Bacterial Adhesion on Polyelectrolyte Modified Microstructured Titanium Surfaces

2010 ◽  
Vol 1277 ◽  
Author(s):  
Argelia Almaguer-Flores ◽  
Yolloxóchilt R. Sánchez-Cruz ◽  
Jung Hwa Park ◽  
René Olivares-Navarrete ◽  
Michel Dard ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Bacterial Adhesion ◽  
Statistical Significance ◽  
Fusobacterium Nucleatum ◽  
Bacterial Attachment ◽  
Chemical Surface ◽  
Campylobacter Rectus ◽  
Submicron Scale ◽  
Student’S T

Micron-scale and submicron-scale surface roughness enhance osteoblast differentiation on titanium (Ti) substrates and increases bone-to-implant contact in vivo. However, bacterial adhesion is also strongly influenced by roughness and surface chemistry. The aim of this study was to investigate if chemical surface modifications alter initial bacterial attachment. To achieve this, two polyelectrolyte layers [chitosan (Ch) and poly(L-lysine) (PLL)] were used to coat Ti surfaces with different roughness (PT [Ra<0.3μm], SLA [Ra≥3.0μm]). Bacterial attachment was evaluated using Aggregatibacter actinomycetemcomitans, Actinomyces israelii, Campylobacter rectus, Eikenella corrodens, Fusobacterium nucleatum, Parvimonas micra, Porphyromonas gingivalis, Prevotella intermedia and Streptococcus sanguinis. After 24h incubation, bacteria were detached from the samples with sonication and the counting plate technique was performed to determine the number of colony forming units (CFU's). Additionally, surfaces were observed by scanning electron microscopy to determine bacteria surface coverage. Statistical significance was determined using ANOVA followed by Bonferroni's modification of Student's t-test. The results showed that polyelectrolyte coatings did not affect surface roughness. Modified surfaces were more hydrophilic than the controls. PT surfaces covered by Chi exhibited lower CFUs than the same surface covered by PLL or the control PT (140 × 105/mL, 343 × 105/mL and 283 × 105/mL, respectively). The opposite effect was observed on the SLA surfaces, PLL coated samples shown lower CFUʼs than Chi or uncoated SLA (199 × 105/mL, 229 × 105/mL and 227 × 105/mL, respectively). The Chi layer appeared to reduce bacterial adhesion only on the smooth surfaces. In contrast, PLL coatings reduced bacterial attachment on rougher surfaces. These results suggest that chemical modification of Ti without alteration of surface roughness affects oral bacterial attachment, and could be useful to prevent peri-implantitis related diseases.

scholarly journals Bacterial Adhesion at Synthetic Surfaces

1999 ◽  
Vol 65 (11) ◽  
pp. 4995-5002 ◽  
Author(s):  
D. Cunliffe ◽  
C. A. Smart ◽  
C. Alexander ◽  
E. N. Vulfson
Keyword(s):  
Molecular Weight ◽  
Protein Adsorption ◽  
Bacterial Adhesion ◽  
Cell Attachment ◽  
Systematic Investigation ◽  
Bacterial Attachment ◽  
E Coli ◽  
Glass Substrates ◽  
Cell Adsorption

ABSTRACT A systematic investigation into the effect of surface chemistry on bacterial adhesion was carried out. In particular, a number of physicochemical factors important in defining the surface at the molecular level were assessed for their effect on the adhesion ofListeria monocytogenes, Salmonella typhimurium,Staphylococcus aureus, and Escherichia coli. The primary experiments involved the grafting of groups varying in hydrophilicity, hydrophobicity, chain length, and chemical functionality onto glass substrates such that the surfaces were homogeneous and densely packed with functional groups. All of the surfaces were found to be chemically well defined, and their measured surface energies varied from 15 to 41 mJ · m−2. Protein adsorption experiments were performed with3H-labelled bovine serum albumin and cytochromec prior to bacterial attachment studies. Hydrophilic uncharged surfaces showed the greatest resistance to protein adsorption; however, our studies also showed that the effectiveness of poly(ethyleneoxide) (PEO) polymers was not simply a result of its hydrophilicity and molecular weight alone. The adsorption of the two proteins approximately correlated with short-term cell adhesion, and bacterial attachment for L. monocytogenes and E. coli also correlated with the chemistry of the underlying substrate. However, for S. aureus and S. typhimurium a different pattern of attachment occurred, suggesting a dissimilar mechanism of cell attachment, although high-molecular-weight PEO was still the least-cell-adsorbing surface. The implications of this for in vivo attachment of cells suggest that hydrophilic passivating groups may be the best method for preventing cell adsorption to synthetic substrates provided they can be grafted uniformly and in sufficient density at the surface.

