Recent advancements in systemic drug delivery emphasize the use of innovative technologies, such as pH-sensitive drug carriers, to achieve precise and efficient targeting within the body. These approaches hold significant promise for controlling drug delivery and guiding drugs to specific targets. This study investigates the fabrication of core-shell particles utilizing mesoporous vaterite particles coated with pH-sensitive alginate and cellulose. The research reveals that the formed coatings influence alterations in particle morphology and zeta potential, resulting in consistent pH-dependent release profiles. Furthermore, the negative potential reduces the uptake efficiency of the resulting particles into Raw264.7 immune cells, demonstrating the potential for prolonged circulation time and increased bioavailability of the encapsulated substances. These findings underscore the potential efficacy of such systems for targeted drug delivery and their potential impact within the context of pH-sensitive drug delivery systems.

Wound care remains a significant healthcare challenge, with associated costs continuing to rise over the past decade. The advancement of innovative wound dressings that actively facilitate healing has emerged as a pivotal research focus. This study introduces a novel design for functional microstructured wound dressings, utilising microencapsulation technology to enhance wound healing. This methodology allows for precise tuning of the chemical microenvironment within the wound bed. An original solid-powder encapsulation methodology is employed, facilitating the sustained and controlled release of bioactive compounds. The effects of sustained release are demonstrated by modulating oxidative stress through the administration of antioxidants and hydrogen peroxide. Sustained release of active compounds within the wound is shown to modulate angiogenesis, exert antiseptic and anti-inflammatory effects, and promote scar-free tissue formation. The fundamental role of ultralow doses and sustained-release of hydrogen peroxide and antioxidants in tissue regeneration was simultaneously investigated. The observed bioeffects of microchamber-based wound dressings highlight the potential of advanced materials and encapsulation strategies to actively regulate the wound milieu and provide sustained, tailored therapeutic effects by a slight shift of the chemical profile. The proposed technique establishes a foundation for the development of wound healing systems characterised by hierarchical multifunctionality. Our approach presents a variety of unique features and potential applications, including anisotropic manipulations, site specific and on-demand release, integration with cell therapy, and more. Further research is warranted to explore the clinical translation and broader applications of this technology for wound management.

In vitro and in vivo effects of mesoporous silica nanoparticles (MSN) on the functional activity of platelets were studied in experiments on white rats. MSN particles, neither uncoated nor coated with calcium alginate, induced spontaneous platelet aggregation when added to platelet-rich plasma, but significantly enhanced ADP-induced platelet aggregation. Subcutaneous administration of uncoated and calcium alginate-coated MSN resulted in increased maximum size and rate of platelet aggregate formation 1 day post-injection. In contrast, cellulose-coated MSN had no significant effect on platelet function in vitro or in vivo, suggesting their potential as carriers for targeted drug delivery.

