detergent-enzymatic method enabled to obtain a decellularized scaffold from pulp samples. The proliferative activity and viability of dental pulp-derived MSCs were assessed using trypan blue staining and XTT assay. To assess tissue response, Wistar rats underwent subcutaneous implantation of native and decellularized dental pulp. Explanted samples were stained with hematoxylin-eosin on days 7 and 14.Results: The detergent-enzymatic treatment of the dental pulp demonstrated the absence of nuclear material, whereas the histoarchitecture of the dental pulp was disturbed. The DNA content in the sample of the decellularized scaffold was 22.79 ± 2.1 ng/mg of tissue; the amount of DNA in the native sample was 78.5 ± 5.4 ng/mg of tissue. According to XTT assay results, no cytotoxicity of the decellularized scaffold against MSCs was found. Biopsy specimens of the rats with implanted decellularized dental pulp were characterized by no signs of inflammation.Conclusions: The study results will enable to create a biomaterial that can be the base of a tissue-engineered structure of the dental pulp and be used for the regeneration of the pulp-dentin complex.

The problem with modern nerve conduits is inability to transmit nerve impulses to the distal part of the damaged nerve. Cationic conductivity is a necessary characteristic of the nerve conduit ensuring effective regeneration of the peripheral nerves. We performed a functional assessment of the regeneration of rat sciatic nerve using a nerve conduit based on an ion-exchange membrane. A sciatic nerve defect was experimentally simulated in Wistar rats with further implantation of the LF-4SK membrane. On days 60 and 90 after surgery, the sciatic functional index and the ratio of the shin girth of the operated limb to the intact limb were calculated; on day 90, an electrophysiological assessment of nerve recovery was carried out. The results of the study showed that the conduit based on the LF-4SK membrane optimizes the functional recovery of the sciatic nerve defect.

Background: Current studies show that hollow conduits in combination with various synthetic and biological fillers significantly accelerate functional recovery of peripheral nerves. One of such fillers can be a hydrogel based on the extracellular matrix of the dermis, which contains surface ligands capable of providing topographic and biological signals for nerve regeneration.Objective: To evaluate the effectiveness of rat sciatic nerve regeneration using a collagen conduit filled with dermal hydrogel in an in vivo experiment.Materials and methods: We evaluated the effectiveness of the NeuraGen® collagen conduit filled with dermal hydrogel and compared it with that of an autograft and the NeuraGen® hollow collagen conduit in experimental treatment of rat sciatic nerve defects larger than 1 cm. Male Wistar rats underwent sciatic nerve resection. We calculated the Sciatic Functional Index (SFI) and ratio of the calf circumference in an operated limb to that in an intact limb on days 30, 60, and 90 after implantation. We performed electrophysiological tests and explanted samples for hematoxylin-eosin staining on day 90 of the experiment.Results: When assessing the SFI and electrophysiological parameters, the group of animals with autografts and the group with the NeuraGen® collagen conduits filled with dermal hydrogel demonstrated similar results. We observed muscle atrophy, low SFI scores, and low velocity and short duration of the action potential in the group with the hollow NeuraGen® collagen conduits. Histological analysis of explanted samples of the collagen conduits filled with dermal hydrogel demonstrated areas of glial proliferation and the absence of pronounced degeneration of nerve fibers throughout the implant compared with autografts, indicating functional regeneration of nerve fibers.Conclusions: Evaluation of the effectiveness of rat sciatic nerve regeneration showed that the NeuraGen® collagen conduit filled with dermal hydrogel provides functional and morphological integration with the nerve compared with an autograft. Our findings can be used for further development and improvement of nerve conduits.

