scholarly journals Antibacterial Polysiloxane Polymers and Coatings for Cochlear Implants

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4892
Author(s):  
Vlad Cozma ◽  
Irina Rosca ◽  
Luminita Radulescu ◽  
Cristian Martu ◽  
Valentin Nastasa ◽  
...  
Keyword(s):  
Standardized Tests ◽  
Cochlear Implants ◽  
Biofilm Formation ◽  
Chemical Structure ◽  
New Materials ◽  
Characterization Methods ◽  
Morphological Aspects ◽  
Before And After ◽  
Microbial Adherence

Within this study, new materials were synthesized and characterized based on polysiloxane modified with different ratios of N-acetyl-l-cysteine (NAC) and crosslinked via UV-assisted thiol-ene addition, in order to obtain efficient membranes able to resist bacterial adherence and biofilm formation. These membranes were subjected to in vitro testing for microbial adherence against S. pneumoniae using standardized tests. WISTAR rats were implanted for 4 weeks with crosslinked siloxane samples without and with NAC. A set of physical characterization methods was employed to assess the chemical structure and morphological aspects of the new synthetized materials before and after contact with the microbiological medium.

scholarly journals Highly variable effect of sonication to dislodge biofilm-embedded Staphylococcus epidermidis directly quantified by epifluorescence microscopy: an in vitro model study

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Erik T. Sandbakken ◽  
Eivind Witsø ◽  
Bjørnar Sporsheim ◽  
Kjartan W. Egeberg ◽  
Olav A. Foss ◽  
...  
Keyword(s):  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
In Vitro Model ◽  
Laser Scanning Microscopy ◽  
Epifluorescence Microscopy ◽  
Variable Effect ◽  
Prosthetic Joint Infections ◽  
Before And After ◽  
Vitro Model

Abstract Background In cases of prosthetic joint infections, culture of sonication fluid can supplement culture of harvested tissue samples for correct microbial diagnosis. However, discrepant results regarding the increased sensitivity of sonication have been reported in several studies. To what degree bacteria embedded in biofilm are dislodged during the sonication process has to our knowledge not been fully elucidated. In the present in vitro study, we have evaluated the effect of sonication as a method to dislodge biofilm by quantitative microscopy. Methods We used a standard biofilm method to cover small steel plates with biofilm forming Staphylococcus epidermidis ATCC 35984 and carried out the sonication procedure according to clinical practice. By comparing area covered with biofilm before and after sonication with epifluorescence microscopy, the effect of sonication on biofilm removal was quantified. Two series of experiments were made, one with 24-h biofilm formation and another with 72-h biofilm formation. Confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) were used to confirm whether bacteria were present after sonication. In addition, quantitative bacteriology of sonication fluid was performed. Results Epifluorescence microscopy enabled visualization of biofilm before and after sonication. CLSM and SEM confirmed coccoid cells on the surface after sonication. Biofilm was dislodged in a highly variable manner. Conclusion There is an unexpected high variation seen in the ability of sonication to dislodge biofilm-embedded S. epidermidis in this in vitro model.

scholarly journals Interaction Between Chitosan and Mucin: Fundamentals and Applications

Biomimetics ◽  
2019 ◽  
Vol 4 (2) ◽  
pp. 32 ◽  
Author(s):  
Collado-González ◽  
González Espinosa ◽  
Goycoolea
Keyword(s):  
Drug Delivery ◽  
Chemical Structure ◽  
Molecular Level ◽  
Ex Vivo ◽  
Biological Properties ◽  
Characterization Methods ◽  
Variable Chemical ◽  
And Behavior ◽  
Structure Properties

