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1.
Sci Rep ; 11(1): 15795, 2021 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-34349183

RESUMO

AgNPs are nanomaterials with many potential biomedical applications. In this study, the two novel yeast strains HX-YS and LPP-12Y capable of producing biological silver nanoparticles were isolated. Sequencing of ribosomal DNA-ITS fragments, as well as partial D1/D2 regions of 26S rDNA indicated that the strains are related to species from the genus Metschnikowia. The BioAgNPs produced by HX-YS and LPP-12Y at pH 5.0-6.0 and 26 °C ranged in size from 50 to 500 nm. The antibacterial activities of yeast BioAgNPs against five pathogenic bacteria were determined. The highest antibacterial effect was observed on P. aeruginosa, with additional obvious effects on E. coli ATCC8099 and S. aureus ATCC10231. Additionally, the BioAgNPs showed antiproliferative effects on lung cancer cell lines H1975 and A579, with low toxicity in Beas 2B normal lung cells. Therefore, the AgNPs biosynthesized by HX-YS and LPP-12Y may have potential applications in the treatment of bacterial infections and cancer.


Assuntos
Proliferação de Células/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Neoplasias Pulmonares/patologia , Nanopartículas Metálicas , Metschnikowia/metabolismo , Nanoestruturas , Pseudomonas aeruginosa/efeitos dos fármacos , Compostos de Prata/metabolismo , Compostos de Prata/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Linhagem Celular Tumoral , DNA Ribossômico , Humanos , Metschnikowia/genética , Metschnikowia/isolamento & purificação
2.
PLoS One ; 16(6): e0252734, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34115788

RESUMO

Silver diamine fluoride (SDF) is used in minimally invasive dentistry for arresting dental caries. However, discoloration of teeth is a significant side effect that has limited the use of SDF. Hence, the application of potassium iodide (KI) following SDF has been proposed to ameliorate the staining. Although antimicrobial activity is one of the major mechanisms of the caries-arresting effect of SDF, the antimicrobial potency of SDF/KI combination is unclear. Thus, the primary objective of this systematic review was to appraise the studies on the antimicrobial efficacy of SDF/KI combination on cariogenic microbes. The secondary objective was to summarize the evidence on the potential of KI in reducing the discoloration associated with the application of SDF. Electronic databases of Medline via PubMed, Cochrane Library, Web of Science, and EBSCO host were searched for English language manuscripts from January 2005 to 15th November 2020. The reference lists of these manuscripts were manually searched for additional studies. Twelve studies were included in the final analysis, seven of which have investigated the antimicrobial efficacy of SDF/KI, and the rest have examined the anti-staining potential of KI. The exploratory findings from the reviewed articles revealed the promising antimicrobial potential of SDF/KI on cariogenic microbes associated with dentine caries. There is, however, contradictory evidence on the effect of SDF/KI on tooth color. The reviewed in-vitro studies indicated significant effectiveness of KI in preventing staining. A clinical trial on primary dentition showed 25% reduction in the incidence of staining by SDF after applying KI, while a clinical study on root caries in adults showed no significant effect. Within the methodological limitations of this review, we conclude that for arresting dental caries, SDF could be combined with KI, as there may be a lower likelihood of staining. Further, well-designed clinical trials on the antimicrobial and anti-staining effect of SDF/KI are needed to obtain more robust evidence.


Assuntos
Biofilmes/efeitos dos fármacos , Placa Dentária/tratamento farmacológico , Iodeto de Potássio/uso terapêutico , Compostos de Amônio Quaternário/uso terapêutico , Compostos de Prata/uso terapêutico , Descoloração de Dente/tratamento farmacológico , Placa Dentária/microbiologia , Combinação de Medicamentos , Fluoretos Tópicos/administração & dosagem , Fluoretos Tópicos/farmacologia , Fluoretos Tópicos/uso terapêutico , Humanos , Microbiota , Iodeto de Potássio/administração & dosagem , Iodeto de Potássio/farmacologia , Compostos de Amônio Quaternário/administração & dosagem , Compostos de Amônio Quaternário/farmacologia , Compostos de Prata/administração & dosagem , Compostos de Prata/farmacologia , Descoloração de Dente/microbiologia
3.
ACS Appl Mater Interfaces ; 13(18): 21979-21993, 2021 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-33939418