Aim. To study the efficacy of dermal hydrogel application in the experimental treatment of superficial scarified wounds in rats. Materials and methods. The hydrogel was obtained from porcine dermis by alkaline hydrolysis. The DNA concentration was determined using the Nano Drop ND-1000 spectrophotometer. The study included 30 male Sphinx rats. Scarified wounds were created on the rat skin, then the rats were divided into two groups: group 1 – rats without treatment, or control group (n = 15), group 2 – rats with wound treatment with the dermal hydrogel for 5 days, or experimental group (n = 15). On day 3, 7, and 14 of the experiment, we explanted skin samples from the wound area and performed routine H&E staining. Results. On day 3 of the experiment, moderate inflammation, edema, and collagen fiber disorganization were revealed in the experimental group, and pronounced inflammation with purulent exudate was found in the control group. On day 7 of the experiment, inflammation and foci of stratified epithelium were detected in the control group. The histologic analysis of the skin samples from the experimental group showed pronounced plethora of the vessels, necrotic changes of the dermis, and edema. The total thickness of the epidermis and the thickness of its stratum corneum were greater than in the control group samples. On day 14, the differences between the groups were minimal and the epidermis was thickened in the experimental group animals. Conclusion. The study examined the effects of the dermal hydrogel on scarified wounds in rats. We found faster skin regeneration (by 1.5–2 days) in the experimental group compared to the controls. Besides, the rats of the experimental group were characterized by an increase in the number of fibroblasts in the dermis and thickened epidermis in the affected area.

Objective: To develop a biological implant that is an acellular dermal matrix (ADM), evaluate its use as a support material in tensionfree hernioplasty for ventral hernia, and compare it to that of the commercially available implant Permacol TM . Materials and methods: ADM was derived from the porcine dermis (Landrace breed) decellularized using detergents and enzymes. The quality of devitalization was assessed in vitro. We performed sublay hernioplasty in 4-month-old Landrace pigs using ADM (experimental group) and Permacol TM (control group). The specimens were explanted on day 120 of the experiment for histological and immunohistochemical examination. Results: All cellular elements were removed by the detergent-enzymatic treatment of the dermis; the native architecture of the dermis was slightly disrupted. The specimens of the commercially available chemically cross-linked biomaterial Permacol TM had better mechanical properties than ADM specimens; however, there were no significant differences in terms of cytotoxicity. The state of the tissues after the explantation (number of fibroblasts and endothelial cells) showed no differences in the result of using ADM and Permacol TM . In 120 days, the materials integrated into the tissues without the formation of adhesions or inflammation. Conclusions: Our findings show that ADM does not have cytotoxic properties, has adequate biomechanical parameters to effectively reinforce supporting soft tissues, does not cause an inflammatory response during implantation, and integrates fully into tissues. Our study demonstrates the effectiveness and utility of the developed ADM in surgical treatment of anterior abdominal wall defects.

The domestic pharmaceutical market still lacks reparative drugs, which determines research on their creation as an urgent theoretical and applied task. In this regard, the expediency of developing the composition and technology for obtaining a polycomponent gel with a predictable positive effect on wound healing processes based on dermal biopolymers and a complex of biologically active substances of corn columns with stigmas is substantiated. The complex of technological studies carried out made it possible to establish the optimal composition and technology for obtaining a polycomponent gel. At the next necessary stage of pharmaceutical development, it was necessary to solve the issues of assessing the quality of the proposed composition of the polycomponent gel. The purpose of this study was to determine the criteria and methods for monitoring the quality indicators of a multicomponent reparative gel. The object of the study was experimental samples of a multicomponent gel obtained by introducing a thick extract of corn columns with stigmas into a collagen base. The quality of the polycomponent gel was assessed in accordance with the requirements of GPM.1.4.1.0008.15 "Ointments" of the State Pharmacopoeia IV edition according to the following criteria: "Description", pH, "Microbiological purity", authenticity and quantitative content of active substances. The indicator "Description" was evaluated organoleptically. The determination of the pH of the gel was carried out potentiometrically using a pH meter (Mettler Toledo, USA) according to GPM.1.2.1.0004.15 "Ionometry" directly in the gel sample. Microbiological purity was studied by the agar plate method in accordance with GPM.1.2.4.0002.15. The presence and quantitative determination of flavonoids in the developed gel was determined spectrophotometrically on a UV-1800 SHIMADZU spectrophotometer, Japan. As a result of the studies carried out, the criteria for the quality of a multicomponent gel of reparative action were studied and proposed. According to the "Description" indicator, the polycomponent gel is a homogeneous mass of light brown color with a pleasant fruity odor without impurities. It has been established that the polycomponent gel is characterized by a slightly alkaline pH value, which creates optimal conditions for the healing phase of the wound process. It is shown that the use of the method of differential spectrophotometry makes it possible to carry out a statistically significant qualitative and quantitative assessment of the content of flavonoids in the composition of a polycomponent gel.

