scholarly journals Surface Characteristics of Orthodontic Materials and Their Effects on Adhesion of Mutans streptococci

2009 ◽  
Vol 79 (2) ◽  
pp. 353-360 ◽  
Author(s):  
Seung-Pyo Lee ◽  
Shin-Jae Lee ◽  
Bum-Soon Lim ◽  
Sug-Joon Ahn
Keyword(s):  
Laser Scanning ◽  
Sessile Drop ◽  
Raw Materials ◽  
Surface Characteristics ◽  
Mutans Streptococci ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Orthodontic Adhesives ◽  
Whole Saliva ◽  
Orthodontic Materials

AbstractObjective: To test the hypothesis that there are no significant differences in the adhesion of mutans streptococci (MS) to various orthodontic materials based on their surface characteristics.Materials and Methods: Surface roughness (SR) and surface free energy (SFE) characteristics were investigated for nine different orthodontic materials (four orthodontic adhesives, three bracket raw materials, hydroxyapatite blocks, and bovine incisors) using confocal laser scanning microscopy and sessile drop method. Each material, except the bovine incisors, was incubated with whole saliva or phosphate-buffered saline for 2 hours. Adhesion assays were performed by incubating tritium-labeled MS with each material for 3 or 6 hours.Results: Orthodontic adhesives had higher SFE characteristics and lower SR than bracket materials. Orthodontic adhesives showed a higher MS retaining capacity than bracket materials, and MS adhesion to resin-modified glass ionomer and hydroxyapatite was highest. Extended incubation time increased MS adhesion, while saliva coating did not significantly influence MS adhesion. SFE, specifically its dispersive and polar components, was positively correlated with MS adhesion, irrespective of saliva coating.Conclusions: The hypothesis is rejected. This study suggests that SFE characteristics play an important role in the initial MS adhesion to orthodontic materials.

scholarly journals Effects of Antifungal Carriers Based on Chitosan-Coated Iron Oxide Nanoparticles on Microcosm Biofilms

Antibiotics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 588
Author(s):  
Anne Caroline Morais Caldeirão ◽  
Heitor Ceolin Araujo ◽  
Camila Miranda Tomasella ◽  
Caio Sampaio ◽  
Marcelo José dos Santos Oliveira ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Lactic Acid ◽  
Iron Oxide ◽  
Iron Oxide Nanoparticles ◽  
Laser Scanning ◽  
Fungal Infections ◽  
Mutans Streptococci ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Oxide Nanoparticles

Resistance of Candida species to conventional therapies has motivated the development of antifungal nanocarriers based on iron oxide nanoparticles (IONPs) coated with chitosan (CS). This study evaluates the effects of IONPs-CS as carriers of miconazole (MCZ) or fluconazole (FLZ) on microcosm biofilms. Pooled saliva from two healthy volunteers supplemented with C. albicans and C. glabrata was the inoculum for biofilm formation. Biofilms were formed for 96 h on coverslips using the Amsterdam Active Attachment model, followed by 24 h treatment with nanocarriers containing different concentrations of each antifungal (78 and 156 µg/mL). MCZ or FLZ (156 µg/mL), and untreated biofilms were considered as controls. Anti-biofilm effects were evaluated by enumeration of colony-forming units (CFUs), composition of the extracellular matrix, lactic acid production, and structure and live/dead biofilm cells (confocal laser scanning microscopy-CLSM). Data were analyzed by one-way ANOVA and Fisher LSD’s test (α = 0.05). IONPs-CS carrying MCZ or FLZ were the most effective treatments in reducing CFUs compared to either an antifungal agent alone for C. albicans and MCZ for C. glabrata. Significant reductions in mutans streptococci and Lactobacillus spp. were shown, though mainly for the MCZ nanocarrier. Antifungals and their nanocarriers also showed significantly higher proportions of dead cells compared to untreated biofilm by CLSM (p < 0.001), and promoted significant reductions in lactic acid, while simultaneously showing increases in some components of the extracellular matrix. These findings reinforce the use of nanocarriers as effective alternatives to fight oral fungal infections.

