Dentin bond strength and antimicrobial activities of universal adhesives containing silver nanoparticles synthesized with Rosa canina extract.

OBJECTIVE: The purpose in the study was to evaluate the effect of biogenic silver nanoparticles (Ag NPs) synthesized by the green synthesis method on dentin bond strength in three different universal adhesives and investigate their antibiofilm activity against Streptococcus mutans (S. mutans). MATERIALS AND METHODS: Three different universal adhesives (single bond universal, all-bond universal, and clearfil universal) were used in this study. Ag NPs were synthesized using rose hip (Rosa canina) extract as a reducing and stabilizing agent and they were characterized with STEM, UV-vis spectrophotometer, DLS, and zeta potential. Ag NPs were added to the adhesive resins at a rate of 0.05% (w/w), and their homogeneous distribution in the adhesive was determined using EDX spectrometry. Samples in all groups were tested at baseline-after 5000 and 10,000 thermal cycles. Adhesive composite discs were used for the live/dead analysis of S. mutans, MTT metabolic activity test, lactic acid production, and determination of colony-forming unit (CFU) values (n = 3). Ninety extracted caries-free human third molars were used to determine microtensile bond strength (µTBS) (n = 10). After the universal adhesive was applied to the dentin surface, composite resin (Z550 XT, 3 M ESPE, USA) was placed and sections were taken to form a composite-dentin stick of 1 mm × 1 mm wideness and 8-mm length. The sticks were broken at a rate of 1 mm/min under uniaxial tension in a universal testing machine, and the failure modes were determined by SEM. One-way analysis of variance (ANOVA) for antibacterial tests and two-way analysis of variance for µTBS tests were performed (p < 0.05). RESULTS: All universal adhesive groups containing Ag NPs showed higher antibacterial activity than control groups without Ag NPs (p < 0.05). There was a statistically significant difference in the live/dead assay analysis, MTT metabolic activity test, lactic acid production, and CFU values in the thermal cycled Ag NPs groups (p < 0.05). Antibacterial activity decreased in groups containing Ag NPs subjected to 10,000 thermal cycles. The highest lactic acid production 11.06 (± 0.629) and CFUs 7.61 (± 0.304), live bacteria 31.13 (± 0.466), and S. mutans MTT metabolic activity 0.29 (± 0.376) at AU (All-Bond Universal-Ag NPs) 10,000 thermal cycles group. There was no difference in µTBS values between the initial and 5000 thermal cycle groups, there was a difference between the 10,000 thermal cycle groups. The CU (Clearfil Universal-Ag NPs) group subjected to 10,000 thermal cycles showed lower µTBS 11.1 (± 3.2). CONCLUSION: In conclusion, universal adhesives containing biogenic Ag NPs showed higher antibacterial activity than the control groups and did not reduce the µTBS. CLINICAL RELEVANCE: Antibacterial universal adhesives can contribute to restoration success in clinical applications by reducing residual bacteria and preventing secondary caries formation.

[6]-Shogaol and [6]-Gingerol active ingredients may improve neuropathic pain by suppressing cytokine levels in an experimental model.