RESUMO

Microbial contamination and the prevalence of resistant bacteria is considered a worldwide public health problem. Therefore, recently, great efforts have been made to develop photoresponsive platforms for the simultaneous photodynamic antibacterial (PDA) and photothermal antibacterial (PTA) therapy processes as mediated by specific light. However, owing to the absorption mismatches of the photothermal agents and photodynamic photosensitizers, it has been discovered that many synergistic photoresponsive antibacterial platforms cannot be excited by a single-wavelength light. In this study, silver bismuth sulfide quantum dots (AgBiS2 QDs) identified from the literature as a near-infrared light (NIR) that triggers bifunctional materials with simultaneous photodynamic and photothermal effects for photoresponsive bacterial killing were used. Specifically, AgBiS2 QDs were successfully synthesized via a bottom-up approach, using polyethylenimine (PEI) as an assistant molecule. With PEI wrapping, the attachment between the negatively charged membrane surfaces of the bacterial cells and AgBiS2 QDs was enhanced via the electrostatic interactions. The photodriven antibacterial activity of AgBiS2 QDs was then investigated against both S. aureus and E. coli. The results revealed a significant reduction in bacterial survival. The killing effect was found to be independent of the AgBiS2 QDs, and redox potentials controlled the photogenerated electrons that thermodynamically favored the formation of multiple reactive oxygen species (ROS). A possible phototriggered antibacterial mechanism was then proposed in which the AgBiS2 QDs are anchored first to the bacterial surface and then induce breaking on its outer membrane by high local heat and ROS under single 808 nm NIR laser illumination to finally induce bacterial death.


Assuntos
Bismuto/química , Pontos Quânticos , Compostos de Prata/química , Sulfetos/química , Antibacterianos/farmacologia , Bismuto/farmacologia , Escherichia coli/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Compostos de Prata/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Sulfetos/farmacologia
4.
Int J Biol Macromol ; 183: 35-44, 2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-33901555

RESUMO

The study reports designing of a new, low-cost and environmentally friendly colorimetric and fluorometric sensor by using cellulose-based materials for detection and determination of Fe(III). To make powder cellulose (Cel) and filter paper (PCel) fluorescent, they were modified with hexamethylene diisocyanate (HMDI) and 4-sulfo-1,8-naphthalimide (Nap). Fluorescent Cel-Nap and PCel-Nap materials were used for spectroscopic detection of Fe(III). The working range of the designed sensor was determined as 1.0 × 10-5-4.5 × 10-5 M with a low limit of detection (LOD) (7.51 µM). Antimicrobial properties of cel-based compounds and Ag(I)-containing compounds were tested against five bacteria; Bacillus cereus, Streptococcus mutans, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and two fungi; Candida albicans and Candida tropicalis. The materials exhibited antimicrobial effects and their antifungal properties were more effective than their antibacterial properties.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Técnicas Biossensoriais , Celulose/farmacologia , Ferro/análise , Compostos de Prata/farmacologia , Antibacterianos/química , Antifúngicos/química , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Candida/efeitos dos fármacos , Candida/crescimento & desenvolvimento , Celulose/química , Fluorometria , Isocianatos/química , Naftalimidas/química , Compostos de Prata/química
5.
J Wound Care ; 30(3): 238-247, 2021 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-33729837

RESUMO

OBJECTIVE: Silver has become a global treatment option with the US Food and Drug Administration providing marketing clearance for many silver-impregnated wound dressings and topical agents. However, the increased use of silver-based products across medical disciplines has raised questions concerning the development of acute silver resistance. In this study, the efficacy of previously identified silver-resistant clinical bacteria (Klebsiella pneumoniae and Enterobacter cloacae) against a variety of commercially available silver-based wound dressings was further investigated. METHOD: To further explore the clinical significance of these isolates, multiple time-course and repeat-challenge assays were conducted with nine dressings using a panel of silver-resistant and silver-sensitive microorganisms. Silver-impregnated dressings were ranked by silver species, quantity of silver and overall efficacy. RESULTS: Both silver-resistant strains were largely unaffected and exhibited phenotypic resistance even when exposed to the high silver concentrations found in commercially available wound dressings. In stark contrast, the majority of the dressings were able to maintain a high degree of efficacy over the course of 72 hours and during repeated bacterial challenges against silver-sensitive microorganisms. CONCLUSION: Our findings provide additional evidence that clinically significant silver-resistance has emerged in the clinical setting. Such resistant microbes are capable of sustained silver resistance against a wide variety of silver adjuvants. These findings suggest that the further development and dissemination of these resistance mechanisms could significantly impact current practices in wound healing.