scholarly journals The membrane microenvironment regulates the sequential attachment of bacteria to host cells

2020 ◽  
Author(s):  
Xavier Pierrat ◽  
Jeremy P.H. Wong ◽  
Zainebe Al-Mayyah ◽  
Alexandre Persat
Keyword(s):  
Cell Surface ◽  
Host Cell ◽  
Bacterial Adhesion ◽  
Bacterial Attachment ◽  
Host Cells ◽  
Receptor System ◽  
Surface Receptors ◽  
Inert Surfaces ◽  
Mechanical Microenvironment

AbstractPathogen attachment to host tissue is critical in the progress of many infections. Bacteria use adhesion in vivo to promote colonization and regulate the deployment of contact-dependent virulence traits. To specifically target host cells, they decorate themselves with adhesins, proteins that bind to mammalian cell surface receptors. One common assumption is that adhesin-receptor interactions entirely govern bacterial attachment. However, how adhesins engage with their receptors in an in vivo-like context remains unclear, in particular under the influence of a heterogeneous mechanical microenvironment. We here investigate the biophysical processes governing bacterial adhesion to host cells using a tunable adhesin-receptor system. By dynamically visualizing attachment, we found that bacterial adhesion to host cell surface, unlike adhesion to inert surfaces, involves two consecutive steps. Bacteria initially attach to their host without engaging adhesins. This step lasts about one minute during which bacteria can easily detach. We found that at this stage, the glycocalyx, a layer of glycosylated proteins and lipids, shields the host cell by keeping adhesin away from their receptor ligand. In a second step, adhesins engage with their target receptors to strengthen attachment for minutes to hours. The active properties of the membrane, endowed by the actin cytoskeleton, strengthen specific adhesion. Altogether, our results demonstrate that adhesin-ligand binding is not the sole regulator of bacterial adhesion. In fact, the host cell’s mechanical microenvironment relatively strongly mediated host-bacteria physical interactions, thereby playing an essential role in the onset of infection.

scholarly journals Influence of Photon-Induced Photoacoustic Streaming (PIPS) on Root Canal Disinfection and Post-Operative Pain: A Randomized Clinical Trial

2020 ◽  
Vol 9 (12) ◽  
pp. 3915
Author(s):  
Narcisa Mandras ◽  
Damiano Pasqualini ◽  
Janira Roana ◽  
Vivian Tullio ◽  
Giuliana Banche ◽  
...  
Keyword(s):  
Root Canal ◽  
Statistical Significance ◽  
Bacterial Count ◽  
Microbiological Analysis ◽  
Root Canal Disinfection ◽  
Before And After ◽  
Traditional Irrigation ◽  
Student’S T ◽  
Group B

The aim of this study was to evaluate the ability of a PIPS (photon-induced photoacoustic streaming) Er:YAG laser to reduce the root canal system bacterial count in vivo in comparison to the traditional irrigation technique. The post-operative patients’ quality of life (QoL) after endodontic therapy was evaluated through a questionnaire. Fifty-four patients affected by pulp necrosis with or without apical periodontitis biofilm disease were selected for endodontic treatment and randomly assigned to Group A (n = 27) with traditional irrigation and Group B (n = 27), with PIPS irrigation applied according to the protocol. Shaping was performed with ProGlider and ProTaper Next, and irrigation was performed with 5% NaOCl and 10% EDTA. Intracanal samples for culture tests were collected before and after irrigation. The microbiological analysis was evaluated by the Kolmogorov–Smirnov normality and Mann–Whitney tests (p < 0.05). A self-assessment questionnaire was used to evaluate the QoL during the 7 days after treatment; differences were analysed with Student’s t-test. Irrigation with the PIPS device was significantly effective in reducing bacterial counts, which were higher for facultative than obligate anaerobic strains, particularly for Gram-negative bacteria, without statistical significance (p > 0.05). There were no significant differences among the QoL indicators, except for the maximum pain (p = 0.02), eating difficulty (p = 0.03) and difficulty performing daily functions (p = 0.02) in the first few days post-treatment. PIPS may represent an aid to root canal disinfection not affecting the patients’ QoL, particularly for the first day after treatment.