Background/aim: Neuropathic pain (NP) is a type of chronic pain usually caused by damage to the somatosensory system. Bioactive antioxidant compounds, such as curcumin and ginger, are widely preferred in the treatment of NP. However, the ingredient-based mechanism that underlies their pain-relieving activity remains unknown. The aim of this study was to investigate the therapeutic effects of trans-[6]-Shogaol and [6]-Gingerol active ingredients of the Zingiber officinale Roscoe extract on the spinal cord and cortex in the neuroinflammatory pathway in rats with experimental sciatic nerve injury. Materials and methods: Forty-six volatile phenolic components were identified in ginger samples using gas chromatography-mass spectrometry analysis. Thirty 3-month-old male 250-300 g Wistar Albino rats were divided into three groups as (i) sham, (ii) chronic constriction injury (CCI), and (iii) CCI+ginger. NP was induced using the CCI model. A ginger extract treatment enriched with trans-[6]-shogaol and [6]-gingerol active ingredients was administered by gavage at 200 mg/kg/day for 7 days. On the 14th day of the experiment, locomotor activity was evaluated in open field and hyperalgesia in tail flick tests. Results: In behavioural experiments, a significant decrease was observed in the CCI group compared to the sham group, while a significant increase was observed in the CCI+ginger group compared to the CCI group (p < 0.05). In the spinal cord and cortex tissues, there was a significant increase in the TNF-α, IL-1ß, and IL-18 neuroinflammation results of the CCI group compared to the sham group, while there was a significant decrease in the CCI+ginger group compared to the CCI group. Conclusion: In this study, ginger treatment was shown to have a therapeutic effect on neuroinflammation against sciatic nerve damage.

Novel Anthocyanin-Based Colorimetric Assay for the Rapid, Sensitive, and Quantitative Detection of Helicobacter pylori.

Several different diagnostic tests have been reported for rapid, sensitive, and economical detection of bacterial pathogens, but most lack widespread and practical use in the clinic. In this study, we used anthocyanins from red cabbage (Brassica oleracea) as a natural pH indicator and, for the first time, incorporated this agent into a simple, rapid, and economical colorimetric strategy for the detection of Helicobacter pylori (H. pylori) (RCE@test). We prepared two sets of RCE@test solutions (test 1 is purple, and test 2 is blue) in different forms, including liquid, adsorbed filter paper, and agar, and investigated the performance of each RCE@test as a function of the test volume, H. pylori concentration, and reaction time. To elucidate the effect of the pathophysiological environment on these RCE@tests, H. pylori in an artificial gastric fluid was also detected. The 10 and 1 CFU/mL H. pylori suspensions were detected in 15 min and 3 h, respectively, and the limit of detection was determined down to 1 CFU/mL. We experimentally demonstrated the advantages of the RCE@test for detection of H. pylori by comparing it to a commercially available rapid urease test, the "CLO test (Campylobacter-like organism test)". In addition to colorimetric detection by the naked eyes, RGB (Red Green Blue) and Delta-E analysis in image-processing software was run to quantitatively monitor changes of color in the RCE@test using a smartphone application. Finally, we propose that this test provides simple, effective, rapid, and inexpensive detection and that it can be easily implemented for clinical use.

Effects of Transcranial Direct Current Stimulation on Motor and Cognitive Dysfunction in an Experimental Traumatic Brain Injury Model.

AIM: To investigate the therapeutic and neuroprotective effects of transcranial direct current stimulation (tDCS) application on the traumatic brain injury (TBI)-induced glutamate and calcium excitotoxicity and loss of motor and cognitive functions. MATERIAL AND METHODS: Forty rats were equally divided in the sham, TBI, tDCS + TBI + tDCS, and TBI + tDCS groups. Mild TBI was induced by dropping a 450-g iron weight from a height of 1 m onto the skull of the rats. The tDCS + TBI + tDCS group was prophylactically administered 1 mA stimulation for 30 min for 7 days starting 5 days before inducing TBI. In the TBI + tDCS group, tDCS (1 mA for 30 min) was administered 2 h after TBI, on days 1 and 2. Cognitive and locomotor functions were assessed using the novel object recognition and open field tests. The calcium, glutamate, and N-methyl-D-aspartate receptor 1 (NMDAR1) levels in the hippocampus were measured using enzyme-linked immunosorbent assay. RESULTS: Although the motor and cognitive functions were substantially reduced in the TBI group when compared with the sham, they improved in the treatment groups (p < 0.05). The calcium, glutamate, and NMDAR1 levels were considerably higher in the TBI group than in the sham (p < 0.001). However, they were considerably lower in the tDCS + TBI + tDCS and TBI + tDCS groups than in the TBI groups (p < 0.05). In particular, the change in the tDCS + TBI + tDCS group was higher than that in the TBI + tDCS group. CONCLUSION: Application of tDCS before the development of TBI improved motor and cognitive dysfunction. It demonstrated a neuroprotective and therapeutic effect by reducing the excitotoxicity via the regulation of calcium and glutamate levels.