Doxorubicin and siRNA Co-Delivery System Based on Carbon Dots Inhibits Chemoresistance of Lung Cancer

2021 ◽  
Author(s):  
Hui Luo ◽  
Kexin Tang ◽  
Kaichen Huang ◽  
Xi Lin ◽  
Chaoming Mei ◽  
...  
Keyword(s):  
Delivery System ◽  
Carbon Dots ◽  
Laser Scanning ◽  
Raw Materials ◽  
Metastatic Potential ◽  
Laser Scanning Microscopy ◽  
Migration And Invasion ◽  
Confocal Laser ◽  
Clinical Practices ◽  
Anti Cancer

Abstract BackgroundThe resistance to the anti-cancer agent limits the chemotherapy effect in the cancer therapy. Tumor easily develops resistance to anti-cancer drugs leading to decreased therapy efficiency of chemotherapies. Targeting signaling molecules related with chemoresistance through strategy of co-delivery siRNA and chemotherapeutics may overcome the multidrug resistance to chemotherapy. A co-delivery nanosystem that could carry siRNA and DOX simultaneously has been studied in this work. ResultsThe co-delivery is based on carbon dots was surface-modified with poly-ethylenimine (PEI), and loaded the siMRP1 and chemotherapeutics by electronstatic interactions on the surface with pH-triggered drug release. The CD-PEI was synthesized by one-step microwave assisted method; the PEI were raw materials and passivator during the reaction process that makes CD exhibit excellent optical property and the capability of loading siRNA. The CD-PEI was capable of loading and delivering siMRP1 and DOX to tumor and release synchronously in cell by pH-triggered manner using flow cytometry and confocal laser scanning microscopy analysis. MRP1 was successfully knocked down by siRNA. The silencing of MRP1 by co-delivery system could increase DOX accumulation and significantly enhance the inhibitory effect of metastatic potential elicited by doxorubicin in A549 and A549/ADM cells.ConclusionThe co-delivery systems effectively loaded and released siRNA and DOX agents to the targeted tumor, overcoming the resistant to chemotherapy. By suppressing MRP1, CD-PEI-DOX-siMRP1 can obviously increase the drug intercellular accumulation and inhibit the cell proliferation, migration and invasion, implying its potential application in enhancing therapeutic efficiency in clinical practices.

scholarly journals Assessment of Genes Associated with Streptococcus mutans Biofilm Morphology

2006 ◽  
Vol 72 (9) ◽  
pp. 6277-6287 ◽  
Author(s):  
Mizuho Motegi ◽  
Yuzo Takagi ◽  
Hideo Yonezawa ◽  
Nobuhiro Hanada ◽  
Jun Terajima ◽  
...  
Keyword(s):  
Streptococcus Mutans ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Protein Gene ◽  
Laser Scanning Microscopy ◽  
Live Cells ◽  
Confocal Laser ◽  
Morphological Development ◽  
Phosphotransferase System ◽  
Whole Saliva

ABSTRACT Streptococcus mutans, the major pathogen responsible for dental caries in humans, is a biofilm-forming bacterium. In the present study, 17 different pulsed-field gel electrophoresis patterns of genomic DNA were identified in S. mutans organisms isolated clinically from whole saliva. The S. mutans isolates showed different abilities to form biofilms on polystyrene surfaces in semidefined minimal medium cultures. Following cultivation in a flow cell system in tryptic soy broth with 0.25% sucrose and staining using a BacLight LIVE/DEAD system, two strains, designated FSC-3 and FSC-4, showed the greatest and least, respectively, levels of biofilm formation when examined with confocal laser scanning microscopy. Further, image analyses of spatial distribution and architecture were performed to quantify the merged green (live cells) and red (dead cells) light. The light intensity of the FSC-3 biofilm was greater than that of the FSC-4 biofilm in the bottom area but not in the top area. S. mutans whole-genome array results showed that approximately 3.8% of the genes were differentially expressed in the two strains, of which approximately 2.2%, including bacitracin transport ATP-binding protein gene glrA and a BLpL-like putative immunity protein gene, were activated in FSC-3. In addition, about 1.6% of the genes, including those associated with phosphotransferase system genes, were repressed. Analyses of the glrA-deficient strains and reverse transcription-PCR confirmed the role of the gene in biofilm formation. Differential assessment of biofilm-associated genes in clinical strains may provide useful information for understanding the morphological development of streptococcal biofilm, as well as for colonization of S. mutans.

scholarly journals Doxorubicin and siRNA Co-Delivery System Based on Carbon Dots Inhibits Metastasis of Lung Cancer by Attenuating Mrp1-Mediated Resistance

2020 ◽  
Author(s):  
Hui Luo ◽  
Kaichen Huang ◽  
Kexin Tang ◽  
Xi Lin ◽  
Chaoming Mei ◽  
...  
Keyword(s):  
Delivery System ◽  
Carbon Dots ◽  
Laser Scanning ◽  
Lung Tumor ◽  
Raw Materials ◽  
Bond Cleavage ◽  
Laser Scanning Microscopy ◽  
Migration And Invasion ◽  
Confocal Laser ◽  
Clinical Practices