Введение. Свободнорадикальные процессы являются неотъемлемой частью заживления ран, с одной стороны оказывая альтерирующее действие на собственные ткани, и с другой являясь важными регуляторами репаративных процессов. Использование адресной доставки прооксидантов и антиоксидантов в лечении ран открывает новые перспективы для улучшения исходов регенерации. В этой связи целью настоящего исследования явилось изучение влияния микрокамерных полилактидных раневых покрытий, обеспечивающих адресную доставку про- и антиоксидантных компонентов, на состояние ферментативного и неферментативного звеньев антиоксидантной защиты у крыс с послойным эксцизионным дефектом кожи. Методика. Исследование проведено на 81 белой крысе, разделенных на пять групп: контрольную (n=9), сравнительную (n=18), три опытные (по n=18). У животных сравнительной и опытных групп оперативным путем создавалась модель кожной раны размером 10×10 мм. Животным опытной группы № 1 дефект закрывался полилактидным микрокамерным раневым покрытием без активных компонентов. Крысам опытных групп №2 и 3 накладывалось аналогичное покрытие, микрокамеры которого были загружены таниновой кислотой и перкарбонатом натрия соответственно. Оценивались активность супероксиддисмутазы и каталазы, а так же концентрация тиоловых групп в сыворотке крови. Результаты. Повреждение кожи вызывает изменения ферментативного и неферментативного звеньев актиоксидантной защиты, что проявляется увеличением активности супероксиддисмутазы и каталазы, а также снижением тиолового статуса у крыс группы сравнения. Применение микрокамерного раневого покрытия, загруженного таниновой кислотой, частично восстанавливает концентрацию тиоловых групп и активность супероксиддисмутазы и каталазы в сыворотке крови. Применение микрокамерного раневого покрытия с перкарбонатом натрия способствует частичному снижению активности супероксиддисмутазы, относительно группы сравнения, а так же повышению концентрации тиоловых групп в сыворотке крови на поздних этапах репаративного процесса, но при этом практически не оказывает влияние на активность каталазы. Выводы: Таким образом, загрузка про- и антиоксидантных компонентов в микрокамерное полилактидное покрытие позволяет корректировать изменения тиолового статуса, активности супероксиддисмутазы и каталазы у крыс полнослойным дефектом кожи. Introduction. Free-radical processes are an integral part of wound healing. On one hand, they have an altering effect on tissues, and on the other hand, they are important regulators of reparative processes. The targeted delivery of pro- and antioxidants in wound treatment opens new prospects for improving regeneration outcomes. Thus, the aim of this study was to investigate the effect of microchamber polylactide wound dressings that provide targeted delivery of pro- and antioxidant components on enzymatic and non-enzymatic elements of antioxidant protection in rats with full-thickness skin surgical wounds. Methods. The study was carried out on 81 male white rats divided into five groups: normal, control group (n=9), comparison group with untreated wound (n=18), and three experimental, treated groups (n=18 each). In animals of the comparison and experimental groups, a skin wound 10×10 mm was surgically created. In experimental group 1, a polylactide microchamber wound dressing without active components was applied to the formed skin defect. In experimental groups 2 and 3, a similar dressing was applied, in which the microchambers were loaded with tannic acid and sodium percarbonate, respectively. The activities of superoxide dismutase and catalase and the serum concentration of total thiol groups were assessed. Results. In rats of the comparison group, skin damage caused changes in the enzymatic and non-enzymatic components of antioxidant protection that are manifested by an increase in the activity of superoxide dismutase and catalase and a decrease in thiol status. The use of a microchamber wound dressing saturated with tannic acid partially restored the concentration of thiol groups and the activity of superoxide dismutase and catalase in the blood serum. The use of microchamber wound dressing with sodium percarbonate produced a partial decrease in the activity of superoxide dismutase compared to the comparison group and an increase in thiol groups at the later stages of the reparative process, but had virtually no effect on the activity of catalase. Conclusion: Thus, loading pro- and antioxidant components into a microchamber polylactide coating makes it possible to correct changes in thiol status and superoxide dismutase and catalase activities in a full-thickness skin wound.

The development of advanced methods for the synthesis of nano- and microparticles for biomedical applications is of considerable interest. A method for synthesizing submicron silver-shelled calcium carbonate particles using a microfluidic chip designed to control the particle formation is proposed. Precise control of reaction parameters enables controlled formation of silver shell and calcium carbonate particles. The distribution of pores in the hybrid particles was analyzed using small-angle X-ray scattering, which gained insight into the complex structure of the pores. The results provide information on the particle morphology and may facilitate the development of new calcium carbonate-based materials for various applications.

The development of advanced methods for the synthesis of nano- and microparticles for biomedical applications is of considerable interest. A method for the synthesis of submicron silver-shelled calcium carbonate particles using a microfluidic chip designed to provide control over particle formation is proposed. Precise control of reaction parameters enables the formation of silver shell and calcium carbonate particles in a controlled manner. The distribution of pores in the hybrid particles was analyzed using small-angle X-ray scattering, which provided insight into the complex structure of the pores. The results provide information on particle morphology and may facilitate the development of new calcium carbonate-based materials for various applications.

