scholarly journals Collagen Scaffolds Treated by Hydrogen Peroxide for Cell Cultivation

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4134
Author(s):  
Yuliya Nashchekina ◽  
Pavel Nikonov ◽  
Nataliya Mikhailova ◽  
Alexey Nashchekin

Collagen in the body is exposed to a range of influences, including free radicals, which can lead to a significant change in its structure. Modeling such an effect on collagen fibrils will allow one to get a native structure in vitro, which is important for modern tissue engineering. The aim of this work is to study the effect of free radicals on a solution of hydrogen peroxide with a concentration of 0.006–0.15% on the structure of collagen fibrils in vitro, and the response of cells to such treatment. SEM measurements show a decrease in the diameter of the collagen fibrils with an increase in the concentration of hydrogen peroxide. Such treatment also leads to an increase in the wetting angle of the collagen surface. Fourier transform infrared spectroscopy demonstrates a decrease in the signal with wave number 1084 cm−1 due to the detachment of glucose and galactose linked to hydroxylysine, connected to the collagen molecule through the -C-O-C- group. During the first day of cultivating ASCs, MG-63, and A-431 cells, an increase in cell adhesion on collagen fibrils treated with H2O2 (0.015, 0.03%) was observed. Thus the effect of H2O2 on biologically relevant extracellular matrices for the formation of collagen scaffolds was shown.

2017 ◽  
Author(s):  
Matthew G. Street ◽  
Cristin G. Welle ◽  
Pavel A. Takmakov

AbstractObjectiveNovel therapeutic applications for neural implants require miniaturized devices. Pilot clinical studies suggest that rapid failure of the miniaturized neural implants in the body presents a major challenge for this type of technology. Miniaturization imposes stricter requirements for reliability of materials and designs. Evaluation of neural implant performance over clinically relevant timescales presents time-and cost-prohibitive challenges for animal models.ApproachIn vitro reactive accelerated aging (RAA) was developed to expedite durability testing of these devices. RAA simulates an aggressive physiological environment associated with an immune response and implicated in device failure. It uses hydrogen peroxide, which mimics reactive oxygen species (ROS), and high temperature to accelerate chemical reactions that lead to device degradation. RAA accurately simulates the degradation pattern of neural implants observed in vivo, but requires daily maintenance and is prone to variability in performance.Main resultsThis work introduces automated reactive accelerated aging (aRAA) that is compatible with multiplexing. The core of aRAA is electrochemical detection for feedback control of hydrogen peroxide concentration, implemented with simple off-the shelf components.SignificanceaRAA allows multiple parallel experiments for a high-throughput optimization of reactive aging conditions to more quickly and more rigorously simulate the in vivo environment. aRAA is a cost-effective tool for rapid in vitro evaluation of durability of neural implants, ultimately expediting the development of a new generation of miniaturized devices with long functional lifespans.


1997 ◽  
Vol 62 (6) ◽  
pp. 971-980 ◽  
Author(s):  
Marie Stiborová ◽  
Eva Frei ◽  
Heinz H. Schmeiser

The in vitro enzymatic metabolism of carcinogenic N,N-dimethyl-4-aminoazobenzene, N-nitroso-N-methylaniline and N-nitroso-N,N-dimethylamine was investigated using ram seminal vesicle microsomal prostaglandin H synthase. Both N-nitrosamines are not converted by the studied enzyme. Formaldehyde is produced by the prostaglandin H synthase catalyzed reaction from N,N-dimethyl-4-aminoazobenzene. Arachidonic acid and hydrogen peroxide serve as cofactors for the oxidation of N,N-dimethyl-4-aminoazobenzene. The apparent Michaelis constant and the maximal velocity values for N,N-dimethyl-4-aminoazobenzene as a substrate are 64 μmol/l and 51.2 nmol HCHO/min/mg protein, respectively. In addition to formaldehyde, N-methyl-4-aminoazobenzene and 4-aminoazobenzene, two unknown substances are the products of the N,N-dimethyl-4-aminoazobenzene oxidation. The oxidation of N,N-dimethyl-4-aminoazobenzene catalyzed by prostaglandin H synthase is inhibited by glutathione, ascorbate and NADH. The results suggest that prostaglandin H synthase metabolizes N,N-dimethyl-4-aminoazobenzene through a one-electron oxidation mechanism, giving rise to free radicals.