We performed a comprehensive assessment of the acellular dermal matrix obtained during the detergent-enzymatic treatment of the porcine dermis. Acellular dermal matrix was used for the experimental treatment of a hernial defect in a pig using the sublay method. Sixty days after the surgery, biopsy specimens were obtained from the area of hernia repair. The acellular dermal matrix can be easily modeled depending on the size and shape of the defect during surgical procedures, can eliminate the defect of the anterior abdominal wall, and is resistant to cutting by the suture material. Histological examination demonstrated replacement of the acellular dermal matrix with newly formed connective tissue.

The aim of the study was to select the optimal method for creating surgical porcine dermis-based biomaterials and to assess their biological safety.Materials and Methods.To create xenodermal biomaterials, the native skin of a 4-month-old Landrace pig was used.The porcine dermis was processed with saline (protocol No.1), peroxide-alkaline (protocol No.2), and alkaline (protocol No.3) solutions.The obtained samples were stained with hematoxylin-eosin and a DAPI fluorescent dye.Quantitative DNA analysis and assessment of cytotoxicity by the LIVE/DEAD assay were also performed.Samples were implanted/injected subcutaneously to 6-month-old male Wistar rats (n=30) weighing 260±20 g and explanted on day 14 of the experiment.Histological sections were stained with hematoxylin-eosin.Computer morphometry was performed using GraphPad Prism v. 6.04.Results.Samples of surgical materials obtained according to the three protocols had different physical characteristics: dermis treated according to protocol No.1 was dense and white in color after processing; samples processed by protocol No.2 were transparent and dense, and samples treated according to protocol No.3 had transparent gel-like structures.Histological analysis has shown oxyphilicity and extracellular matrix structure loss in all samples, and DAPI staining has revealed the destruction of cell nuclei.Nevertheless, DNA amount in the samples processed according to protocol No.1 did not meet the established quality criterion for decellularization (50 ng/mg dry weight).Further cytotoxicity assessment in vitro and in vivo was carried out only for samples fabricated according to protocols No.2 and No.3.According to the LIVE/DEAD analysis, both samples were not cytotoxic.On day 14 after the subcutaneous sample implantation, no signs of suppuration and immune rejection were found in the animals. Conclusion.To obtain surgical materials in the form of bioplastic coatings, it is recommended to use alkaline-peroxide treatment of the dermis, while hydrogel coatings are produced by alkaline hydrolysis.

Nowadays urolithiasis (nephrolithiasis) is a common disease, which treatment is a serious task of health care ser- vices not only in Russia, but throughout the world. At the same time, stones of a calcium-oxalate nature are the most common stones in patients with this pathology – in about 70-80% of cases. It is also worth noting that this disease not only has rather painful manifestations, and its treatment requires large financial costs, but also has a complex multi- factorial multistage pathogenesis, understanding the mechanisms of which can provide a key to the development of the most successful therapy. Pathogenesis itself consists of several stages, such as nucleation with the formation of a crystallization center, crystal growth, aggregation and their attachment to the surface of epithelial cells. It is known that the human body contains various substances that affect the processes of stone formation. Thus, stone formation promoters facilitate their crystallization, and inhibitors prevent it. There is a delicate balance between promoters and inhibitors, and their imbalance is often a decisive factor in pathogenesis. By their chemical nature, inhibitors can be both inorganic and organic (proteins, glycosaminoglycans) substances. The latter are especially attracting attention, since at various concentrations they can act as both inhibitors and promoters of stone formation. To fully understand the mechanisms of calcium oxalate stone formation, this review analyzes current data on inhibitors of recurrent nephrolithiasis and their role in the pathophysiology of the process of renal stone formation.