Assuntos
Anti-Infecciosos Locais/farmacologia , Enterobacter cloacae/isolamento & purificação , Klebsiella pneumoniae/isolamento & purificação , Compostos de Prata/farmacologia , Prata/farmacologia , Cicatrização , Infecção dos Ferimentos/tratamento farmacológico , Gestão de Antimicrobianos , Bandagens , Queimaduras , Humanos , Testes de Sensibilidade Microbiana , Infecção dos Ferimentos/microbiologia
6.
Sci Rep ; 11(1): 6083, 2021 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-33727650

RESUMO

This in vitro study evaluated the protective effect of titanium tetrafluoride (TiF4) varnish and silver diamine fluoride (SDF) solution on the radiation-induced dentin caries. Bovine root dentin samples were irradiated (70 Gy) and treated as follows: (6 h): 4% TiF4 varnish; 5.42% NaF varnish; 30% SDF solution; placebo varnish; or untreated (negative control). Microcosm biofilm was produced from human dental biofilm (from patients with head-neck cancer) mixed with McBain saliva for the first 8 h. After 16 h and from day 2 to day 5, McBain saliva (0.2% sucrose) was replaced daily (37 °C, 5% CO2) (biological triplicate). Demineralization was quantified by transverse microradiography (TMR), while biofilm was analyzed by using viability, colony-forming units (CFU) counting and lactic acid production assays. The data were statistically analyzed by ANOVA (p < 0.05). TiF4 and SDF were able to reduce mineral loss compared to placebo and the negative control. TiF4 and SDF significantly reduced the biofilm viability compared to negative control. TiF4 significantly reduced the CFU count of total microorganism, while only SDF affected total streptococci and mutans streptococci counts. The varnishes induced a reduction in lactic acid production compared to the negative control. TiF4 and SDF may be good alternatives to control the development of radiation-induced dentin caries.


Assuntos
Cárie Dentária , Dentina , Compostos de Amônio Quaternário/farmacologia , Lesões Experimentais por Radiação , Protetores contra Radiação/farmacologia , Compostos de Prata/farmacologia , Titânio/farmacologia , Raios X/efeitos adversos , Animais , Bovinos , Cárie Dentária/metabolismo , Cárie Dentária/patologia , Cárie Dentária/prevenção & controle , Dentina/metabolismo , Dentina/patologia , Fluoretos Tópicos/farmacologia , Lesões Experimentais por Radiação/metabolismo , Lesões Experimentais por Radiação/patologia , Lesões Experimentais por Radiação/prevenção & controle
7.
Dent Mater J ; 40(4): 1041-1048, 2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-33775984

RESUMO

This study evaluated the ability of different types of silver diammine fluoride (SDF) to inhibit dentin demineralization using micro-focused X-ray computed-tomography (µCT). Dentin specimens were divided into five groups (n=10); no-treatment (control), 3.8% SDF (RC), 38% SDF, 38% SDF with potassium iodide (SDF/KI), and potassium fluoride (KF). The treated-dentin surfaces were subjected to demineralization for 7-days and assessed using µCT to determine mineral loss (ML) values. Specimens were also analyzed with scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The ML values of the SDF and KF groups were significantly lower than those of the RC and SDF/KI groups. EDS detected fluoride ions in the SDF and KF groups but not in the RC and SDF/KI groups. It was concluded that 38% SDF demonstrated a high ability to inhibit dentin demineralization while additional application of KI may diminish the inhibitory effect of SDF. The amount of dentin demineralization with SDF treatments was material dependent.


Assuntos
Fluoretos , Desmineralização do Dente , Amônia , Dentina , Fluoretos/farmacologia , Fluoretos Tópicos/farmacologia , Humanos , Compostos de Prata/farmacologia , Desmineralização do Dente/prevenção & controle , Microtomografia por Raio-X
8.
Dent Mater J ; 40(4): 911-917, 2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-33731542

RESUMO

Effects of silver diamine fluoride preparations (SDFs) on cariogenic biofilm formation on root dentin (RD) were investigated. Streptococcus mutans (S. mutans) biofilms were formed on bovine RD blocks coated with one of three the SDFs (38%-SDF, 3.8%-SDF and 35%-SDF+potassium-iodide; SDF+KI) and a non-coated Control which were quantified (spectrometric-measurement) and thickness measured (optical coherence tomography) after 20 h. Bacterial viability test (BacLight) and biofilm-morphometry (SEM) of 2 h biofilms were also performed. The amounts of biofilms (bacteria and water insoluble glucan) and the thickness of biofilm were minimum on 38%-SDF specimen; 3.8%-SDF and SDF+KI had significantly more than that, but had significantly less than Control (p<0.05). Most S. mutans cells found dead and morphology damaged by 38%-SDF. Some dead bacteria and remarkably damaged biofilms were observed in case of 3.8%-SDF and SDF+KI. Inhibition potential of 3.8%-SDF and SDF+KI on S. mutans biofilm formation is almost similar, although not equivalent to 38%-SDF.