2020 ◽  
Vol 10 (1) ◽  
pp. 90
Author(s):  
Nur Ariska Nugrahani

Radikal bebas yang berbahaya jika konsentrasi ROS akan meningkat sehingga akan mengakibatkan stress oksidatif. Stress oksidatif biasanya disebabkan oleh konsentrasi tinggi dari radikal bebas dalam sel dan jaringan yang dapat diinduksi oleh beberapa faktor negatif seperti gamma, UV, radiasi sinar-X, tekanan psiko-emosional dan makanan yang tercemar.Untuk meminimalisir radikal bebas dalam tubuh diperlukan antioksidan alami seperti ekstrak buah kiwi dan ekstrak buah apel. Uji aktivitas antioksidan pada masing- masing ekstrak dilakukan dengan metode DPPH (1,1- difenil-2-pikrihidazil). Hasil menunjukkan bahwa nilai IC50 dari ekstrak buah kiwi lebih rendah daripada IC50 ekstrak buah apel. Hal ini menunjukkan bahwa ekstrak buah kiwi mempunyai aktivitas antioksidan lebih kuat dari ekstrak buah apel. Keyword : Radikal bebas, DPPH, Ekstrak buah kiwi, Ekstrak buah apel Free radicals will be dangerous if the ROS concentration will increase and causes oxidative stress. Oxidative stress is usually caused by high concentrations of free radicals in cells and tissues which can be induced by several negative factors such as gamma, UV, X-ray radiation, psycho-emotional pressure and contaminated food. To minimize free radicals in the body natural antioxidants such as kiwi fruit extract and apple extract. The antioxidant activity test on each extract was carried out by the DPPH method (1,1-diphenyl-2-picrihydazyl). The results showed that IC50 value of kiwi fruit extract was lower than IC50 of apple fruit extract. This shows that kiwi fruit extract has stronger antioxidant activity than apple extract. Keyword : free radicals, DPPH, kiwi fruit extract, apple fruit extract


Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 699
Author(s):  
Chigozie E. Ofoedu ◽  
Lijun You ◽  
Chijioke M. Osuji ◽  
Jude O. Iwouno ◽  
Ngozi O. Kabuo ◽  
...  

Numerous reactive oxygen species (ROS) entities exist, and hydrogen peroxide (H2O2) is very key among them as it is well known to possess a stable but poor reactivity capable of generating free radicals. Considered among reactive atoms, molecules, and compounds with electron-rich sites, free radicals emerging from metabolic reactions during cellular respirations can induce oxidative stress and cause cellular structure damage, resulting in diverse life-threatening diseases when produced in excess. Therefore, an antioxidant is needed to curb the overproduction of free radicals especially in biological systems (in vivo and in vitro). Despite the inherent properties limiting its bioactivities, polysaccharides from natural sources increasingly gain research attention given their position as a functional ingredient. Improving the functionality and bioactivity of polysaccharides have been established through degradation of their molecular integrity. In this critical synopsis; we articulate the effects of H2O2 on the degradation of polysaccharides from natural sources. Specifically, the synopsis focused on free radical formation/production, polysaccharide degradation processes with H2O2, the effects of polysaccharide degradation on the structural characteristics; physicochemical properties; and bioactivities; in addition to the antioxidant capability. The degradation mechanisms involving polysaccharide’s antioxidative property; with some examples and their respective sources are briefly summarised.