Хронический пародонтит представляет собой мультифакторное заболевание со сложным этиопатогенезом, включающим воспалительный ответ, эндотелиальную дисфункцию и костную резорбцию как реакции на негативное воздействие пародонтопатогенной флоры. Таргетная доставка активных компонентов, включая антибактериальные, их пролонгированное высвобождение и направленное действие на ключевые звенья патогенеза открывают новые перспективы повышения качества пародонтального лечения. Использование технологий микрокапсулирования позволяет функционально модифицировать стоматологические гели за счёт возможностей регулирования высвобождения активных компонентов. Цель. Оценить влияние сочетанной загрузки метронидазола и таниновой кислоты в альгинатные микрокапсулы на системные проявления эндотелиальной дисфункции, воспалительный ответ и костную резорбцию при экспериментальном пародонтите у крыс. Материал и методы. Исследование проведено на 50 крысах-самцах. Группа контроля – 10 интактных крыс. Группа сравнения – 10 животных с экспериментальным пародонтитом (ЭП), опытные группы №1, №2 и №3 включали по 10 крыс с ЭП, которым проводились аппликации геля, содержащего микрокапсулы, загруженные таниновой кислотой (ТК), метронидазолом (МТ) и их сочетанием (ТК+МТ), соответственно. Общая продолжительность эксперимента составляла 5 недель, затем в сыворотке крови оценивали концентрацию маркёров воспалительного ответа (моноцитарного хемоаттрактантного белка 1 и С-реактивного белка), альтерации эндотелия (васкулоэндотелиального фактора роста, sE-селектина, синдекана-1), а также деструкции костной ткани (С-терминальных белковых фрагментов коллагена I типа). Результаты. Развитие ЭП у крыс сопровождается увеличением концентрации маркёров системного воспалительного ответа, альтерации эндотелия, а также резорбции костной ткани. Применение геля, микрокапсулы которого были загружены одним из активных компонентов (МТ или ТК), снижает уровень маркёров системного воспалительного ответа, альтерации и дисфункции эндотелия и резорбции костной ткани у крыс с ЭП. Комбинация в составе микрокапсул МТ и ТК, у крыс с ЭП эффективнее снижает повышенные концентрации в крови С-реактивного белка, моноцитарного хемоаттрактантного белка-1, фактора роста эндотелия сосудов и фрагментов коллагена I типа по сравнению с аналогами, загруженными только одним из компонентов. Заключение. Сочетание антибактериальных и противовоспалительных компонентов позволяет добиться наиболее выраженной коррекции ключевых звеньев патогенеза хронического пародонтита, включая воспалительный ответ и его системные проявления, эндотелиальную дисфункцию, а также резорбцию костной ткани. Chronic periodontitis is a multifactorial disease with a complex etiopathogenesis, including an inflammatory response, endothelial dysfunction and bone resorption as a reaction to the negative impact of periodontal pathogenic flora. Targeted delivery of active components, including antibacterial ones, their prolonged release and directed action on the key links in pathogenesis, open up new prospects for improving the periodontal treatment quality. The use of microencapsulation technologies allows to functionally modify dental gels due to possibility to regulate the release of active components. The aim of this study was to evaluate the effect of combined loading of metronidazole and tannic acid into alginate microcapsules on systemic manifestations of the inflammatory response, endothelial dysfunction and bone resorption in periodontitis in experimental rats. Material and methods. The study was carried out on 50 male rats. Control group – 10 intact rats. Comparison group – 10 animals with experimental periodontitis (EP), experimental groups No. 1, No. 2 and No. 3 each included 10 rats with EP, which received applications of a gel containing microcapsules loaded with tannic acid (TA), metronidazole (MT) and their combination (TA+MT), respectively. The total duration of the experiment was 5 weeks, then the concentration of markers of the inflammatory response (monocyte chemoattractant protein 1 and C-reactive protein,), endothelial alteration (vasculoendothelial growth factor, sE-selectin, syndecan-1), and bone tissue destruction (C-terminal protein fragments of type I collagen) was assessed in the blood serum. Results. The development of EP in rats is accompanied by an increase in the concentration of markers of the systemic inflammatory response, alteration of the endothelium, as well as bone tissue resorption. The use of a gel, microcapsules of which were loaded with TA or MT separately, reduces the level of markers of the systemic inflammatory response, alteration and dysfunction of the endothelium and bone resorption in rats with EP. The combination of TA and MT in microcapsules in rats with EP effectively reduces elevated blood concentrations of C-reactive protein, monocyte chemotactic protein-1, vascular endothelial growth factor and type I collagen fragments compared to analogues loaded with only one of the components. Conclusion. The combination of antibacterial and anti-inflammatory components allows achieving the most pronounced correction of key links in the pathogenesis of chronic periodontitis, including the inflammatory response and its systemic manifestations, endothelial dysfunction, and bone tissue resorption.