Antibacterial Effect of Biodegradable Magnesium Alloys Modified By Biocompatible Transitions Metals

2010 ◽  
Vol 1277 ◽  
Author(s):  
V.I. García-Pérez ◽  
A. Almaguer-Flores ◽  
C. Ramírez-Brizuela ◽  
S.E. Rodil
Keyword(s):  
Electron Microscopy ◽  
Stainless Steel ◽  
Magnesium Alloys ◽  
Bacterial Adhesion ◽  
Fusobacterium Nucleatum ◽  
Control Surface ◽  
Bacterial Strains ◽  
Campylobacter Rectus ◽  
Steel Aisi ◽  
Biofilm Development

Magnesium (Mg) alloys can be use as biodegradable medical devices, eliminating the need for a second operation for implant removal. An important feature on biomedical devices is to avoid the bacterial adhesion and subsequent biofilm formation that cause most of the implant-failures. The aim of this study was to analyze the differences on bacterial adhesion and biofilm development on Magnesium alloys (Mg-Al-Zn) modified by different transition metals; Tantalum, Niobium and Titanium. Nine oral bacterial strains (Aggregatibacter actinomycetemcomitans serotipe b, Actinomyces israelii, Campylobacter rectus, Eikenella corrodens, Fusobacterium nucleatum, Parvimonas micra, Porphyromonas gingivalis, Prevotella intermedia and Streptococcus sanguinis) were incubated on the different alloys and commercial medical grade stainless steel (AISI 316L) was used as a control. The initial bacterial adhesion was determined after 24 hours using a counting plate technique and the subsequent biofilm development at 1, 3, 7 days was studied using the Scanning Electron Microscopy. Significant differences were determined using t-test. The results showed that on the magnesium-alloys, the number of bacteria attached after 24 hours was two orders of magnitude lower than the stainless steel. On the other hand, bacterial colonies were not observed by electron microscopy in any of the days of incubation, even though in the control surface clear colonies and biofilm development were observed. This study showed that magnesium alloys inhibits the bacterial adhesion and the subsequent biofilm development.

scholarly journals Initial Bacterial Adhesion and Biofilm Formation on Aligner Materials

Antibiotics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 908
Author(s):  
Sibel Tektas ◽  
Thomas Thurnheer ◽  
Theodore Eliades ◽  
Thomas Attin ◽  
Lamprini Karygianni
Keyword(s):  
Bacterial Adhesion ◽  
Biofilm Formation ◽  
Statistical Significance ◽  
Sample Surface ◽  
Human Saliva ◽  
Bacterial Attachment ◽  
Columbia Blood Agar ◽  
Conventional Brackets ◽  
Aerobic And Anaerobic

The present study aims to assess the initial bacterial adhesion and biofilm formation on different aligner materials. A total of four different aligner materials, CA-medium (CAM), copolyester (COP), Duran (DUR), Erkodur (ERK), were tested. Stimulated human saliva was obtained from six healthy volunteers. Salivary bacteria were harvested by centrifugation, and 1 mL of the salivary suspension was injected onto each sample surface for 2 h and 3 days, respectively. The samples were then washed twice with 5 mL 0.9% NaCl solution, and non-adherent bacteria were removed. The adherent microorganisms were dislodged from the sample surfaces after ultrasonication for 4 min in 1 mL 0.9% NaCl on ice. After the incubation of the adherent salivary bacteria under both aerobic and anaerobic conditions on Columbia blood agar plates at 37 °C and 5% CO2 and in anaerobic jars overnight, several dilutions thereof were used for the determination of CFUs. This protocol was applied three times, obtaining an average of nine independent measurements for each material group. Overall, the differences between the tested aligner materials as well as between the materials and controls were not of statistical significance (p > 0.05). Regarding initial bacterial attachment and biofilm formation, the tested aligner materials are comparable to enamel and metal orthodontic brackets and can be therefore considered for clinical use. The four tested aligner materials CAM, COP, DUR, ERK showed no significant differences in initial microbial attachment and biofilm formation of aerobic and anaerobic species compared to enamel and conventional brackets.

scholarly journals In vitro and in vivo biofilm adhesion to esthetic coated arch wires and its correlation with surface roughness

2015 ◽  
Vol 86 (2) ◽  
pp. 285-291 ◽  
Author(s):  
Mahasen Taha ◽  
Abeer El-Fallal ◽  
Heba Degla
Keyword(s):  
Surface Roughness ◽  
Bacterial Adhesion ◽  
Test Analysis ◽  
Positive Correlation ◽  
Oral Biofilms ◽  
Orthodontic Patients ◽  
In Vitro Adhesion ◽  
Level Of Significance