Assuntos
Cárie Dentária , Streptococcus mutans , Animais , Biofilmes , Bovinos , Fluoretos Tópicos/farmacologia , Compostos de Amônio Quaternário , Compostos de Prata/farmacologia
9.
Biomed Pharmacother ; 137: 111294, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33571836

RESUMO

The drugs used to treat cutaneous leishmaniasis (CL) cannot effectively penetrate lesions. Nanogold and nanosilver have been used for treating or enhancing drug delivery in CL. The present study used Commiphora molmol (myrrh) to synthesize silver nanoparticles (MSNPs). The MSNPs were characterized using transmission electron microscopy and energy-dispersive spectroscopy. In addition, antiparasitic effect of myrrh silver nanoparticles (MSNPs) was assessed on Leishmania major both in vitro and in vivo. Five concentrations of MSNPs (10, 50, 80, 100, and 150 µl/100 µL) were used to study their effect on L. major cultures in vitro, and MSNPs were also applied topically to subcutaneous lesions in mice in vivo. The results showed that the MSNPs were 49.09 nm in size. MSNPs, showed a marked and significant (p ≤ 0.05) growth inhibition of L. major promastigotes which was concentration dependent. Overall, the higher concentrations (100, 150 µl/100 µL had a significantly greater inhibitory effect for the MSNPs in comparison to the chemical nanoparticles (CNPs) and pentostam at the same concentrations. Lesions healed completely in 21 d after MSNP treatment in vivo, while pentostam, a commercial drug, and CNPs showed a moderate healing effect on the lesions. Thus, MSNPs were more effective than pentostam and CNPs both in the in vivo and in vitro studies. MSNPs can therefore be promising candidates for various nanomedicine applications.


Assuntos
Commiphora/química , Excipientes/química , Química Verde , Leishmania major/efeitos dos fármacos , Leishmaniose Cutânea/tratamento farmacológico , Nanopartículas Metálicas , Substâncias Redutoras/química , Compostos de Prata/farmacologia , Tripanossomicidas/farmacologia , Animais , Modelos Animais de Doenças , Composição de Medicamentos , Leishmania major/crescimento & desenvolvimento , Leishmania major/ultraestrutura , Leishmaniose Cutânea/parasitologia , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Parasitária , Compostos de Prata/síntese química , Tripanossomicidas/síntese química
10.
Yakugaku Zasshi ; 141(1): 135-142, 2021.
Artigo em Japonês | MEDLINE | ID: mdl-33390440

RESUMO

Environmental microorganisms can cause several infections in humans, especially in compromised hosts. Since there are many compromised hosts in a hospital setting, it is important to control environmental pathogens in such scenarios. To disinfect the environment, photocatalysts that produce reactive oxygen in response to light have attracted attention. In the present study, the effects of a visible-light-driven antimicrobial photocatalyst, silver (I) iodide and benzalkonium complex, on bacteria, viruses, and fungi were evaluated in vitro. In addition, uncoated panels and panels coated with the photocatalyst were set up at 11 points in a university campus for 6 months, and the adherent bacteria and fungi were measured. Bacteria, bacterial spores, viruses, and fungi were completely inactivated within 45 min on the photocatalyst-coated surface exposed to approximately 700-lux fluorescent light. In the university setting, there were fewer viable adherent bacteria and fungi on the coated plates. Our findings indicate that the silver (I) iodide and benzalkonium complex photocatalyst can decrease environmental bacteria in vitro and in actual environmental settings, and thus highlight its potential in controlling and disinfecting environmental pathogens.


Assuntos
Compostos de Benzalcônio , Desinfecção/métodos , Microbiologia Ambiental , Fluorescência , Controle de Infecções/métodos , Iodetos , Luz , Compostos de Prata , Bactérias/efeitos dos fármacos , Compostos de Benzalcônio/farmacologia , Fungos/efeitos dos fármacos , Iodetos/farmacologia , Espécies Reativas de Oxigênio/farmacologia , Compostos de Prata/farmacologia , Inativação de Vírus/efeitos dos fármacos
11.
Sci Rep ; 11(1): 84, 2021 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-33420131

RESUMO

The use of cellulosic polymers as efficient reducing, coating agents, and stabilizers in the formulation of silver nanoparticles (AgNPs) with antioxidant and antibacterial activity was investigated. AgNPs were synthesized using different cellulosic polymers, polyethylene glycol, and without polymers using tri-sodium citrate, for comparison. The yield, morphology, size, charge, in vitro release of silver ion, and physical stability of the resulting AgNPs were evaluated. Their antioxidant activity was measured as a scavenging percentage compared with ascorbic acid, while their antibacterial activity was evaluated against different strains of bacteria. The amount of AgNPs inside bacterial cells was quantified using an ICP-OES spectrometer, and morphological examination of the bacteria was performed after AgNPs internalization. Cellulosic polymers generated physically stable AgNPs without any aggregation, which remained physically stable for 3 months at 25.0 ± 0.5 and 4.0 ± 0.5 °C. AgNPs formulated using ethylcellulose (EC) and hydroxypropyl methylcellulose (HPMC) had significant (p ≤ 0.05; ANOVA/Tukey) antibacterial activities and lower values of MIC compared to methylcellulose (MC), PEG, and AgNPs without a polymeric stabilizer. Significantly (p ≤ 0.05; ANOVA/Tukey) more AgNPs-EC and AgNPs-HPMC were internalized in Escherichia coli cells compared to other formulations. Thus, cellulosic polymers show promise as polymers for the formulation of AgNPs with antioxidant and antibacterial activities.