Objective: To determine the optimal technological modes for the preparation of platelet-rich plasma (PRP) using standard laboratory equipment.Material and methods: Blood for the research was taken from 25 healthy volunteers. Its centrifugation was performed on a standard CM-6M laboratory centrifuge using various modes and two types of vacuum tubes with lithium heparin containing separation gel and without it. The number of platelets and leukocytes was calculated in the upper, lower and middle layers of the obtained plasma sample.Results: Plasma samples obtained during centrifugation modes from 415 to 1660 g for 10 minutes using test tubes that do not contain separation gel are optimal in terms of the number of platelets. Plasma intake from the lower layer of the obtained sample after centrifugation is always accompanied by the inclusion of leukocytes in its composition, which can lead to undesirable tissue reactions when it is used.Conclusion: To obtain PRP, it is possible to use standard laboratory equipment in the centrifugation mode from 415 to 1660 g for 10 minutes using test tubes that do not contain separation gel. Plasma sampling for clinical use should be carried out from the middle layer of the obtained sample.

Abstract: Effective treatment of wound processes is an urgent task for medical practice. Among the local medications used for these pathologies, hydrogel wound dressings based on biopolymers have become increasingly popular in recent years. Natural gelling agents, along with a positive effect on the healing process, are able to successfully perform the functions of a carrier of other biologically active components. In particular, it seems relevant to introduce into the composition of such hydrogels the extraction complex of maize columns with stigmas, enriched with substances with antioxidant, immunotropic and hemostatic properties. In this regard, it seems expedient to develop a technology for obtaining an extraction complex from maize columns with stigmas in the form of a thick extract. The object of the study was commercial samples of corn columns with stigmas that meet the requirements of regulatory documentation. Determination of extractive substances of plant raw materials, quantitative content of flavonoids, dry residue of extracts, weight loss during drying of a thick extract was carried out by pharmacopoeial methods. Spectrophotometric studies were carried out on a Shimadzu UV-1800 spectrophotometer. As an extractant for extracting the phytocomplex, 70% ethyl alcohol was used. Extraction of raw materials was carried out by vacuum filtration extraction. The alcohol extracts were concentrated using an IR-1M2 rotary evaporator. Grinding of corn columns with stigmas was carried out by crushing with simultaneous attrition using a laboratory two-roll grinder, which ensured the achievement of the raw material characteristics necessary for vacuum filtration extraction. The results of vacuum filtration extraction of corn columns with stigmas showed that the use of this method makes it possible to achieve the transfer of 90,4% of the total amount of biologically active substances and 83,7% of flavonoids into the first three plums, a further increase in the number of plums is inappropriate. In order to remove accompanying substances, the combined extract was kept at a temperature not exceeding 10°C for 2 days, and the precipitate that formed was filtered off. Determination of the content of "dry residue" and flavonoids in the purified extract showed that, as a result of purification, mainly associated substances were in the sediment, while the active substances remained in a dissolved state in the composition of the extract. In order to obtain a thick extract, the extract was concentrated using a rotary evaporator at a temperature of 50-60°C to the required consistency and a residual moisture content of no more than 25%.