2020 ◽  
Vol 13 (3) ◽  
pp. 153-158
Author(s):  
Anju G Nagannawar ◽  
M. Jayaraj

Natural products from dietary components such as Indian species and medicinal plants are known to possess antioxidant activity. Antioxidants are inhibitors of oxidation are compounds which prevent the oxidation and in general prolong the life of the oxidizable matter. Majority of the diseases/disorders are mainly linked to oxidative stress due to free radicals. The free radicals (oxidants) are species with very short half-life, high reactivity and damaging activity towards macromolecules like proteins, DNA and lipids. In general, the reactive oxygen species circulating and react with the electron of other molecules in the body and these also affect various enzyme systems and cause damage which may further contribute to conditions such as cancer, ischemia, ageing, adult respiratory distress syndromes, rheumatoid arthritis etc. Dietary plants contain variable amounts of antioxidants. It has been proved that plant antioxidants may contribute to the beneficial health effects of dietary plants. The present study was to evaluate antioxidant activity of ethanolic extract of iv vivo whole plant and in vitro leaf callus of Mollugo oppositifolia L. is an important traditional medicinal herb belonging to the family Molluginaceae using 2,2-diphenyl-1-Picrylhydrazyl (DPPH) radical scavenging assays. The results obtained showed that the ethanolic extracts of whole plant in vivo and in vitro leaf callus showed significant DPPH activity with IC50 value of 52.82± 0.0017 μg/mL and 58.66±0.004μg/mL respectively, while IC50 of vitamin C as standard was 84.84±11.54μg/mL. Present study revealed that an antioxidant activity was higher leaf callus extract compare to whole plant extract of Mollugo oppositifolia L.


Author(s):  
Mohd Abu Zaid Yamini Anand

Abstract-The changing lifestyle and environment conditions have predisposed common man towards numerous diseases. Today most of the diseases are said to be caused by synthetic chemicals, toxic heavy metals, and the stress of modern living. It is also true that oxygen is essential for sustaining life but it is also dangerous to our existence. Oxygen is being viewed as playing a lead role in the generation of reactive intermediates, thereby causing cellular damage. Our body has the mechanism to handle free radicals and prevent its damaging effect, which involves the use of antioxidants as glutathione and antioxidant enzymes assuperoxidedismutase,catalase,glutathioneperoxidaseglutathionereductase, glutathione-S-transferase to counter these free radicals. When the redoxstatus of the body is overwhelmed by these radical species, this may result in variety of chronic diseases and even premature senility.The administration of natural antioxidant as food constitutes or therapeutic agents is looked-for to neutralize these reactive oxygen species and prevent or delay diseased condition caused by these reactive species. Most exogenous antioxidants come from raw vegetable fruits, spices, herbsandvariousmedicinalplants.Naturalantioxidants are always appreciated over synthetic ones because they lack toxic side effects. The present study deals with the effectsofStevia rebaudiana leaf extract on the statusantioxidant of RBC as evident by an in vitro dose-dependent decrease in the activity of erythrocytes superoxide dismutaseand catalase as compared to the normal control whereas at much higher concentration ofstevialeaf extract (100μg/ml)started to show a reversingtrendofitsprotectiveaction.


2019 ◽  
Vol 2 (1) ◽  
pp. 1-5
Author(s):  
Siti Sarah Bintang Sarah Bintang ◽  
Yahwardiah Siregar ◽  
Muhammad Ichwan

Abstract Oxidative stress occurs due to imbalance of free radicals over antioxidant level in the body. This condition causes lipid peroxidation and DNA damage. D-Galaktosa is The mechanism of oxidative stress induced by d-galactose occurs in the subcellular, especially in the brain's mitochondria. Increasing the concentration of d-galaktosa is oxidized by galaktosa oxidase to form hydrogen peroxide (H202) which causes a decrease in superoxide dismutase (SOD). H202 reacts with reduced iron and forms hydroxide ions (OH-). Objective: The aim of this study was to determine the effect of d-galaktosa induction on oxidative stress levels (MDA) in male mice. Methods: Methods of samples of mice given d-galaktosa and blood collection from the heart were carried out at the Pharmacology Laboratory of the Faculty of Medicine, University of North Sumatra. Results: The results showed that administration of d-galaktosa, through intraperitonial injection every day for 6 weeks, had an effect on the levels of oxidative stress in male mice. Conclusion: The results of this study indicate that administration of d-galaktosa, through intraperitonial injection every day for 6 weeks, has an effect on levels of oxidative stress in male mice.