Assuntos
Antibacterianos/química , Antioxidantes/química , Nanopartículas Metálicas/química , Compostos de Prata/química , Antibacterianos/farmacologia , Antioxidantes/farmacologia , Nanopartículas Metálicas/ultraestrutura , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Espectroscopia Fotoeletrônica , Polímeros , Compostos de Prata/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier
12.
Arch Oral Biol ; 121: 104950, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33161341

RESUMO

OBJECTIVES: This study investigated the ability of SDF, and its individual components, silver (Ag+) and fluoride (F-) ions, in preventing enamel demineralization under pH-cycling conditions in the presence or absence of twice-daily fluoride application. DESIGN: Polished human enamel specimens were assigned to five treatment groups (n = 36 per group): SDF (38 %); SDF followed by application of a saturated solution of potassium iodide (SDF + KI); silver nitrate (AgNO3; silver control, 253,900 ppm Ag); potassium fluoride (KF; fluoride control, 44,800 ppm F); deionized water. Treatments were applied once. Specimens in each treatment group were divided into two subgroups (n = 18). During the subsequent 7-day pH-cycling phase, specimens were treated twice daily with either 275 ppm fluoride as sodium fluoride or deionized water, immediately before and after a 3-h cariogenic challenge with exposure to artificial saliva at all other times. Changes in color, Vickers surface microhardness (SMH), transverse microradiography (TMR) was calculated. Data were analyzed using two-way ANOVA. RESULTS: In both models, SDF, SDF + KI and KF were superior in inhibiting demineralization compared to AgNO3 and deionized water (p < 0.0001). There was no statistically significant difference between SDF, SDF + KI and KF with twice daily fluoride treatments (p > 0.8). However, KF was more effective in preventing demineralization than SDF and SDF + KI in the absence of fluoride treatments (p = 0.0002). KI did not affect the ability of SDF to prevent demineralization (p > 0.4). CONCLUSION: SDF and SDF + KI appears to be an effective option in preventing primary coronal caries.


Assuntos
Cariostáticos/farmacologia , Cárie Dentária , Fluoretos Tópicos , Compostos de Amônio Quaternário/farmacologia , Compostos de Prata/farmacologia , Cárie Dentária/prevenção & controle , Fluoretos Tópicos/farmacologia , Humanos , Concentração de Íons de Hidrogênio , Técnicas In Vitro , Fluoreto de Sódio/farmacologia
13.
Carbohydr Polym ; 254: 117416, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33357900

RESUMO

Chitosan was modified by substituting alkynyl silver on chitosan (Ag-CS) through a two-step chemical modification to form a novel antimicrobial coating material. The physicochemical property, antimicrobial activity, cytotoxicity, and potential food applications of Ag-CS were systematically investigated. The Ag-CS presented a smooth sheet structure, and demonstrated stronger antimicrobial effects than either silver acetate (AgOAc) or silver nitrate (AgNO3) against both Gram positive and Gram negative bacteria strains. Ag-CS also demonstrated a controlled release of Ag for over 5 days, whereas AgOAc or AgNO3 infused chitosan released over 90 % Ag within 4 h. Ag-CS coating on shrimps significantly extended their shelf-life. Overall, our results revealed that the newly developed Ag-CS antimicrobial coating material possesses strong antimicrobial efficacies with a sustained Ag release property, and its ability to slow down the spoilage rate of shrimps indicates its potential in the improvement of food quality and shelf life.


Assuntos
Acetatos/química , Alcinos/química , Antibacterianos/química , Quitosana/química , Qualidade dos Alimentos , Armazenamento de Alimentos/métodos , Compostos de Prata/química , Acetatos/farmacologia , Alcinos/farmacologia , Animais , Antibacterianos/farmacologia , Quitosana/farmacologia , Relação Dose-Resposta a Droga , Escherichia coli/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Nitrogênio/análise , Penaeidae/efeitos dos fármacos , Penaeidae/microbiologia , Compostos de Prata/farmacologia , Nitrato de Prata/química , Nitrato de Prata/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Viscosidade
14.
PLoS One ; 15(11): e0241519, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33141868