Acellular dermal matrices (ADMs) are gaining popularity as surgical materials for operations on the pelvic organs, as well as in burn therapy and plastic surgery. Evaluation of the biocompatibility of surgical materials is an important and necessary step in the development of new ADMs.The aim of the study was to compare the results of subcutaneous implantation of ADM and native porcine skin in rats.Materials and methods. To obtain ADMs, detergent – enzymatic decellularization was used. On days 7, 14, 21, and 60 after the implantation of ADMs (the experimental group) and native porcine skin (the control group), the animals were removed from the experiment. The histologic sections were stained with hematoxylin – eosin and Masson’s trichrome stain, then an immunohistochemical reaction with antibodies to CD3 and CD68 was performed. Computer morphometry was carried out using the ImageJ software.Results. On day 7 after the implantation, moderate sterile inflammation in the experimental group and pronounced sterile inflammation with eosinophil infiltration in the control group were observed. On day 14 of the experiment, the samples from the experimental group were characterized by a relatively low content of macrophages and T-lymphocytes with insignificant edema and no signs of ADM biodegradation. The control group showed pronounced inflammation, a large number of infiltrating macrophages and T lymphocytes, as well as fragmentation of collagen fibers. On day 21 of the experiment, a thin capsule was formed around ADM, there was a small number of infiltrating T lymphocytes and macrophages, the collagen fibers of the implant were intact. In the samples of the control group, there was pronounced inflammation with the presence of a significant number of lymphocytes and macrophages, as well as fragmentation and vascularization of the implant. On day 60 of the experiment, no inflammatory response was observed around ADM, biodegradation was minimal, and a dense fibrous capsule was formed around the fragment of the native porcine skin.Conclusion. The experimental ADM has low immunogenicity and a low degree of biodegradation, which makes it possible to use it for further research to create efficient surgical material that is safe for use in clinical practice.

Разработка лекарственных препаратов для лечения ран представляет собой актуальную теоретическую и прикладную задачу, в связи с чем обоснованна целесообразность разработки состава и технологии поликомпонентного репаративного действия на основе биополимеров дермы и комплекса биологически активных веществ кукурузы столбиков с рыльцами. Проведенные исследования позволили предложить оптимальный состав и технологию получения поликомпонентного геля. Целью настоящего исследования являлось определение критериев и методик контроля показателей качества поликомпонентного геля репаративного действия. В качестве критериев качества поликомпонентного геля изучены показатели «описание», рН, «микробиологическая чистота», «подлинность» и «количественное содержание суммы флавоноидов в пересчете на лютеолин-7-гликозид». The development of drugs for the treatment of wounds is an urgent theoretical and applied problem, in connection with which the expediency of developing the composition and technology of a multicomponent reparative action based on dermal biopolymers and a complex of biologically active substances of corn silk is substantiated. The studies carried out made it possible to propose the optimal composition and technology for obtaining a polycomponent gel. The purpose of this study was to determine the criteria and methods for monitoring the quality indicators of a multicomponent reparative gel. As criteria for the quality of a multicomponent gel, the indicators "description", pH, "microbiological purity", "authenticity" and "quantitative content of the sum of flavonoids in terms of luteolin-7-glycoside" were studied.

Electrodialysis (ED) is an attractive method of tartrate stabilization of wine due to its rapidity and reagentlessness. At the same time, fouling of ion-exchange membranes by the components of wine materials is still an unsolved problem. The effect of ethanol, polyphenols (mainly anthocyanins and proanthocyanidins) and saccharides (fructose) on the fouling of aliphatic ion-exchange membranes CJMA-6 and CJMC-5 (manufactured by Hefei Chemjoy Polymer Materials Co. Ltd., Hefei, China) was analyzed using model solutions. It was shown that the mechanism and consequences of fouling are different in the absence of an electric field and during electrodialysis. In particular, a layer of colloidal particles is deposited on the surface of the CJMA-6 anion-exchange membrane in underlimiting current modes. Its thickness increases with increasing current density, apparently due to the implementation of a trap mechanism involving tartaric acid anions, as well as protons, which are products of water splitting and “acid dissociation”. A successful attempt was made to clean CJMA-6 in operando by pumping a water-alcohol solution of KCl through the desalination compartment and changing electric field direction. It has been established that such a cleaning process suppresses the subsequent biofouling of ion-exchange membranes. In addition, selective recovery of polyphenols with high antioxidant activity is possible.