Author(s):  
A. A. Safonov ◽  
I. S. Nosulenko

The process of studying free radicals began in the middle of the last century (the free radical theory of aging in 1956). Multiple studies have revealed the effect of free radicals on the cells of the body and the development of various diseases, such as diabetes, autoimmune diseases, diseases of the nervous system, and others. As a result, the term antioxidant has emerged, compounds that reduce and prevent the effects of free radicals. Most of the newly synthesized substances are studied for their antiradical properties. 1,2,4-Triazole derivatives are no exception, which has already proven themselves as biologically active compounds. The aim of this work was the investigation antiradical activity among 4-amino-5-(thiophen-2-ylmethyl)-4H-1,2,4-triazole-3-thiol derivatives. Materials and methods. Previously synthesized 4-amino-5-(thiophen-2-ylmethyl)-4H-1,2,4-triazole-3-thiol derivatives were used as test compounds. The research of antiradical activity was based on the interaction between 4-amino-5-(thiophen-2-ylmethyl)-4H-1,2,4-triazole-3-thiol derivatives and 2,2-diphenyl-1-picrylhydrazyl (DPPH) in vitro. DPPH is a stable free radical. The color of its alcoholic solutions were intense purple (λmax = 517 nm). When DPPH interacted with compounds that were capable of scavenging free radicals, it produced products. These products are yellow in color and do not absorb light of the aforementioned wavelength. The study was carried out according to the method. Results. The antiradical activity of 10 new 4-amino-5-(thiophen-2-ylmethyl)-4H-1,2,4-triazole-3-thiol derivatives was studied. Most of the test compounds show antiradical activity against DPPH. Compound 1 was the most active at a concentration of 1 × 10-3 M and the antiradical effect was close to ascorbic acid. Conclusions. The most active compound is 4-amino-5-(thiophen-2-ylmethyl)-4H-1,2,4-triazole-3-thiol, which in a concentration of 1 × 10-3 M has an antiradical effect in 88.89 %. When reducing the concentration to 1 × 10-4 M, also reduces the antiradical activity to 53.78 %. Some conclusions are drawn regarding the “structure – effect” dependence between 4-amino-5-(thiophen-2-ylmethyl)-4H-1,2,4-triazole-3-thiol derivatives: – the introduction of 4-fluorobenzylidene radical (compound 2) into the 4-amino-5-(thiophen-2-ylmethyl)-4H-1,2,4-triazole-3-thiol molecule results in a slight decrease in activity; – the introduction of 2-hydroxybenzylidene radical (compound 3) into initial molecule results a high antiradical effect, which hardly changes with decreasing concentration; – transformation to 2-((5-(thiophen-2-ylmethyl)-4-((R)amino)-4H-1,2,4-triazol-3-yl)thio)acetic acid has almost no effect on antiradical activity, except for compound 9 (the antiradical effect is reduse).


1969 ◽  
Vol 22 (2) ◽  
pp. 343 ◽  
Author(s):  
RW Parish

The formation of lignin was determined in wheat internodes incubated with ferulic acid, hydrogen peroxide, and various concentrations of indoleacetic acid (IAA). lAA was found to markedly inhibit lignification in the lower two-thirds of the internode. Experiments which were carried out in vitro utilized the polymerization of free radicals, formed after eugenol had been oxidized by peroxidase and hydrogen peroxide, as a model system for lignification. The polymerization was inhibited considerably by IAA. A mechanism is postulated to explain the effects of lAA.


2019 ◽  
Vol 9 (4-A) ◽  
pp. 207-211
Author(s):  
Shilpa Dhaniya ◽  
Suman Kumari Parihar

Dicoma tomentosa and Alhagi maurorum are perennial herbaceous plant having multiple medicinal health benefits. The free radicals are generated in the body as metabolic products of several reactions. These free radicals cause multiple harms to the cell, on their cell wall, to the DNA and cause number of diseases. In the present study, the plants were selected and collected from Rajasthan and were shade-dried. The powder was formed of leaves and stem of both the plants. The methanolic extract was prepared for further studies and the enzymatic and non-enzymatic potential of evaluated through their standard protocols. Dicoma tomentosa and Alhagi maurorum both showed strong antioxidant potential. While comparing both the plants with standard, the stem of Dicoma tomentosa was found having comparatively strong antioxidant potential. Keywords: Alhagi maurorum, Dicoma tomentosa, antioxidant potential, in-vitro study, comparative evaluation.


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