Abstract BackgroundTumor easily develops resistance to anti-cancer drugs leading to decreased therapy efficiency of chemotherapies. Targeting signaling molecules related with chemoresistance through strategy of co-delivery siRNA and chemotherapeutics may overcome the multidrug resistance to chemotherapy. A co-delivery nanosystem that could carry siRNA and DOX simultaneously has been studied in this work. ResultsThe co-delivery is based on carbon dots was surface-modified with poly-ethylenimine (PEI), and loaded the siMRP1 and chemotherapeutics on the surface with pH-triggered drug release. The CD-PEI was synthesized by one-step microwave assisted method; the PEI were raw materials and passivator during the reaction process that makes CD exhibit excellent optical property. The CD-PEI was capable of loading and delivering siMRP1 and DOX to tumor and release synchronously in cell by acid-triggered manner, i.e. hydrazone bond cleavage and endosome/lysosome escape using flow cytometry and confocal laser scanning microscopy analysis. MRP1 was successfully knocked down by siRNA. The silencing of MRP1 by co-delivery system could increase DOX accumulation and significantly enhance the inhibitory effect of metastatic potential elicited by doxorubicin in A549 and A549/ADM cells.ConclusionThe co-delivery systems effectively loaded and released siRNA and DOX agents to the targeted lung tumor, overcoming the resistant to chemotherapy. By suppressing MRP1, CD-PEI-DOX-siMRP1 can obviously increase the drug intercellular accumulation and inhibit the cell proliferation, migration and invasion, implying its potential application in enhancing therapeutic efficiency in clinical practices.

Doxorubicin and siRNA Co-Delivery System Based on Carbon Dots Inhibits Chemoresistance of Lung Cancer

2021 ◽  
Author(s):  
Hui Luo ◽  
Kexin Tang ◽  
Kaichen Huang ◽  
Xi Lin ◽  
Chaoming Mei ◽  
...  
Keyword(s):  
Delivery System ◽  
Carbon Dots ◽  
Laser Scanning ◽  
Raw Materials ◽  
Metastatic Potential ◽  
Laser Scanning Microscopy ◽  
Migration And Invasion ◽  
Confocal Laser ◽  
Clinical Practices ◽  
Anti Cancer

Abstract BackgroundThe resistance to the anti-cancer agent limits the chemotherapy effect in the cancer therapy. Tumor easily develops resistance to anti-cancer drugs leading to decreased therapy efficiency of chemotherapies. Targeting signaling molecules related with chemoresistance through strategy of co-delivery siRNA and chemotherapeutics may overcome the multidrug resistance to chemotherapy. A co-delivery nanosystem that could carry siRNA and DOX simultaneously has been studied in this work. ResultsThe co-delivery is based on carbon dots was surface-modified with poly-ethylenimine (PEI), and loaded the siMRP1 and chemotherapeutics by electronstatic interactions on the surface with pH-triggered drug release. The CD-PEI was synthesized by one-step microwave assisted method; the PEI were raw materials and passivator during the reaction process that makes CD exhibit excellent optical property and the capability of loading siRNA. The CD-PEI was capable of loading and delivering siMRP1 and DOX to tumor and release synchronously in cell by pH-triggered manner using flow cytometry and confocal laser scanning microscopy analysis. MRP1 was successfully knocked down by siRNA. The silencing of MRP1 by co-delivery system could increase DOX accumulation and significantly enhance the inhibitory effect of metastatic potential elicited by doxorubicin in A549 and A549/ADM cells.ConclusionThe co-delivery systems effectively loaded and released siRNA and DOX agents to the targeted tumor, overcoming the resistant to chemotherapy. By suppressing MRP1, CD-PEI-DOX-siMRP1 can obviously increase the drug intercellular accumulation and inhibit the cell proliferation, migration and invasion, implying its potential application in enhancing therapeutic efficiency in clinical practices.

Starch Combined with Sucrose Provokes Greater Root Dentine Demineralization than Sucrose Alone

2018 ◽  
Vol 52 (4) ◽  
pp. 323-330
Author(s):  
Samilly Evangelista Souza ◽  
Aline Araújo Sampaio ◽  
Altair Antoninha Del Bel Cury ◽  
Yuri Wanderley Cavalcanti ◽  
Antônio Pedro Ricomini Filho ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Culture Medium ◽  
Surface Hardness ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Salivary Amylase ◽  
Cariogenic Bacteria ◽  
Ph Values ◽  
Biofilm Model ◽  
Whole Saliva