Background. With the introduction of synthetic mesh implants into clinical practice, the recurrence rate of postoperative ventral hernias was signifi cantly reduced. The extensive use of synthetic implants led to the development of specifi c complications. The development of biological implants, based on extensively purifi ed decellularized collagen matrix of xenogeneic origin is highly relevant due to the fact that, unlike synthetic analogues, they have a biological origin and biodegrade in a natural way, gradually being replaced with newly formed connective tissue. The use of bioprostheses reduces the risk of complications.Objectives. To conduct a comparative evaluation of the biomechanical characteristics of acellular dermal matrix, obtained by detergent-enzymatic decellularization, and commercially distributed Permacol™ matrix.Methods. Acellular dermal matrix (ADM) was created by using samples of native skin of pig of Landras breed aged 4 months. The dermis was processed by means of detergent-enzymatic method. In order to evaluate and compare the mechanical properties of acellular dermal matrix, the biological samples were divided into 2 groups of 15 samples each. The fi rst group included acellular dermal matrix samples, the second group — native samples of pigs unprocessed dermis. The control group consisted of samples of PermacolTM Surgical Implant, xenotransplant for hernioplasty approved for use in the Russian Federation (Covidien, France). All samples were tested wet using universal testing instrument Instron 1122. MedCalc Statistical Software (Belgium) was used for statistical processing of the study results.Results. In the present study, pig dermis was processed using a detergent-enzymatic method to produce ADM. Routine histological examination confi rmed the removal of all cellular elements, and at the same time it was proven that the native structure of the dermis remained intact during its processing. The mechanical characteristics of xenogenic ADM were further determined. Its tensile strength was 9.1 ± 0.6 MPa (910 N/cm2 ), elongation to break was 21.1 ± 2.3%, and elastic modulus was 50.0 ± 1.6 MPa. These characteristics largely corresponded to the strength characteristics of native pig dermis and far exceeded the necessary physiological parameters. PermacolTM control was tested in two directions (longitudinal and transverse). In the longitudinal direction, the sample had higher mechanical characteristics: strength — 12.0 ± 1.7 MPa, elongation to break — 29.7 ± 2.4%, stiffness modulus — 47.2 ± 6.5 MPa. In the transverse direction, all indicators were 1.5–2 times lower.Conclusion. The developed xenogeneic biological implant in the form of ADM demonstrates rather good characteristics of plasticity, tensile strength and elasticity, to be used as a biological endoprosthesis for plasty of hernia defects of the abdominal wall of any size and shape.

We carry out a comparative assessment of the degree of nuclear material disintegration and elimination in the samples of decellularized porcine dermis after using chemical, detergent and enzymatic decellularization methods. Decellularized dermis materials are promising materials as wound dressings. The chemical method (Protocol No. 1) was performed using NaOH and H2 O2 solutions; the detergent method (Protocol No. 2) involved the solutions of Triton X-100 and sodium deoxycholate in combination with Na2 -EDTA; the enzymatic method (Protocol No. 3) was based on the solutions of trypsin Versene and porcine pan creatic DNase. Subsequently, we analyzed the DNA amount in decellularized and native dermis (control group) samples. The results of this analysis showed positive results in all three protocols. It was found that the detergent method have advantages over other methods of producing decellularized dermis matrices.

The broad possibilities of electrochemical impedance spectroscopy for assessing the capacitance of interphase boundaries; the resistance and thickness of the foulant layer were shown by the example of AMX-Sb membrane contacted with red wine from one side and 0.02 M sodium chloride solution from the other side. This enabled us to determine to what extent foulants affect the electrical resistance of ion-exchange membranes, the ohmic resistance and the thickness of diffusion layers, the intensity of water splitting, and the electroconvection in under- and over-limiting current modes. It was established that short-term (10 h) contact of the AMX-Sb membrane with wine reduces the water-splitting due to the screening of fixed groups on the membrane surface by wine components. On the contrary, biofouling, which develops upon a longer membrane operation, enhances water splitting, due to the formation of a bipolar structure on the AMX-Sb surface. This bipolar structure is composed of a positively charged surface of anion-exchange membrane and negatively charged outer membranes of microorganisms. Using optical microscopy and microbiological analysis, it was found that more intense biofouling is observed on the AMX-Sb surface, that has not been in contacted with wine.