The term chitosan (CS) refers to a family of aminopolysaccharides derived from chitin. Among other properties, CS is nontoxic, mucoadhesive and can be used for load and transport drugs. Given these and other physicochemical and biological properties, CS is an optimal biopolymer for the development of transmucosal drug delivery systems, as well as for the treatment of pathologies related to mucosal dysfunctions. Mucins are glycoprotein macromolecules that are the major components of mucus overlaying epithelia. CS interacts with mucin and adsorbs on and changes the rheology of mucus. However, CS and mucins denote families of polymers/macromolecules with highly variable chemical structure, properties, and behavior. To date, their interactions at the molecular level have not been completely unraveled. Also, the properties of complexes composed of CS and mucin vary as a function of the sources and preparation of the polymers. As a consequence, the mucoadhesion and drug delivery properties of such complexes vary as well. The breadth of this review is on the molecular interactions between CS and mucin. In particular, in vitro and ex vivo characterization methods to investigate both the interactions at play during the formation of CS-mucin complexes, and the advances on the use of CS for transmucosal drug delivery are addressed.

scholarly journals Bacterial biofilm formation on cochlear implants in vitro

2018 ◽  
Author(s):  
B Höing ◽  
L Kirchhoff ◽  
J Arnolds ◽  
S Lang ◽  
J Steinmann ◽  
...  
Keyword(s):  
Cochlear Implants ◽  
Biofilm Formation ◽  
Bacterial Biofilm

scholarly journals Lack of effect of cell-wall targeted antibacterials on biofilm formation and antifungal susceptibility of Candidaspecies

2014 ◽  
Vol 50 (3) ◽  
pp. 467-472
Author(s):  
Gisela Myrian de Lima Leite ◽  
Lílian Cristiane Baeza ◽  
Rosana Teixeira Ramos ◽  
Sérgio Seiji Yamada ◽  
Thiago Ferreira dos Santos Magon ◽  
...  
Keyword(s):  
Cell Wall ◽  
Biofilm Formation ◽  
Antifungal Agents ◽  
Antifungal Susceptibility ◽  
Central Venous ◽  
In Vitro Susceptibility ◽  
Mueller Hinton ◽  
Before And After ◽  
Mueller Hinton Agar

The use of central venous catheters (CVC) and broad-spectrum antibacterials are among the main risk factors for the development of candidemia in patients admitted to intensive care units (ICU). It is known that some antibacterials increase the resistance of these yeasts to azole antifungals. Thus, the aim of this research was to determine whether yeast present in CVC colonizations previously exposed to cell-wall targeted antibacterials benefit from a reduction in susceptibility to fluconazole and voriconazole, facilitating their ability to form biofilms. Candida albicans, C. tropicalis, C. glabrata, C. parapsilosis and C. guilhermondii were seeded into antibacterial (cefepime, meropenem, vancomycin, and piperacillin-tazobactam) gradient plates produced in Mueller-Hinton Agar. The susceptibility to fluconazole and voriconazole and the biofilm formation of the yeasts were tested before and after exposure to the antibacterials. None of the antibacterials exerted a significant effect on the in vitro susceptibility of the yeasts to the antifungal agents or on their ability to form biofilms. These results suggest that increased candidemia in ICU patients is not attributable to possible alterations in the yeasts, but is more likely caused by a weakening of the patient's general condition after long exposure to infection.

scholarly journals In vitro Macro-qualitative Comparison of Three Enamel Stripping Procedures: What is the Best Shape We can get?

2017 ◽  
Vol 10 (4) ◽  
pp. 358-362
Author(s):  
Mona N Gholmieh
Keyword(s):  
Initial Contour ◽  
Qualitative Comparison ◽  
Proximal Surface ◽  
Morphological Aspects ◽  
Before And After ◽  
Natural Teeth ◽  
Metallic Strip ◽  
Group B ◽  
Group D