ABSTRACT Objective:  To evaluate the in vitro ability of esthetic coated rectangular arch wires to retain oral biofilms and in vivo biofilm formation on these wires after 4 and 8 weeks of clinical use and to correlate the findings with the surface roughness of these wires. Materials and Methods:  Three brands of esthetic coated nickel-titanium (NiTi) arch wires were selected. Arch wires retrieved after 4 and 8 weeks of intraoral use were obtained from 30 orthodontic patients. Surface roughness (SR) was assessed with an atomic force microscope. In vitro adhesion assays were performed using Streptococcus mutans (MS), Staphylococcus aureus, and Candida albicans. The amount of bacterial adhesion was quantified using the colony-count method. Paired t-test, analysis of variance, post hoc Tukey's test, and Pearson's correlation coefficient test were used for statistical analysis at the .05 level of significance. Results:  In vitro bacterial adhesion showed significant differences between wires in terms of MS adhesion (P  =  .01). All wires showed significant increases in SR (P  =  .001 after 4 weeks and .007 after 8 weeks) and biofilm adhesion (P  =  .0001 after 4 weeks and .045 after 8 weeks) after intraoral exposure. A significant positive correlation (P  =  .001 after 4 weeks and .05 after 8 weeks) was observed between these two variables in vivo, but the correlation was not significant for in vitro bacterial adhesion. Conclusions:  SR and biofilm adhesion increased after intraoral use at all time intervals. There was a positive correlation between SR and biofilm adhesion in vivo only.

Scientific Substantiation of the Innovative Model of Catering for Cadet Corps Students

2020 ◽  
pp. 31-35
Author(s):  
Novikova ◽  
SP Romanenko ◽  
MA Lobkis
Keyword(s):  
Correlation Coefficient ◽  
School Environment ◽  
Developmental Disorders ◽  
Pearson Correlation ◽  
Statistical Significance ◽  
Regression Analyses ◽  
Healthy Nutrition ◽  
Innovative Model ◽  
Scientific Substantiation ◽  
Student’S T

Introduction: In the Russian Federation, much attention is traditionally paid to military education and training. A special place in its structure is occupied by the system of cadet classes and corps. A distinctive feature of the learning mode in such institutions is a combined effect of standard and specific factors of indoor school environment and intensive physical activity owing to sports, applied military and drill training. No evidence-based methods of establishing nutrient requirements of children in modern conditions of cadet corps have been developed so far, which predetermines the potential of transforming nutrition from a health-saving factor into a health risk factor. Our objective was to provide a scientific substantiation of the model of healthy nutrition for students of cadet-type educational establishments. Methods: The statistical significance of the correlation was evaluated using the Student’s t-test. Correlation and regression analyses were used to assess cause-and-effect relationships. The Pearson correlation coefficient (rxy) was used as an indicator of the strength of the relationship between quantitative indicators x and y, both having a normal distribution. Correlation coefficient (rxy) values were interpreted in accordance with the Chaddock scale. For the purpose of statistical modeling, the method of multiple linear regressions was used. Conclusions: We substantiated the innovative model of organizing healthy nutrition for students of cadet-type schools based on the correlation and regression analyses with determination of statistical significance of the studied characteristics. Its efficiency indicators include an increase in average functional capabilities of students by more than 10 % and a reduction in the probability of developmental disorders by more than 25 %.

Carbon dots derived from Fusobacterium nucleatum for intracellular determination of Fe3+ and bioimaging both in vitro and in vivo

2021 ◽  
Author(s):  
Lijuan Liu ◽  
Shengting Zhang ◽  
Xiaodan Zheng ◽  
Hongmei Li ◽  
Qi Chen ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Fusobacterium Nucleatum ◽  
Living Cells ◽  
First Time ◽  
Fluorescent Carbon Dots ◽  
Fluorescent Carbon

Fusobacterium nucleatum has been employed for the first time to synthesize fluorescent carbon dots which could be applied for the determination of Fe3+ ions in living cells and bioimaging in vitro and in vivo with excellent biocompatibility.

scholarly journals Whole-brain 3D MR fingerprinting brain imaging: clinical validation and feasibility to patients with meningioma