Red cabbage extract-mediated colorimetric sensor for swift, sensitive and economic detection of urease-positive bacteria by naked eye and Smartphone platform.

The bacterial pathogens have caused various serious infectious diseases in the human body, and even some threats to human life by leading to deaths. Enterobacteriaceae species especially urease positive ones, Proteus mirabilis (P. mirabilis) and Klebsiella pneumoniae (K. pneumoniae), show resistance to antibiotics and cause respiratory and urinary tract infections. We have developed natural indicator-incorporated colorimetric urease tests with a naked eye and smartphone readout to rapidly, sensitively and economically detect P. mirabilis and K. pneumoniae. We utilized anthocyanin found as a predominant component in red cabbage (Brassica oleracea) extract as a natural pH indicator instead of toxic and synthetic indicators. As a mechanistic explanation for the detection of P. mirabilis and K. pneumoniae, urease enzymes secreted from the P. mirabilis and K. pneumoniae hydrolyze urea to produce ammonia (NH3), which increases the pH value of the reaction environment and leads to deprotonation from anthocyanins. The changes in the molecular structure and electronic structure of anthocyanins are responsible for revealing many different colors. We demonstrated how some reaction parameters including the concentration of the bacteria (colony-forming unit, CFU), the concentration of anthocyanin in the tests, initial color and pH values (pHs) of the tests influence their detection performance. We further developed a 3D-printed smartphone platform with smartphone based digital image processing software to improve the detection limit and shorten the detection time. We claim that natural indicator-incorporated rapid urease tests providing colorimetric readout evaluated by the human eye and smartphone imaging processing has great potential in practical use and they can be implemented in clinics.

Recent Advances in Colorimetric Tests for the Detection of Infectious Diseases and Antimicrobial Resistance.

Diagnosis of infection-causing microorganisms with sensitive, rapid, selective and economical diagnostic tests is critical to start the right treatment. With these tests, the spread of infections can be prevented. In addition to that, the detection of antimicrobial resistance also makes a significant contribution to public health. In recent years, different types of diagnostic tests have been developed as alternatives to traditional diagnostic tests used in clinics. In particular, colorimetric tests, which minimize the need for an instrument, have advantages owing to their cost effectiveness, rapid response and naked-eye detection and practical use. In this review, we especially focused on pH indicators and nanomaterial-based colorimetric tests in detection of infection-causing microorganisms and antimicrobial resistance.

Synthesis of taurine-Cu3(PO4)2 hybrid nanoflower and their peroxidase-mimic and antimicrobial properties.

Herein, we report the synthesis of taurine incorporated (sulfur containing organic molecule derived from methionine and cysteine) hybrid nanoflowers (thNFs) with an intrinsic peroxidase-mimic and antimicrobial activities in the presence of H2O2. Formation of thNFs using non-enzyme molecules was for the first time and systematically studied as a function of the taurine concentration, types of metal ions (Cu2+, Fe2+ and Fe3+) and pH values of reaction solution. The peroxidase like activities of thNFs rely on Fenton-like reaction against guaiacol used as a model substrate. The efficiency of Fenton reaction can be attributed to porous structure and presence of ions of transition elements in the thNFs. The thNFs were further characterized using FTIR, XRD, SEM and EDX. The thNFs also showed remarkable antimicrobial properties against S. aureus, E. coli, B. cereus and C. albicans. We claim that nonprotein-based NFs can be considered as new generation nano-biocatalysts as an alternative to enzymes and can be used in various medicinal, biochemical, immunological, biotechnological, and industrial applications.

Can food and food supplements be deployed in the fight against the COVID 19 pandemic?