ABSTRACT Aim Interdental stripping is a common clinical procedure in orthodontic therapy, by reshaping the proximal contacts. Handheld abrasive strips have been criticized as time-consuming process. Metallic strip system, diamond disk, or segment disks have become increasingly popular. The aim of this study is to evaluate the morphological aspects of remodeled dental surfaces so as to conclude which of the different techniques (disk, bur, or strip) used to reduce the mesiodistal diameter is the best to reproduce the initial contour of the proximal surface of the tooth. Materials and methods Seventy-nine pieces (“teeth”) were prepared from permanent healthy teeth (premolars and molars) extracted for orthodontic reasons. They were mounted on a stand resembling the position of the natural teeth in a mild crowded dentition. The “teeth” are divided into three groups as follows: group S (strip): 26 “teeth,” group D (disk): 25 “teeth,” group B (bur): 28 “teeth.” In order to study the changes, these prepared “teeth” are macro-photographed in groups of 5 before and after proximal grinding. Results The “teeth” contours have been identified using piecewise cubic Hermit polynomials. The change in the contour has been traduced in terms of the change of curvature in the “teeth” contours. We used the z-test in order to find the confidence interval for the proportion of the class “+” for each of the techniques B, S, and D. With confidence level of 95%, we obtained the following confidence intervals: B = (0.6943; 0.9057); S = (0.9093; 1.0138); D = (0.6184; 0.8616) These results can be interpreted, as the technique S is significantly much better than the other two techniques if we aim at conserving the shape of the teeth before and after treatment. Conclusion We conclude that the use of a strip for remodeling the proximal surface of a tooth is an optimal technique to preserve the proximal shape of the tooth although it requires more time. Clinical significance The use of abrasive strip preserves the best shape of the proximal side. Abrasive strip could be the last step of any proximal reshaping technique. How to cite this article Nassif N, Gholmieh MN, Sfeir E, Mourad A. In vitro Macro-qualitative Comparison of Three Enamel Stripping Procedures: What is the Best Shape We can get? Int J Clin Pediatr Dent 2017;10(4):358-362

Biofilm formation in cochlear implants with cochlear drug delivery channels in an in vitro model

2007 ◽  
Vol 136 (4) ◽  
pp. 577-582 ◽  
Author(s):  
Trey A. Johnson ◽  
Kimberly A. Loeffler ◽  
Robert A. Burne ◽  
Claude N. Jolly ◽  
Patrick J. Antonelli
Keyword(s):  
Drug Delivery ◽  
Cochlear Implants ◽  
Biofilm Formation ◽  
In Vitro Model ◽  
Vitro Model

Biofilm formation in an in vitro model of cochlear implants with removable magnets

2007 ◽  
Vol 136 (4) ◽  
pp. 583-588 ◽  
Author(s):  
Kimberly A. Loeffler ◽  
Trey A. Johnson ◽  
Robert A. Burne ◽  
Patrick J. Antonelli
Keyword(s):  
Cochlear Implants ◽  
Biofilm Formation ◽  
In Vitro Model ◽  
Vitro Model

Electron microscopic study of the membrane glycoproteins in the rat kidney after cisplatin treatment

1989 ◽  
Vol 47 ◽  
pp. 912-913
Author(s):  
S.K. Aggarwal
Keyword(s):  
Alkaline Phosphatase ◽  
Rat Kidney ◽  
Light And Electron Microscopy ◽  
Kidney Tissue ◽  
Membrane Glycoproteins ◽  
Electron Microscopic ◽  
Before And After ◽  
Interstrand Cross Links ◽  
Cross Links

The proposed primary mechanism of action of the anticancer drug cisplatin (Cis-DDP) is through its interaction with DNA, mostly through DNA intrastrand cross-links or DNA interstrand cross-links. DNA repair mechanisms can circumvent this arrest thus permitting replication and transcription to proceed. Various membrane transport enzymes have also been demonstrated to be effected by cisplatin. Glycoprotein alkaline phosphatase was looked at in the proximal tubule cells before and after cisplatin both in vivo and in vitro for its inactivation or its removal from the membrane using light and electron microscopy.Outbred male Swiss Webster (Crl: (WI) BR) rats weighing 150-250g were given ip injections of cisplatin (7mg/kg). Animals were killed on day 3 and day 5. Thick slices (20-50.um) of kidney tissue from treated and untreated animals were fixed in 1% buffered glutaraldehyde and 1% formaldehyde (0.05 M cacodylate buffer, pH 7.3) for 30 min at 4°C. Alkaline phosphatase activity and carbohydrates were demonstrated according to methods described earlier.

