EFFECT OF MELANINE-BASED PHARMACOLOGICAL COMPOSITION ON HEALING OF LINEAR CUT SKIN WOUNDS IN RATS AND ITS BIOMECHANICAL PROPERTIES Текст научной статьи по специальности «Фундаментальная медицина»

MEDICAL SCIENCES

ВПЛИВ ФАРМАКОЛОГ1ЧНО1 КОМПОЗИЦП НА ОСНОВ1 МЕЛАН1НУ НА ГОСННЯ Л1Н1ЙНИХ Р1ЗАНИХ РАН ШК1РИ У ЩУР1В ТА II Б1ОМЕХАН1ЧН1 ВЛАСТИВОСТ1

Грицевич Н.Р.

Вищий навчальний комунальний заклад Львiвськоi обласно'1' ради «Львiвська медична академiя iMem

Андрея Крупинського», к.мед.н., асистент кафедри

НШтша Н.С. ННЦ «1нститут бюлогИ та медицини» Кшвського нацiонального ymiверситету iменi Тараса Шевченка, аспiрант

Степанова Л.1. ННЦ «1нститут бюлогИ та медицини» Кшвського нацiональногоymiверситету iменi Тараса Шевченка, к.б.н., ст.н.сп.

Гончаров М.П.

Вищий навчальний комунальний заклад Львiвськоi обласно'1'ради «Львiвська медична академiя iменi

Андрея Крупинського», асистент кафедри

Верещака В.В. ННЦ «1нститут бюлогИ та медицини» Кшвського нацiонального }miверситету iменi Тараса Шевченка, д.б.н., ст.н.сп.

EFFECT OF MELANINE-BASED PHARMACOLOGICAL COMPOSITION ON HEALING OF LINEAR CUT SKIN WOUNDS IN RATS AND ITS BIOMECHANICAL PROPERTIES

Hrytsevych N.

Higher educational communal institution of the Lviv regional council "Andrei Krupinsky Lviv Medical

Academy", phD, assistant Nikitina N.

ESC "Institute of Biology and Medicine " Taras Shevchenko National University of Kyiv, PhD student

Stepanova L.

ESC "Institute of Biology and Medicine " Taras Shevchenko National University of Kyiv, PhD, senior researcher Goncharov M.

Higher educational communal institution of the Lviv regional council "Andrei Krupinsky Lviv Medical

Academy", assistant Vereschaka V. ESC "Institute of Biology and Medicine " Taras Shevchenko National University of Kyiv, Doctor of medical sciences, senior researcher

Анотащя

В хрошчних експериментах на щурах з моделюванням лшшних pi3aHm ран шшри показано, що щодення !х обробка гелем карбополу з меланшом прискорюе та вщновлюе мщнють шшри та и еластич-нють, що проявляеться у таких бюмехашчних властивостях шшри як розривне навантаження та вщносне подовження. Препарат порiвняння гель Пантестин-Дарниця також справляв позитивний вплив на гоення ранового процесу та розривне навантаження. Порiвняння ефекпв фармаколопчно! композици на основi мелашну та гелю Пантестин-Дарниця показало, що дiя фармаколопчно! композици на основi меланшу була бшьш вираженою. Abstract

Daily treatment with carbopol gel with melanin accelerates and restores skin strength and elasticity in chronic experiments on rats with simulations of linear cut skin wounds were shown. It manifested in such biomechanical properties of the skin as breaking load and elongation. The Pantestin-Darnitsa gel also had a positive effect on wound healing and rupture as comparison drug. Comparison of the effects of melanin-based pharmacological composition and Pantestin-Darnitsa gel showed that the effect of melanin-based pharmacological composition was more pronounced.

Ключов1 слова: лшшш рiзанi рани шшри, гель карбополу з меланшом. Keywords: linear cut skin wounds, melanin-based pharmacological composition

Introduction

The electronic database PubMed Central for the search words «drugs for wounds» includes 108,329 scientific papers, most of it has been published in recent years, which indicates the relevance of the development of new dermatotropic drugs. Analysis of the results obtained by other scientists showed that their efforts were aimed at developing universal drugs with a combined mechanism of action and a safe carrier, which causes antimicrobial, anti-inflammatory, analgesic, dehydrating, necrolytic and osmotic effects on infected wounds. The literature review [1] lists the above requirements for modern dermatotropic drugs, as well as materials used in their production. The authors described both the advantages and disadvantages of the components included in the combined drugs. Analysis of modern literature showed the absence of a universal dermato-tropic agent. As for the carrier for active substances in such preparations, the work of Zhang L. et al., in which the discussion about the benefits of hydrogel dressings were completed in favor of the latter [2]. The antimicrobial effect of drugs achieve by the introduction of various antibiotics, which may develop antibioticresistance to microorganisms, and in some cases, patients may develop an allergic reaction to the antibiotic.