2021 ◽  
Author(s):  
Thomaz R. Mostardeiro ◽  
Ananya Panda ◽  
Robert J. Witte ◽  
Norbert G. Campeau ◽  
Kiaran P. McGee ◽  
...  
Keyword(s):  
White Matter ◽  
Statistical Significance ◽  
Relaxation Times ◽  
Brain Structures ◽  
Centrum Semiovale ◽  
In Vivo Evaluation ◽  
Whole Brain ◽  
Mean Values ◽  
Caudate Head

Abstract Purpose MR fingerprinting (MRF) is a MR technique that allows assessment of tissue relaxation times. The purpose of this study is to evaluate the clinical application of this technique in patients with meningioma. Materials and methods A whole-brain 3D isotropic 1mm3 acquisition under a 3.0T field strength was used to obtain MRF T1 and T2-based relaxometry values in 4:38 s. The accuracy of values was quantified by scanning a quantitative MR relaxometry phantom. In vivo evaluation was performed by applying the sequence to 20 subjects with 25 meningiomas. Regions of interest included the meningioma, caudate head, centrum semiovale, contralateral white matter and thalamus. For both phantom and subjects, mean values of both T1 and T2 estimates were obtained. Statistical significance of differences in mean values between the meningioma and other brain structures was tested using a Friedman’s ANOVA test. Results MR fingerprinting phantom data demonstrated a linear relationship between measured and reference relaxometry estimates for both T1 (r2 = 0.99) and T2 (r2 = 0.97). MRF T1 relaxation times were longer in meningioma (mean ± SD 1429 ± 202 ms) compared to thalamus (mean ± SD 1054 ± 58 ms; p = 0.004), centrum semiovale (mean ± SD 825 ± 42 ms; p < 0.001) and contralateral white matter (mean ± SD 799 ± 40 ms; p < 0.001). MRF T2 relaxation times were longer for meningioma (mean ± SD 69 ± 27 ms) as compared to thalamus (mean ± SD 27 ± 3 ms; p < 0.001), caudate head (mean ± SD 39 ± 5 ms; p < 0.001) and contralateral white matter (mean ± SD 35 ± 4 ms; p < 0.001) Conclusions Phantom measurements indicate that the proposed 3D-MRF sequence relaxometry estimations are valid and reproducible. For in vivo, entire brain coverage was obtained in clinically feasible time and allows quantitative assessment of meningioma in clinical practice.

Effect of surface sealant on surface roughness and bacterial adhesion of bulk-fill composites

2021 ◽  
pp. 096739112110055
Author(s):  
Gunce Ozan ◽  
Meltem Mert Eren ◽  
Cansu Vatansever ◽  
Ugur Erdemir
Keyword(s):  
Surface Roughness ◽  
Bacterial Adhesion ◽  
Confocal Laser ◽  
High Caries Risk ◽  
Two Samples ◽  
Significant Difference ◽  
Restorative Materials ◽  
Surface Sealants ◽  
Surface Sealant ◽  
Effect Of Surface

Surface sealants are reported to ensure surface smoothness and improve the surface quality of composite restorations. These sealants should also reduce the bacterial adhesion on composite surfaces however, there is not much information regarding their performance on bulk-fill composite materials. The aim of this study was to evaluate the effect of surface sealant application on surface roughness and bacterial adhesion of various restorative materials. Disc-shaped samples were prepared from a compomer, a conventional composite and three bulk-fill composites. Specimens of each group were divided into two groups (n = 9): with/without surface sealant (Biscover LV, [BLV]). Surface roughness values were examined by profilometry and two samples of each group were examined for bacterial adhesion on a confocal laser scanning microscope (CLSM). Bacterial counts were calculated by both broth cultivation and microscopic images. Results were analyzed with one-way ANOVA and Bonferroni/Dunn tests. Following the BLV application, there was a decrease in the surface roughness values of all groups however, only Tetric N-Ceram Bulk and Beautifil-Bulk groups showed significantly smoother surfaces (p < 0.001). There were no significant differences among material groups without BLV application. Evaluating bacterial adhesion after BLV application, conventional composite had the lowest values among all followed by the compomer group. Beautifil-Bulk had significantly the highest bacterial adhesion (p < 0.05), followed by Tetric N-Ceram Bulk group. Without BLV application, there was no significant difference among bacterial adhesion values of groups (p > 0.05). CLSM images showed cell viability in groups. Bulk-fill composites showed higher bacterial adhesion than conventional composite and compomer materials. The surface sealant was found to be highly effective in lowering bacterial adhesion, but not so superior in smoothing the surfaces of restorative materials. So, surface sealants could be used on the restorations of patients with high caries risk.

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