Since there is no consensus about whether starch increases the cariogenic potential of sucrose, we used a validated 3-species biofilm model to evaluate if starch combined with sucrose provokes higher root dentine demineralization than sucrose alone. Biofilms (n = 18) composed by Streptococcus mutans (the most cariogenic bacteria), Actinomces naeslundii (which has amylolytic activity), and Streptococcus gordonii (which binds salivary amylase) were formed on root dentine slabs under exposure 8 ×/day to one of the following treatments: 0.9% NaCl, 1% starch, 10% sucrose, or a combination of 1% starch and 10% sucrose. Before each treatment, biofilms were pretreated with human whole saliva for 1 min. The pH of the culture medium was measured daily as an indicator of biofilm acidogenicity. After 96 h of growth, the biofilms were collected, and the biomass, bacteria viability, and polysaccharides were analyzed. Dentine demineralization was assessed by surface hardness loss (% SHL). Biofilm bioarchitecture was analyzed using confocal laser scanning microscopy. Treatment with a starch and sucrose combination provoked higher (p = 0.01) dentine demineralization than sucrose alone (% SHL = 53.2 ± 7.0 vs. 43.2 ± 8.7). This was supported by lower pH values (p = 0.007) of the culture medium after daily exposure to the starch and sucrose combination compared with sucrose (4.89 ± 0.29 vs. 5.19 ± 0.32). Microbiological and biochemical findings did not differ between biofilms treated with the combination of starch and sucrose and sucrose alone (p > 0.05). Our findings give support to the hypothesis that a starch and sucrose combination is more cariogenic for root dentine than sucrose alone.

3-D imaging of cells using a confocal laser scanning microscope and digital image processing

1988 ◽  
Vol 46 ◽  
pp. 96-97
Author(s):  
Thomas M. Jovin ◽  
Michel Robert-Nicoud ◽  
Donna J. Arndt-Jovin ◽  
Thorsten Schormann
Keyword(s):  
Laser Scanning ◽  
Confocal Laser Scanning Microscope ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Confocal Laser ◽  
Scanning Microscope ◽  
Laser Scanning Microscope ◽  
Biochemical Processes ◽  
Adjacent Structures

Light microscopic techniques for visualizing biomolecules and biochemical processes in situ have become indispensable in studies concerning the structural organization of supramolecular assemblies in cells and of processes during the cell cycle, transformation, differentiation, and development. Confocal laser scanning microscopy offers a number of advantages for the in situ localization and quantitation of fluorescence labeled targets and probes: (i) rejection of interfering signals emanating from out-of-focus and adjacent structures, allowing the “optical sectioning” of the specimen and 3-D reconstruction without time consuming deconvolution; (ii) increased spatial resolution; (iii) electronic control of contrast and magnification; (iv) simultanous imaging of the specimen by optical phenomena based on incident, scattered, emitted, and transmitted light; and (v) simultanous use of different fluorescent probes and types of detectors.We currently use a confocal laser scanning microscope CLSM (Zeiss, Oberkochen) equipped with 3-laser excitation (u.v - visible) and confocal optics in the fluorescence mode, as well as a computer-controlled X-Y-Z scanning stage with 0.1 μ resolution.

Vacuoles Induced in Mammalian Cells by Helicobacter Cytotoxin are Acidic Organelles

1990 ◽  
Vol 48 (3) ◽  
pp. 168-169
Author(s):  
M. H. Chestnut ◽  
C. E. Catrenich
Keyword(s):  
Acridine Orange ◽  
Mammalian Cells ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Ulcer Disease ◽  
Gastroduodenal Disease ◽  
H Pylori

Helicobacter pylori is a non-invasive, Gram-negative spiral bacterium first identified in 1983, and subsequently implicated in the pathogenesis of gastroduodenal disease including gastritis and peptic ulcer disease. Cytotoxic activity, manifested by intracytoplasmic vacuolation of mammalian cells in vitro, was identified in 55% of H. pylori strains examined. The vacuoles increase in number and size during extended incubation, resulting in vacuolar and cellular degeneration after 24 h to 48 h. Vacuolation of gastric epithelial cells is also observed in vivo during infection by H. pylori. A high molecular weight, heat labile protein is believed to be responsible for vacuolation and to significantly contribute to the development of gastroduodenal disease in humans. The mechanism by which the cytotoxin exerts its effect is unknown, as is the intracellular origin of the vacuolar membrane and contents. Acridine orange is a membrane-permeant weak base that initially accumulates in low-pH compartments. We have used acridine orange accumulation in conjunction with confocal laser scanning microscopy of toxin-treated cells to begin probing the nature and origin of these vacuoles.

Sign in / Sign up

Export Citation Format

Share Document