We were shown that our developed pharmacological composition (carbopol gel based on melanin has an effective wound-healing effect on full-thickness and purulent-necrotic wounds due to anti-inflammatory, an-tioxidant, antimicrobial action [3, 4]. The effect on the healing of linear cut skin wounds in rats and its biome-chanical properties remained unexplored.

The aim of the research was to investigate the effect of melanin-based pharmacological composition and the comparison drug Pantestin-Darnitsa gel on the duration of healing of linear cut skin wounds in rats and its biomechanical properties.

Material and methods of research

All experimental protocols were approved by the Ethical Committee for Conduction of Animal Studies at the Educational and Scientific Center 'Institute of Biology' of Taras Shevchenko National University of Kyiv, Ukraine. The studies were performed on 32 white nonlinear laboratory rats, which were randomly divided into 4 groups of 8 animals each. The first group of healthy rats, in which the wounds were not modeled -intact controls. The second group of rats with linear cut

Dynamics of healing

wounds without treated and their healing occurred independently - control. In the third group of rats linear cut wounds were treated twice a day with melanin-based pharmacological composition (0.5% solution of carbopol, in which melanin was dissolved). The concentration of melanin in the carbopol solution was 0.1%. The producer of melanin is the Antarctic black yeast Pseudonadsoniella brunnea 470 FCKU [6, 7]. In the fourth group of rats, linear cut wounds were treated twice a day with the comparison drug Pantestin-Darnitsa gel.

Linear cut wounds were reproduced on epilated skin in anesthetized rats. The skin was cut using surgical scalpel, 40 x 1 mm2. Treatment begun immediately after wounds reproduction until healing.

Black yeasts as a valuable source of pigments, in particular melanin, have significant advantages over plants and animals (from which pigments are derive), because the development of producer microorganisms does not depend on seasonal restrictions, it does not compete for habitat with other organisms and can actively grow in cheap culture medium, while synthesizing pigments in the required (high) amount. This makes such a bioprocess economically viable on an industrial scale and promising for use in the medical field.

The dynamics of wound healing in rats of all groups was studied. On the day of complete healing, the animals were killed and examined for biomechanical characteristics of the skin in the area of wound by establishing the rupture load (weight of the sample at which the skin ruptured) and the relative elongation of the standard back skin sample of 40 mm2 (40 x 1 mm) [8].

Statistical analysis of data was carried out by the "Statistica 8.0" software package. Shapiro-Wilk's W criterion was used for the investigation of the data distribution type. Posthoc analysis included Student's t-test for parametric data. Whereby differences P< 0.05 were deemed reliable [9].

Results and discussion

As a result of our researches it was established that complete healing of linear cut wounds of skin in rats of control group took place on the 16th day (Tab. 1). In the group of rats with linear cut wounds after treated twice a day with melanin-based pharmacological composition, complete healing occurred on 12th day. In the group of with linear cut wounds after treated twice a day with the comparison drug Pantestin-Darnitsa gel, complete healing occurred on the 14th day.

Table 1

linear cut wounds

Group Day Wound area, mm2

Control Melanin-based pharmacological composition Pantestin-Darnitsa gel

0 40,0 ± 1,16 40,0 ± 1,0 40,0 ± 1,0

6 36,5±2,23 35,6±1,9 35,8±2,2

9 21,5±4,28 13,3,1±3,1** 18,4±4,9*,#

12 15,7±2,12 Full healing** 8,5 ±2,1**,#

14 6,1 ± 1,08 Full healing *

16 Full healing

*-p<0,05, **-p<0,01 compared to control, # - p<0,05 compared to group after melanin-based pharmacological composition treatment.

Melanin-based pharmacological composition had a positive effect on the tensometric characteristics of the skin (Tab. 2). If the rupture load in the control group of rats decreased by 48.5% (p <0.05) compared with intact rats, in the group of rats with linear cut wounds after treated melanin-based pharmacological composition, the rupture load increased to the level of intact control.