RESUMO

Silver diamine fluoride (SDF) is commonly used to arrest caries lesions, especially in early childhood caries. Recently, it was suggested that SDF can be combined with potassium iodide (KI) to minimize the discoloration of demineralized dentine associated with SDF application. However, the antibacterial efficacy of SDF alone or combined with KI on in-situ biofilm is unknown. Hence, we compared the anti-plaque biofilm efficacy of two different commercially available SDF solutions, with or without KI, using an in-situ biofilm, analysed using viability real-time PCR with propidium monoazide (PMA). Appliance-borne in-situ biofilm samples (n = 90) were grown for a period of 6 h in five healthy subjects who repeated the experiment on three separate occasions, using a validated, novel, intraoral device. The relative anti-biofilm efficacy of two SDF formulations; 38.0% Topamine (SDFT) and 31.3%, Riva Star (SDFR), KI alone, and KI in combination with SDFR (SDFR+KI) was compared. The experiments were performed by applying an optimized volume of the agents onto the biofilm for 1min, mimicking the standard clinical procedure. Afterwards the viability of the residual biofilm bacteria was quantified using viability real-time PCR with PMA, then the percentage of viable from total bacteria was calculated. Both SDF formulations (SDFT and SDFR) exhibited potent antibacterial activities against the in-situ biofilm; however, there was non-significant difference in their efficacy. KI alone did not demonstrate any antibacterial effect, and there was non-significant difference in the antibacterial efficacy of SDF alone compared to SDF with KI, (SDFT v SDFR/KI). Thus, we conclude that the antibacterial efficacy of SDF against plaque biofilms is not modulated by KI supplements. Viability real-time PCR with PMA was successfully used to analyze the viability of naturally grown oral biofilm; thus, the same method can be used to test the antimicrobial effect of other agents on oral biofilms in future research.


Assuntos
Antibacterianos/farmacologia , Azidas/farmacologia , Biofilmes/classificação , Iodeto de Potássio/farmacologia , Propídio/análogos & derivados , Compostos de Amônio Quaternário/farmacologia , Reação em Cadeia da Polimerase em Tempo Real , Compostos de Prata/farmacologia , Adulto , Biofilmes/efeitos dos fármacos , Calibragem , Feminino , Fluoretos Tópicos/farmacologia , Humanos , Masculino , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Propídio/farmacologia
15.
Sci Rep ; 10(1): 19615, 2020 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-33184403

RESUMO

The present study reports the synergistic antibacterial activity of biosynthesized silver nanoparticles (AgNPs) with the aid of a combination of chitosan and seaweed-derived polyphenols as a green synthetic route. Under optimum synthesis conditions, the rapid color change from yellowish to dark brown and UV-visible absorption peak at 425 confirmed the initial formation of AgNPs. DLS, TEM, XRD, and EDX analyses revealed the spherical shape of pure biogenic AgNPs with a mean diameter size of 12 nm ± 1.5 nm, and a face-centered cubic crystal structure, respectively. FTIR and TGA results indicated the significant contribution of chitosan and polyphenol components into silver ions bioreduction and thermal stability of freshly formed AgNPs. Long-term colloidal stability of AgNPs was obtained after 6-month storage at room temperature. The bio-prepared AgNPs possessed a negative surface charge with a zeta potential value of - 27 mV. In contrast to naked chemical silver nanoparticles, the green Ag nanosamples demonstrated the distinct synergistic antibacterial in vitro toward all selected human pathogens presumably due to the presence of high content of biomolecules on their surface. The results show that synergy between chitosan and polyphenol results in the enhancement of bactericidal properties of biogenic AgNPs. We also highlighted the underlying mechanism involved in AgNPs formation based on nucleophile-electrophile interaction.


Assuntos
Bacillus cereus/efeitos dos fármacos , Quitosana/farmacologia , Química Verde/métodos , Nanopartículas , Polifenóis/farmacologia , Proteus/efeitos dos fármacos , Salmonella/efeitos dos fármacos , Compostos de Prata/farmacologia , Resistência Microbiana a Medicamentos , Estabilidade de Medicamentos , Armazenamento de Medicamentos , Sinergismo Farmacológico , Tamanho da Partícula , Compostos de Prata/química , Temperatura , Fatores de Tempo , Difração de Raios X
16.
Sci Rep ; 10(1): 19884, 2020 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-33199833