BACKGROUND: Due to lack of approved drugs and vaccines, the medical world has resorted to older drugs, produced for viral infections and other diseases, as a remedy to combat COVID-19. The accumulating evidence from in vitro and in vivo studies for SARS-CoV and MERS-CoV have demonstrated that several polyphenols found in plants and zinc- polyphenol clusters have been in use as herbal medicines have antiviral activities against viruses with various mechanisms. SCOPE OF REVIEW: Curcumin, zinc and zinc-ionophores have been considered as nutraceuticals and nutrients showing great antiviral activities with their medicinal like activities. MAJOR CONCLUSIONS: In this work, we discussed the potential prophylactic and/or therapeutic effects of curcumin, zinc and zinc-ionophores in treatment of viral infections including COVID-19. GENERAL SIGNIFICANCE: Curcuminoids and Zinc classified as nutraceuticals under GRAS (Generally Recognized As Safe) by FDA can provide complementary treatment for COVID 19 patients with their immunity-boosting and antiviral properties.

Investigation of ellagic acid rich-berry extracts directed silver nanoparticles synthesis and their antimicrobial properties with potential mechanisms towards Enterococcus faecalis and Candida albicans.

The essential goals of this present study are to elucidate the formation mechanism of ellagic acid rich-blackberry, BBE, (Rubus fruticosus L.) and raspberry, RBE, (Rubus idaeus L.) extracts directed silver nanoparticles and to investigate thier antimicrobial properties towards model dental pathogens E. faecalis and C. albicans compared to BBE, RBE, NaOCl, CHX and EDTA. Both %5 w/w of BBE and RBE reacted with 5 mM Ag + ions at room temperature (25 °C) under mild-stirring, the formation of BBE and RBE directed b@Ag NP and r@Ag NP was monitored over time by using an Uv-vis spectrophotometer. Both b@Ag and r@Ag NPs were also complementarily characterized with SEM and FT-IR. In terms of the antimicrobial studies, b@Ag NP, r@Ag NP, %5 BBE and RBE, 5 mM AgNO3, %5 NaOCl, %1,5 CHX and %15 EDTA were separately incubated with E. faecalis and C. albicans suspensions. The results were evaluated with student t-test using GraphPad Prism 8.0.1 statistical software (P < 0.05). While formation of b@Ag NP was confirmed with characteristic absorbance at ~435 nm in 20 min (min) of incubation, r@Ag NP did not give absorbance till 80 min owing to concentration of ellagic acid acted as a reducing and stabilizng agent for formation of the Ag NPs. Intrestingly, 50 ppm r@Ag NP inactivated ∼89% and ∼99% of E. faecalis and C. albicans cell, respectively, ∼25% and ∼40% cell inactivations for E. faecalis and C. albicans were observed respectively with 50 ppm b@Ag NP. We showed that 50 ppm r@Ag NP has effective antimicrobial property as much as mostly used %5 NaOCl and %1,5 CHX solutions.

Gallic acid nanoflower immobilized membrane with peroxidase-like activity for m-cresol detection.

We report fabrication of new generation nanoflowers (NFs) using gallic acid (GA) and copper (II) ions (Cu2+) acted as an organic and inorganic component, respectively with effective peroxidase mimic activities in solution and on filter membrane. Unlike the typical protein NFs synthesis mechanism, gallic acid NFs (GA-NFs) was formed via coordination reaction between carboxyl groups of GA and Cu2+. The different morphologies of the GA-NFs were acquired based upon whether the carboxyl groups in gallic acid are active or not. The peroxidase mimic activity of the GA-NFs relied on the Fenton reaction in the presence of hydrogen peroxide (H2O2) was tested towards m-cresol as a function of concentration of the GA-NFs, m-cresol, H2O2 and reaction time. Under the optimized conditions, the oxidative coupling of m-cresol with 4-aminoantipyrine (4-AAP) was catalyzed by the GA-NFs dispersed in solution and adsorbed on filter paper to form an antipyrine dye and it was visually and spectrophotometrically recorded. The m-cresol with range of 0.05-0.5 mM was detected in 10 min and 15 min by using the GA-NFs in solution and on filter paper, respectively. We demonstrated that the NFs can be produced from non-protein molecules and GA-NFs can be used as a promising nanocatalyst for a variety of applications.