The development of advanced methods for the synthesis of nano- and microparticles in the field of biomedicine is of high interest due to a range of reasons. The current synthesis methods may have limitations in terms of efficiency, scalability, and uniformity of the particles. Here, we investigate the synthesis of submicron calcium carbonate using a microfluidic chip with a T-shaped oil supply for droplet-based synthesis to facilitate control over the formation of submicron calcium carbonate particles. The design of the chip allowed for the precise manipulation of reaction parameters, resulting in improved porosity while maintaining an efficient synthesis rate. The pore size distribution within calcium carbonate particles was estimated via small-angle X-ray scattering. This study showed that the high porosity and reduced size of the particles facilitated the higher loading of a model peptide: 16 vs. 9 mass.% for the particles synthesized in a microfluidic device and in bulk, correspondingly. The biosafety of the developed particles in the concentration range of 0.08–0.8 mg per plate was established by the results of the cytotoxicity study using mouse fibroblasts. This innovative approach of microfluidically assisted synthesis provides a promising avenue for future research in the field of particle synthesis and drug delivery systems.

Objective: To evaluate the effect of metronidazole loaded into silver impregnated alginate microcapsules on the structural and functional disorders of the dental support apparatus in periodontitis. Material and methods. The studies were carried out on 30 white male rats randomly divided into two groups. Comparison group — 15 animals with an experimental model of periodontitis, which underwent applications of a gel containing microcapsules without additional loading with active substances. The experimental group included 15 animals with periodontitis, which were subjected to applications of gel with microcapsules containing metronidazole on inflamed gums. To assess the morphological changes in the supporting apparatus of the tooth, the mandible was taken with subsequent histological examination. Results. Results. Application of a gel containing microcapsules with silver nanoparticles loaded with metronidazole on the gums of animals with periodontitis leads to partial reduction of structural disorders. Thus, local disorganization of the fibers of the circular ligament of the tooth in the experimental group was observed only 5 cases, signs of limited bone loss — in 2 cases out of 15. In the comparison group, all 15 animals showed bone resorption and in 13 of 15 cases there was diffuse fiber alteration throughout the circumferential ligament of the tooth. Conclusion. The inclusion of alginate microcapsules with silver nanoparticles metronidazole leads to a significant decrease in destructive processes occurring in the near-tooth tissues during periodontitis.

The search for novel therapeutic strategies to treat fungal diseases is of special importance nowadays given the emerging threat of drug resistance. Various particulate delivery systems are extensively being developing to enhance bioavailability, site-specific penetration, and therapeutic efficacy of antimycotics. Recently, we have designed a novel topical formulation for griseofulvin (Gf) drug, which is currently commercially available in oral dosage forms due to its limited skin permeation. The proposed formulation is based on vaterite carriers that enabled effective incorporation and ultrasonically assisted delivery of Gf to hair follicles improving its dermal bioavailability. Here, we evaluated the effect of ultrasound on the viability of murine fibroblasts coincubated with either Gf-loaded carriers or a free form of Gf and investigated the influence of both forms on different subpopulations of murine blood cells. The study revealed no sufficient cyto- and hemotoxicity of the carriers, even at the highest investigated concentrations. We also conducted a series of in vivo experiments to assess their multi-dose dermal toxicity and antifungal efficiency. Visual and histological examinations of the skin in healthy rabbits showed no obvious adverse effects after US-assisted application of the Gf-loaded carriers. At the same time, investigation of therapeutic efficiency for the designed formulation in comparison with free Gf and isoconazole drugs in a guinea pig model of trichophytosis revealed that the vaterite-based form of Gf provided the most rapid and effective cure of infected animals together with the reduction in therapeutic procedure number. These findings pave the way to improving antifungal therapy of superficial mycoses and justifying further preclinical studies.