RESUMO

This study evaluated the effect of mechanical abrasion on the surface integrity, color change (ΔE) and antibacterial properties of demineralized and sound dentin surfaces treated with silver-diammine-fluoride (SDF). The dentin specimens were divided into two groups: sound and demineralized dentin, then divided into three sub-groups, control (no-treatment), SDF, and SDF + potassium-iodide (KI). Each sub-group was further divided into two groups, one exposed to mechanical brushing and the other without brushing. Specimens were analyzed for the ΔE, surface roughness/surface loss and antibacterial properties (CFU, optical density and fluorescent microscope). Repeated Measures ANOVA was used for statistical analysis of color change while one-way ANOVA was used for CFU analysis. SDF and SDI + KI groups showed significant reduction in ΔE with brushing in the sound dentin group unlike the demineralized group. The surface roughness values were higher for both SDF and SDF + KI groups but roughness values significantly decreased after brushing. Both SDF and SDF + KI groups revealed significantly less surface loss than control. The SDF group showed high anti-bacterial effect after brushing, unlike SDF + KI group. So, we concluded that mechanical brushing improved the esthetic outcome. While, SDF and SDF + KI could protect the dentin surface integrity. SDF-treated dentin possesses an antibacterial property even after mechanical brushing.


Assuntos
Antibacterianos/farmacologia , Dentina/efeitos dos fármacos , Iodeto de Potássio/farmacologia , Compostos de Amônio Quaternário/farmacologia , Compostos de Prata/farmacologia , Animais , Bovinos , Fluoretos Tópicos/farmacologia , Teste de Materiais , Fenômenos Mecânicos , Microscopia de Fluorescência , Propriedades de Superfície
17.
IET Nanobiotechnol ; 14(8): 707-713, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33108328

RESUMO

In this study, the extract of two strains of cyanobacteria was used for the synthesis of silver nanoparticles (NPs). UV-vis spectroscopy, X-ray diffraction, dynamic light scattering and field emission scanning electron microscopy (FESEM) analyses were carried out to characterise the NPs. The antioxidant activity and heavy metal detection properties were investigated; moreover, their minimum inhibitory concentration and minimum bactericidal concentration against the multi-drug resistant bacteria were determined. The most abundant materials in these extracts were carbohydrates, so the biosynthesis of NPs using exopolysaccharide (EPS) was also investigated. The surface plasmon resonance of NPs had a peak at 435 nm and EPS NPs at 350-450 nm. The NPs produced by Nostoc sp. IBRC-M5064 extract revealed the face-centred cubic (fcc) structure of AgCl, while NPs of N. pruniforme showed the fcc crystalline structure of Ag3PO4 and AgCl. The FESEM showed the spherical shape of these NPs. The AgCl/Ag3PO4 colloid, in comparison with AgCl, showed better antioxidant activity and antibacterial effect. The heavy metal detection analysis of NPs revealed that the NPs of both stains involved in Hg (NO3)2 detection.


Assuntos
Antibacterianos/farmacologia , Cianobactérias/efeitos dos fármacos , Nanopartículas Metálicas/administração & dosagem , Nanopartículas Metálicas/química , Fosfatos/química , Compostos de Prata/química , Antibacterianos/química , Antioxidantes/química , Antioxidantes/farmacologia , Colorimetria , Cianobactérias/crescimento & desenvolvimento , Química Verde , Testes de Sensibilidade Microbiana , Fosfatos/farmacologia , Compostos de Prata/farmacologia
18.
PLoS One ; 15(9): e0238590, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32941456

RESUMO

The aim of this study was to evaluate the effect of silver diamine fluoride and grape seed extract on the microstructure and mechanical properties of carious dentin following exposure to acidic challenge. Ninety-eight molars with occlusal caries were used. In the control group the specimens were kept in distilled water. In the GSE group, the specimens were immersed in 6.5% grape seed extract solution for 30 minutes. In the SDF group, the specimens were immersed in 30% SDF solution for 4 minutes. In the GSE+SDF group, the specimens were immersed in 6.5% grape seed extract solution for 30 minutes and then exposed to 30% SDF solution for 4 minutes. All the groups underwent pH cycling model for 8 days. Microhardness measurements were taken at the baseline before surface treatments and after pH cycling. Elastic modulus was measured, after pH cycling. In the control group, the final hardness was significantly lower than the initial hardness (P = 0.001). In the SDF group, the final hardness was significantly higher than the initial hardness (P < 0.001). There was no significant difference between the initial and final hardness values in the GSE and GSE + SDF groups (p = 0.92, p = 0.07). The H1-H0 in the SDF group was significantly higher than the other groups (P<0.05). Moreover, elastic modulus of the experimental groups except GSE+SDF group was significantly higher than control. The highest mean elastic modulus was detected in the SDF group (P<0.001). The use of SDF and GSE prior to the acid challenge improved mechanical properties. Microstructural investigation, using scanning electron microscope showed dentin structure protection against acid challenges with SDF treatment and collagen matrix stabilization with GSE treatment. However combined use of these agents was not beneficious.