Pantestin-Darnitsa gel also had a positive effect on the strength of the skin, which was reduced after surgery. Under its action, the rupture load, although not reaching the level of intact, increased by 39.3% (p <0.05) compared to control.

Table 2

The effect of melanin-based pharmacological composition on the biomechanical properties of rat skin after heal-

A similar pattern was observed when measuring the relative elongation of the skin sample. In control rats in which self-healing occurred, the relative elongation decreased by 14.9% (p <0.05) compared with intact animals. Carbopol gel with melanin restored the studied index to the level of intact control, which indicates the restoration of skin elasticity after application of the gel with melanin.

Pantestin-Darnitsa gel did not have a statistically significant effect on the relative elongation of the skin, so the elasticity of the skin after healing was the same as in control rats.

Indicators Group

Intact Control (wounds) Wounds+ melanin-based pharmacological composition Wounds + Pantestin-Darnitsa gel

Rupture load, g/cm2 258,6+21,3 133,1+25,0* 245,4+17,4# 185,4+21,8*/#

Relative elongation, % 20,1+0,9 17,1+0,8* 19,5+0,4# 16,8+0,5*

-p<0,05 compared to intact, # - p<0,05 compared to control.

*

It is well known that the strength and elasticity of the skin is provide by collagen, which is the main protein of connective tissue. The amino acid composition of collagen is strikingly different from other proteins. It contains 20% of proline and oxyproline. Only 1% of free oxyproline is detected in the skin. The increase in its concentration is evidence of collagenolysis in the skin [10].

The strength and elasticity of the skin is also provide by proteoglycans, the hydrolysis products of which are hexuronic acids. We hypothesized that after self-healing, the content of oxyproin and hexuronic acids in the wound area increases, indicating a reduced content of collagen and proteoglycans in the scar area. The use of melanin-based pharmacological composition, obviously, prevents collagenolysis and degradation of proteoglycans, which helps to restore the organization of connective tissue and biomechanical properties of the skin.

Conclusions

Thus, melanin-based pharmacological composition has been shown to accelerate the healing of linear cut skin in rats and restore its strength and elasticity, which is manifested in such biomechanical properties of the skin as rupture load and elongation. Pantestin-Darnytsia gel also had a positive effect on wound healing and rupture. Comparison of the effects of the melanin-based pharmacological composition and Pantestin-Darnitsa gel showed that the effect of the melanin was more pronounced.

References

1. Zaghazadeh S., Rinoldi C., Schot M. et al. Drug Delivery Systems and Materials for Wound Healing Applications. Adv Drug Deliv Rev. 2018; 127: 138166.

2. Zhang L., Yin H., Lei X. et al. A Systematic Review and Meta-Analysis of Clinical Effectiveness and Safety of Hydrogel Dressing in the Management of Skin Wounds. Front Bioeng Biotechnol. 2019; 7: 342

3. Dranitsina A., Taburets O., Dvorshchenko K., Grebinyk D., Beregova T., Ostapchenko L. Tlr2, Tjplgenes expression during dynamics of wound healing and with the treatment of melanin. Current Issues in Pharmacy and Medical Sciences. 2017; 30(2): 81-85.

4. Nikitina NS, Stepanova LI, Vereshchaka VV, Savchuk OM, Beregova TV Influence of carbopol gel with melanin on the content of cytokines in the wound substrate of full-layer excised planar skin wounds in rats. Bulletin of problems of biology and medicine.2019; 2(1) (150): 168-171.

5. Taburets O.V., Morgaienko O.O., Kondratiuk T.O., Beregova T.V., Ostapchenko L.I. The effect of "Melanin-gel" on the wound healing. Research Journal of Pharmaceutic, Biological and chemical sciences. 2016; 7(3): 2031-2036.

6. Kondratiuk T.O., Kondratyuk S.Y., Khimich M.V., Beregova T.V., Ostapchenko L.I. Confirmation of taxonomic status of black yeast-like fungus by three gene phylogeny. Acta Botanica Hungarica. 2016; 59(3-4): 287-302.

7. Kondratiuk T., Beregova T., Taburets O., Akulenko T., Ostapchenko L. Microscopic fungi in the collection of FCKU NSC "Institute of Biology and Medicine" of Taras Shevchenko National University of Kyiv - use in experimental research. Bulletin of Lviv University. The series is biological. 2018; 79: 100-103.