Transcutaneous immunization receives much attention due to the recognition of a complex network of immunoregulatory cells in various layers of the skin. The elaboration of non-invasive needle-free approaches towards antigen delivery holds especially great potential here while searching for a hygienically optimal vaccination strategy. Here, we report on a novel protocol for transfollicular immunization aiming at delivery of an inactivated influenza vaccine to perifollicular antigen presenting cells without disrupting the stratum corneum integrity. Porous calcium carbonate (vaterite) submicron carriers and sonophoresis were utilized for this purpose. Transportation of the vaccine-loaded particles into hair follicles of mice was assessed in vivo via optical coherence tomography monitoring. The effectiveness of the designed immunization protocol was further demonstrated in an animal model by means of micro-neutralization and enzyme-linked immunosorbent assays. The titers of secreted virus-specific IgGs were compared to those obtained in response to intramuscular immunization using conventional influenza vaccine formulation demonstrating no statistically significant differences in antibody levels between the groups. The findings of our pilot study render the intra-follicular delivery of the inactivated influenza vaccine by means of vaterite carriers a promising alternative to invasive immunization.

The paradigm of drug delivery via particulate formulations is one of the leading ideas that enable overcoming limitations of traditional chemotherapeutic agents. The trend toward more complex multifunctional drug carriers is well-traced in the literature. Nowadays, the prospectiveness of stimuli-responsive systems capable of controlled cargo release in the lesion nidus is widely accepted. Both endogenous and exogenous stimuli are employed for this purpose; however, endogenous pH is the most common trigger. Unfortunately, scientists encounter multiple challenges on the way to the implementation of this idea related to the vehicles' accumulation in off-target tissues, their immunogenicity, the complexity of drug delivery to intracellular targets, and finally, the difficulties in the fabrication of carriers matching all imposed requirements. Here, we discuss fundamental strategies for pH-responsive drug delivery, as well as limitations related to such carriers' application, and reveal the main problems, weaknesses, and reasons for poor clinical results. Moreover, we attempted to formulate the profiles of an "ideal" drug carrier in the frame of different strategies drawing on the example of metal-comprising materials and considered recently published studies through the lens of these profiles. We believe that this approach will facilitate the formulation of the main challenges facing researchers and the identification of the most promising trends in technology development.

dressing. Recent technological designs provide opportunities of modernization of preveosly used polylactide homogeneous structure by changing the microarchitectonics and by including in the structure of wound dressing microchamber arrays for active substances download. But changing the structure of the polymer can caused side effects or reactions in vivo. The aim of this study was to evaluate the biocompatibility of a polylactide microchamber wound dressing in the area of an experimental skin wound using tissue morphological analysis. The study was carried out on male rats divided into three groups: the control group (10 intact animals), the comparison group (30 rats, subjected to modeling of an acute excisional skin wound), the experimental group (30 rats, subjected to modeling of an acute excisional skin wound, which was closed with a polylactide microchamber wound dressing). After the formation of an experimental excisional skin wound, characteristic histomorphological changes in tissues associated with the inflammatory process and remodeling was noted as a result of the research. The use of polylactide wound dressing does not cause additional alterative effect on tissues, and promote wound healing. Results of present study allow to conclude that that the microchamber wound dressing made of polylactide is completely biocompatible.

Currently, the development of drug delivery systems is an important trend in modern biomedicine. During the last five years, a tendency is observed to complicate the developed carriers with the production of complex multicomponent carriers in order to improve the targeting and selectivity of their action. For this purpose, various properties characteristic for particular sites of a body are used, thus making it possible to specify the action of the carriers. One of the used factors is the medium pH, which is strictly regulated by an organism and is constant in a particular site of it. In this work, we develop an approach to the formation of complex core–shell particles based on mesoporous calcium carbonate particles and AMS-6 silica particles. The loading capacity of the obtained complex particles with respect to TRITC–BSA model dye and the kinetics of its release from them are studied. The carriers obtained in the work are promising to be used as drug carriers with pH-dependent release kinetics of encapsulated drugs.