Assuntos
Ácidos/efeitos adversos , Dentina/efeitos dos fármacos , Extrato de Sementes de Uva/farmacologia , Proantocianidinas/farmacologia , Substâncias Protetoras/farmacologia , Compostos de Amônio Quaternário/farmacologia , Compostos de Prata/farmacologia , Fenômenos Biomecânicos/efeitos dos fármacos , Dentina/ultraestrutura , Módulo de Elasticidade/efeitos dos fármacos , Fluoretos Tópicos/farmacologia , Humanos
19.
Sci Rep ; 10(1): 13309, 2020 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-32764617

RESUMO

Research efforts towards developing near-infrared (NIR) therapeutics to activate the proliferation of human keratinocytes and collagen synthesis in the skin microenvironment have been minimal, and the subject has not been fully explored. Herein, we describe the novel synthesis Ag2S nanoparticles (NPs) by using a sonochemical method and reveal the effects of NIR irradiation on the enhancement of the production of collagen through NIR-emitting Ag2S NPs. We also synthesized Li-doped Ag2S NPs that exhibited significantly increased emission intensity because of their enhanced absorption ability in the UV-NIR region. Both Ag2S and Li-doped Ag2S NPs activated the proliferation of HaCaT (human keratinocyte) and HDF (human dermal fibroblast) cells with no effect on cell morphology. While Ag2S NPs upregulated TIMP1 by only twofold in HaCaT cells and TGF-ß1 by only fourfold in HDF cells, Li-doped Ag2S NPs upregulated TGF-ß1 by tenfold, TIMP1 by 26-fold, and COL1A1 by 18-fold in HaCaT cells and upregulated TGF-ß1 by fivefold and COL1A1 by fourfold in HDF cells. Furthermore, Ag2S NPs activated TGF-ß1 signaling by increasing the phosphorylation of Smad2 and Smad3. The degree of activation was notably higher in cells treated with Li-doped Ag2S NPs, mainly caused by the higher PL intensity from Li-doped Ag2S NPs. Ag2S NPs NIR activates cell proliferation and collagen synthesis in skin keratinocytes and HDF cells, which can be applied to clinical light therapy and the development of anti-wrinkle agents for cosmetics.


Assuntos
Colágeno/biossíntese , Raios Infravermelhos , Nanopartículas/química , Transdução de Sinais/efeitos dos fármacos , Compostos de Prata/química , Compostos de Prata/farmacologia , Fator de Crescimento Transformador beta/metabolismo , Humanos , Queratinócitos/citologia , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo
20.
ACS Appl Mater Interfaces ; 12(36): 40052-40066, 2020 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-32806885

RESUMO

Ameliorated therapy based on the tumor microenvironment is becoming increasingly popular, yet only a few methods have achieved wide recognition. Herein, targeting multifunctional hydrophilic nanomicelles, AgBiS2@DSPE-PEG2000-FA (ABS-FA), were obtained and employed for tumor treatment. In a cascade amplification mode, ABS-FA exhibited favorable properties of actively enhancing computed tomography/infrared (CT/IR) imaging and gently relieving ambient oxygen concentration by cooperative photothermal and sonodynamic therapy. Compared with traditional Bi2S3 nanoparticles, the CT imaging capability of the probe was augmented (43.21%), and the photothermal conversion efficiency was increased (33.1%). Furthermore, remarkable ultrasonic dynamic features of ABS-FA were observed, with increased generation of reactive oxygen species (24.3%) being obtained compared to Ce6, a commonly used sonosensitizer. Furthermore, ABS-FA exhibited obvious inhibitory effects on HeLa cell migration at 6 µg/mL, which to some extent, demonstrated its suppressive effect on tumor growth. A lower dose, laser and ultrasonic power, and shorter processing time endowed ABS-FA with excellent photothermal and sonodynamic effects. By mild cascade mode, the hypoxic condition of the tumor site was largely improved, and a suitable oxygen-rich environment was provided, thereby endowing ABS-FA with a superior synergistically enhanced treatment effect compared with the single-mode approach, which ultimately realized the purpose of "one injection, multiple treatment". Moreover, our data showed that ABS-FA was given with a biological safety profile while harnessing in vivo. Taken together, as a synergistically enhanced medical diagnosis and treatment method, the one-for-all nanoplatform will pave a new avenue for further clinical applications.


Assuntos
Antineoplásicos/farmacologia , Ácido Fólico/farmacologia , Neoplasias Experimentais/terapia , Terapia Fototérmica , Compostos de Prata/farmacologia , Sulfetos/farmacologia , Terapia por Ultrassom , Animais , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Ácido Fólico/química , Células HeLa , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias Experimentais/patologia , Tamanho da Partícula , Compostos de Prata/química , Sulfetos/química , Propriedades de Superfície
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