Building block and rapid synthesis of catecholamines-inorganic nanoflowers with their peroxidase-mimicking and antimicrobial activities.

Protein incorporated flower-shaped hybrid nanostructures have received highly considerable attention due to their greatly enhanced catalytic activities and stabilities. Up to date, proteins, enzymes (mostly considered as proteins), and amino acids (as the building blocks of peptides and proteins) have been used as organic components of the hybrid nanoflowers. Herein, we present a rational strategy to rapidly form catecholamines (dopamine, epinephrine and norepinephrine)-copper ion (Cu2+) incorporated nanoflowers (cNFs) mostly in 3 hours and show their peroxidase-mimic catalytic, dye degradation and antimicrobial activities through Fenton-like reaction mechanism. We systematically studied effects of experimental parameters including catecholamine concentrations, reaction time and reaction pH values, on formation of the cNFs. We also explained that norepinephrine nanoflower (neNF) with its porous structure, high surface area, polar surface property behaves as an efficient Fenton agent by exhibiting highly much catalytic activities compared to dopamine nanoflower (dNF) and epinephrine nanoflower (epNF). We claim that the NFs formed using nonprotein molecules can be used in designing new generation nanobiocatalytics, antimicrobial agents, nanobiosensors and pharmaceutical products.

Preparation of natural indicator incorporated media and its logical use as a colorimetric biosensor for rapid and sensitive detection of Methicillin-resistant Staphylococcus aureus.

Herein, we report a rational design in preparation of natural indicator incorporated media used as a rapid, selective, sensitive and economic colorimetric biosensor for detection of Methicillin-resistant Staphylococcus aureus (MRSA). Anthocyanins obtained from red cabbage (Brassica oleracea) extract (RCE) are major components and acted as pH responsive indicators in the RCE media. The RCE media was tested for eight gram-positive, four gram-negative bacterial and one model fungal pathogens. We experimentally revealed how salt concentration and antibiotic (cefoxitin) in the RCE media influence the growth of pathogens and especially MRSA. Benefiting pH dependent color change function of anthocyanins is indispensable point of the RCE media in sensing of MRSA growth. The potential MRSA colorimetric sensing mechanism of anthocyanins relies on both protonation and decrease in electron density on structures of anthocyanins by acidic organic volatile compounds produced during growth of MRSA. The protonated anthocyanins with low electron density changed original purple color of the RCE media to pink color. We demonstrated that detection of MRSA was achieved by spectrophotometrically (one single cell) and visually with naked eyes (100 cells) in 2nd hrs and 6th hrs of incubation, respectively. We optimized concentrations of cefoxitin (from 1 µg/mL to 20 µg/mL) against MRSA and Methicillin-sensitive Staphylococcus aureus (MSSA) bacterial cell (3 McFarland) suspensions, then growth of MRSA was visually and clearly detected in the presence of 4 µg/mL cefoxitin between 90 min and 3 h. We persistently offer that the proposed RCE media can be a well alternative to currently used phenotypic methods in clinics owing to its much rapid, sensitive, selective and economic properties.

Preparation of nature inspired indicator based agar for detection and identification of MRSA and MRSE.