8. Khmil DO, Kostenko VO The role of NO-synthase and arginase in the mechanisms of connective tissue disorganization in rats under conditions of excessive sodium nitrate intake. The world of biology and medicine. 2017; 60(2): 169-171.

9. Rebrova OYu. Statistical analysis of medical 10. Tseluyko S. S., Malyuk E. A., Korneeva L. S.

data. Application of application package Morfofunktsionalnaya harakteristika dermyi kozhi i STATISTICA. M.: Media Sphere 2002: 312. ego izmeneniya pri starenii. Byull. fiziol. i patol.

dyihaniya. 2016; 60: 111-116.

MODERN PEDAGOGICAL APPROACHES TO THE EDUCATIONAL PROCESS DURING THE TEACHING OF "ORTHODONTICS" TO FOREIGN STUDENTS

Kotelban A.

PhD, Associate Professor of the Department of Pediatric Dentistry

Bukovynian State Medical University

Moroz P.

PhD, Assistant of the Department of Surgery № 1 Bukovynian State Medical University

Abstract

Today the development of medical education in Ukraine and the world requires new approaches to the organization of the pedagogical process. One of the methods of emotional stimulation of learning is the introduction of one's own clinical situations into the educational process, as well as examples of successful careers of famous orthodontists. This pedagogical approach demonstrates the importance of the profession, increases student motivation to learn and affects the personal and professional development of future doctors. You can also use the method of cognitive discussion to stimulate interest in learning. Thus students are divided into supporters and opponents of this or that explanation of a clinical case that directly stimulates the maximum concretization of knowledge. Simulation training allows to increase the assimilation of educational material, quality and efficiency of the educational process and, most importantly, to practice the skill on a mannequin, which contributes to the formation of students' motivation to learn.

Thus, the teacher's main task is to teach the student to hear, see the information received, and more importantly - to speak. The vast majority of modern students have a small vocabulary, inability to express their thoughts, especially when it comes to scientific material with complex special terminology.

Keywords: pedagogy, medical university, students, orthodontics.

Today the development of medical education in Ukraine and the world requires new approaches to the organization of the pedagogical process [1-8]. After all, it is the student's independent work during study and practice that distinguishes the educational process of higher education from secondary education. This independence involves the entire educational process, both at home and in lectures and practical classes. In the independent work of the student his individual features are determined, which he inherited and acquired in the family, school and team. He has already created his own dynamic stereotype in the system of work, study, daily routine, and now under new conditions, in another country, he needs to change it and create a new one [13].

You have to overcome yourself in many ways, change some habits, and sometimes develop new ones. In our opinion, a qualitative indicator of improving learning outcomes among foreign students is, above all, the creation of a proper learning microclimate in the group and the education of positive emotions about learning activities, its forms and methods [3-6].

The method of cognitive discussion can also be used to stimulate interest in learning. In this case, students are divided into supporters and opponents of a particular explanation of the clinical case, which directly stimulates the maximum concretization of knowledge [1, 3, 6].

The most striking example of this method is the discussion of indications and contraindications to the choice of orthodontic appliance design or orthodontic

diagnosis based on the demonstration of models of patients' jaws, as well as photographs and X-rays. This type of work in the classroom allows you to justify and objectively prove your position.

When solving situations, students learn to act in a "team", to analyze the educational clinical situation and choose the best option in the context of the problem.

Of course, an important point is to increase student motivation to learn. To achieve this goal, first of all, there is the introduction of their own clinical situations, as well as examples of successful careers of famous orthodontists. This pedagogical approach demonstrates the importance of the profession, increases student motivation to learn and affects the personal and professional development of future doctors. Secondly, and most importantly, it is necessary to show each student the results of treatment [1-6].

In orthodontics, this is easily achieved by demonstrating models of patients' jaws, as well as photographs and X-rays before and after orthodontic treatment with various methods and devices. It is necessary that each student of the group heard and saw this material. It is better for a group to use a computer with a multimedia projector. Models of the jaws of orthodontic patients are more suitable for individual training, showing and explaining each pair of models to each student takes a long time, and if you demonstrate this from the teacher's desk, not all students will be able to consider the details.

In our opinion, a qualitative indicator of improving learning outcomes can be the creation of a proper learning microclimate in the group. The teacher at the