Введение. Широкая распространенность открытых повреждений кожи вынуждает искать новые подходы к лечению кожных ран. Перспективным, с точки зрения эффективности и экономической целесообразности, является применение полилактидного микрокамерного раневого покрытия, загруженного таниновой кислотой. Динамика заживления кожных ран тесно коррелирует с изменениями в системе микроциркуляции. Цель исследования – оценка состояния микроциркуляции при применении полилактидного микрокамерного раневого покрытия, загруженного таниновой кислотой. Методика. Исследование проведено на 55 белых крысах самцах, разделенных на 4 группы: интактные животные (n=10), группа сравнения (n=15), группа «плацебо» (n=15) и опытная группа (n=15). У животных группы сравнения оперативным путем моделировали острую эксцизионную кожную рану размером 10×10 мм, которая не подвергалась в дальнейшем лечению. Животным группы «плацебо» на рану однократно укладывалось полилактидное микрокамерное раневое покрытие без активных компонентов, крысам опытной группы на сформированный кожный дефект однократно укладывалось полилактидное раневое покрытие идентичного размера, микрокамеры которого были загружены таниновой кислотой. Состояние микроциркуляции во всех группах оценивалось методом лазерной доплеровской флоуметрии. Оценивался средний показатель перфузии, а также эндотелиальные, вазомоторные, нейрогенные, пульсовые и дыхательные колебания на 7-е и 14-е сут эксперимента. Сравнение результатов проводилось попарно между группами с использованием непараметрических критериев Манна–Уитни для независимых выборок и Вилкоксона для сравнений внутри группы, на основании которых рассчитывали показатель статистической значимости р с критическим уровнем равным 0,05. Результаты. Повреждение кожного покрова крыс вызывает стойкие изменения микроциркуляции на периферии раневого дефекта, сопровождается перераспределением роли активных и пассивных механизмов модуляции микрокровотока, а также увеличением показателя перфузии на 27-28% на 7-е и 14-е сут исследования. Закрытие дефекта кожи раневым покрытием без активных компонентов вызывает снижение повышенного показателя перфузии относительно группы сравнения на 5,3% к 7-м и на 13% к 14-м сут. Загрузка камер покрытия таниновой кислотой повышает эффективность нормализации перфузионного показателя к 7-м сут на 11,3%, а уже на 14-е сут данный показатель статистически значимо не отличим от группы контроля. Так же в данной группе к 14-м сут происходит полная нормализация эндотелиальных, нейрогенных и миогенных колебаний. Заключение. Применение полилактидного микрокамерного раневого покрытия, загруженного таниновой кислотой, повышает его эффективность в нормализации показателей микроциркуляции кожи краев раневого дефекта и позволяет ускорить темпы заживления раны. Introduction. The high prevalence of open skin lesions calls for new approaches to treatment of skin wounds. Considering therapeutic and cost efficiency, a polylactide microchamber wound dressing loaded with tannic acid is promising. The dynamics of skin wound healing closely correlates with changes in the microcirculatory system. Aim. To evaluate microcirculatory changes during the application of a polylactide microchamber wound dressing loaded with tannic acid. Methods. The study was performed on 55 white male rats divided into four groups: intact animals (n=10), comparison group (n=15), placebo group (n=15), and experimental group (n=15). An acute, 10×10 mm, excisional skin wound was created in the animals, and it was not subjected to any treatment. Animals of the placebo group were subjected to one application of a microchamber polylactide biodegradable coating without active components on the full-thickness experimental skin defect. Rats of the experimental group were subjected to one application of polylactide biodegradable coating of the same size with microchambers loaded with tannic acid. The state of microcirculation in all experimental groups was assessed by laser Doppler flowmetry. The mean perfusion rate was determined along with the amplitudes of endothelial, neurogenic, myogenic, pulse, and respiratory oscillations on the 7th and 14th days of the experiment. Results were compared using non-parametric Mann-Whitney test for independent samples and Wilcoxon test for dependent variables. A critical p-value of 0.05 was used. Results. The skin damage caused persistent microcirculatory changes at the wound defect periphery. These changes were accompanied by redistribution of the roles of active and passive mechanisms that modulate the microcirculation and by an increase in the perfusion rate by 27-28% by the 7th and 14th days of the study. Closure of a skin defect with a wound dressing without active ingredients caused a decrease in the increased perfusion rate by 5.3% by the 7th day and by 13% by the 14th day vs. comparison group. Loading the coating chambers with tannic acid increased the effectiveness of perfusion rate normalization by 11.3% by the 7th day and caused complete normalization by the 14th day. Also, in this group by the 14th day, there was complete normalization of endothelial, neurogenic, and myogenic fluctuations. Conclusion. Loading a polylactide microchamber wound dressing with tannic acid increases its effectiveness in normalizing the skin microcirculation at the edges of a wound defect and facilitates wound healing.