Natural indicator, red cabbage extract (RCE) incorporated agars were developed, for the first time, as colorimetric sensors for identification of MRSA and MRSE. These strains were differentiated in RCE media with addition of plasma due to coagulase positive property of MRSA, they were differentiated by manipulating NaCl and introducing gelatin in RCE agar. RCE agar was examined based on concentration of NaCl and MRSA concentrations and incubation time for detection of MRSA. RCE agar was prepared mixing 10g peptone, 1g beef extract, NaCl, 15 mg/mL agar and 25% RCE in distilled water and sterilized in autoclave at 121°C for 15 min. 4 µg/mL cefoxitin was added to mixture based on experiment. The color of RCE agar including 50 mg/mL NaCl was turned to pink dependent upon growth of MRSA, MRSE and MSSA, growth of E. coli was inhibited due to its salt intolerance property. Introducing 4 µg/mL cefoxitin, growth of MRSA was not observed. 1 CFU/mL, 10 CFU/mL, 100 CFU/mL and 1000 CFU/mL of MRSA inoculated on the RCE agar showed growth and led color change in 24 hrs. Additionally, slight pink spots on RCE agar and pale pink color on whole RCE agar were appeared in 8th hrs and 11th hrs of inoculation, respectively when 1000 CFU/mL of MRSA used. The RCE agar was successfully used for detection of MRSA and differentiation of them. Finally, the RCE agar can be implemented in clinics and may alleviate incubation time and cost compared to the chromogenic agars.

Synthesis of Long-Term Stable Gold Nanoparticles Benefiting from Red Raspberry (Rubus idaeus), Strawberry (Fragaria ananassa), and Blackberry (Rubus fruticosus) Extracts-Gold Ion Complexation and Investigation of Reaction Conditions.

We report synthesis of monodispersed, stable, and colloidal gold nanoparticles (Au NPs) using anthocyanin-riched red raspberry (Rubus idaeus), strawberry (Fragaria ananassa), and blackberry (Rubus fruticosus) extracts as functions of concentration of HAuCl4·3H2O and berries extract, reaction time, and reaction pH values (pHs) and demonstrate their unique stability in highly concentrated salt (sodium chloride, NaCl) solutions. The catecholamine group of anthocyanin molecules give preferential coordination reaction with gold ions (Au3+) for creating anthocyanin-Au3+ complexes, which may lead to initiation of nucleation for seed formation, and then, oxidation of catecholamine results in a flow of electrons from anthocyanins to Au seeds for anisotropic growth. Finally, the surface of the Au NPs is saturated with anthocyanins, and formation of monodispersed and stable Au NPs with narrow size distribution is completed. We also report the effects of some experimental parameters including concentrations of Au3+ ions and barrier extracts, reaction time, and pHs on formation of the Au NPs with rational explanations. The long-term colloidal stability of the Au NPs in the 400 mM NaCl solution was comparatively studied with commercial Au NPs (citrate capped). As results show that anthocyanin-riched berry extracts directed Au NPs we proposed here can be considered as promising and safe tools for biomedical applications owing to their highly much colloidal dispersibility and salt tolerance properties.

Formation of functional nanobiocatalysts with a novel and encouraging immobilization approach and their versatile bioanalytical applications.

The discovery of functional organic-inorganic hybrid nanoflowers (FNFs) consisting of proteins/enzymes as the organic components and Cu(ii) ion as the inorganic component has made an enormous impact on enzyme immobilization studies. The FNFs synthesized by an encouraging and novel approach not only showed high stabilities but also much enhanced catalytic activities as compared to free and conventionally immobilized enzymes. A recent development demonstrated that FNF formation has moved beyond the initial discovery in which enzymes and Cu2+ ions used as the organic and inorganic parts, respectively, are replaced with new organic (chitosan, amino acid and plant extracts) and inorganic (Cu2+ and Fe2+) materials. The new organic materials incorporated into FNFs act as Fenton-like agents and then show peroxidase-like activity owing to the metal ions and the porous structure of FNFs in the presence of hydrogen peroxide (H2O2). All FNFs have been widely utilized in many different scientific and industrial fields due to their greatly enhanced activities and stabilities. This review focuses primarily on the preparation, characterization, and bioanalytical applications of FNFs and explains the mechanisms of their formation and enhanced activities and stabilities.