ОПТИМИЗАЦИЯ СОДЕРЖАНИЯ СЕРЕБРА И СНИЖЕНИЕ РАЗДРАЖАЮЩЕГО ДЕЙСТВИЯ НА МИКРОЦИРКУЛЯЦИЮ АЛЬГИНАТНЫХ МИКРОКАПСУЛ ДЛЯ АДРЕСНОЙ ДОСТАВКИ ВЕЩЕСТВ Савкина А.А. 1 , Ленгерт Е.В. 1 , Ермаков А.В. 1 , Степанова Т.В. 1 , Лойко Д.Д. 1 , Федоров А

Objective: to evaluate the effects of alginate microcapsules on morphological changes in periodontitis depending on silver nanoparticle concentration in them. Materials and Methods. The study was conducted on 30 rats distributed among three groups of 10 animals: the comparison group comprising animals with an experimental model of periodontitis and two experimental groups including animals with 5-week periodontitis, which were subjected to applications of the gel containing microcapsules with high (0.25 M, Group 1) and low (0.1 M, Group 2) concentrations of silver on the surface of their gums. To assess morphological changes, the mandible was sampled for subsequent examination. Results. In animals with periodontitis, changes in the supporting structure of the tooth took place, including defibration and perivascular edema in periodontal ligament of the tooth, and bone resorption via its replacement with connective tissue. The application of a gel containing microcapsules with silver nanoparticles led to a partial reduction of such disorders: particularly, it reduced bone resorption and its replacement with connective tissue. Destructive changes in periodontal tissues caused by gel with a high content of silver nanoparticles (0.25 M) were less pronounced than those caused by capsules with a low content of silver (0.1 M). Conclusion. Gels containing microcapsules with silver nanoparticles contributed to the reduction of destructive changes in the supporting structure of the tooth in periodontitis. The severity of the effects of the gel increased with an increase in the content of silver nanoparticles in alginate microcapsules.

Objective: to study the effect of the targeted delivery system of tannic acid (TA) in silver alginate microcapsules on the state of gum microvasculature in rats with intact periodontium vs. experimental periodontitis. Materials and Methods. The study was conducted on 90 white rats, distributed among six groups: the control group, two groups with intact periodontium and single application of gel with microcapsules loaded/not loaded with TA, experimental periodontitis group, and two groups of animals with periodontitis and repeated application of gel with microcapsules loaded/not loaded with TA. We assessed gingival perfusion and blood flow modulation mechanisms in rats via laser Doppler flowmetry. Results. Applying gel with silver microcapsules to an intact gum in rats caused 7.5% transient increase in perfusion and activation of microcirculation modulation. Loading microcapsules with TA reduced the severity of transient microcirculatory changes. Using gel with TA-loaded capsules in rats with periodontitis allowed achieving a more pronounced normalization of perfusion and mechanisms of microcirculation modulation vs. using gel containing microcapsules without active components. Conclusion. Loading alginate microcapsules with silver ions and TA yielded reduction of the irritating effect on gingival mucosa accompanied by an increase in the effectiveness of correcting microcirculatory disorders in periodontitis.

Relevance. The high prevalence of periodontal diseases, late presentation of patients, especially at the early stages, the ineffectiveness of the provided treatment, and complex still-not-fully-understood mechanisms of the pathogenesis of periodontal diseases render chronic generalized periodontitis (CGP) a socio-medical problem.The study aims to consider the pathogenic mechanisms which characterize the development of CGP.Materials and methods. The study conducted a systematic literature search, which included publications from 2005 to 2022. The studies were found by searching electronic databases PubMed and Google Search.Results. The dental plaque microbiota is a common cause contributing to the initiation of the inflammatory process in the periodontal tissues. But its presence alone is not enough for the manifestation of all periodontal pathological reactions. The principal role in regulating the phases of the inflammation belongs to cytokines and other mediators, the imbalance of which causes the chronification of the process. Microvascular blood flow disorders, which determine the clinical manifestations, are an important part of the pathogenesis at all stages of CGP. Cellular reactions that occur during CGP as a response to the periodontal pathogen invasion protect periodontal tissues and simultaneously induce their destruction, thereby increasing bacterial contamination.Conclusion. The formation of intricately related several key vicious circles, including cytokine, vascular, leukocyte and reparative, is one of the most important particularities of CGP pathogenesis.