Structural integrity after cold storage of human epidermal model in hypothermosol: A correlative ultrastructural and fluorescent assay

1994 ◽  
Vol 52 ◽  
pp. 270-271
Author(s):  
Henry H. Eichelberger ◽  
John G. Baust ◽  
Robert G. Van Buskirk
Keyword(s):  
Cold Storage ◽  
Structural Integrity ◽  
Culture Media ◽  
Cell Structure ◽  
Natural State ◽  
Sodium Cacodylate ◽  
Ruthenium Tetroxide ◽  
Cacodylate Buffer ◽  
Before And After

For research in cell differentiation and in vitro toxicology it is essential to provide a natural state of cell structure as a benchmark for interpreting results. Hypothermosol (Cryomedical Sciences, Rockville, MD) has proven useful in insuring the viability of synthetic human epidermis during cold-storage and in maintaining the epidermis’ ability to continue to differentiate following warming.Human epidermal equivalent, EpiDerm (MatTek Corporation, Ashland, MA) consisting of fully differentiated stratified human epidermal cells were grown on a microporous membrane. EpiDerm samples were fixed before and after cold-storage (4°C) for 5 days in Hypothermosol or skin culture media (MatTek Corporation) and allowed to recover for 7 days at 37°C. EpiDerm samples were fixed 1 hour in 2.5% glutaraldehyde in sodium cacodylate buffer (pH 7.2). A secondary fixation with 0.2% ruthenium tetroxide (Polysciences, Inc., Warrington, PA) in sodium cacodylate was carried out for 3 hours at 4°C. Other samples were similarly fixed, but with 1% Osmium tetroxide in place of ruthenium tetroxide. Samples were dehydrated through a graded acetone series, infiltrated with Spurrs resin (Polysciences Inc.) and polymerized at 70°C.

Inhibitory effects of bioaccessible anthocyanins and procyanidins from apple, red grape, cinnamon on α-amylase, α-glucosidase and lipase

2020 ◽  
pp. 1-9
Author(s):  
Pınar Ercan ◽  
Sedef Nehir El
Keyword(s):  
Inhibitory Activity ◽  
Digestive Enzymes ◽  
Positive Control ◽  
Anthocyanin Content ◽  
Inhibitory Effects ◽  
Total Anthocyanin ◽  
Total Anthocyanin Content ◽  
Before And After ◽  
Red Grape

Abstract. The goals of this study were to determine and evaluate the bioaccessibility of total anthocyanin and procyanidin in apple (Amasya, Malus communis), red grape (Papazkarası, Vitis vinifera) and cinnamon (Cassia, Cinnamomum) using an in vitro static digestion system based on human gastrointestinal physiologically relevant conditions. Also, in vitro inhibitory effects of these foods on lipid (lipase) and carbohydrate digestive enzymes (α-amylase and α-glucosidase) were performed with before and after digested samples using acarbose and methylumbelliferyl oleate (4MUO) as the positive control. While the highest total anthocyanin content was found in red grape (164 ± 2.51 mg/100 g), the highest procyanidin content was found in cinnamon (6432 ± 177.31 mg/100 g) (p < 0.05). The anthocyanin bioaccessibilities were found as 10.2 ± 1%, 8.23 ± 0.64%, and 8.73 ± 0.70% in apple, red grape, and cinnamon, respectively. The procyanidin bioaccessibilities of apple, red grape, and cinnamon were found as 17.57 ± 0.71%, 14.08 ± 0.74% and 18.75 ± 1.49%, respectively. The analyzed apple, red grape and cinnamon showed the inhibitory activity against α-glucosidase (IC50 544 ± 21.94, 445 ± 15.67, 1592 ± 17.58 μg/mL, respectively), α-amylase (IC50 38.4 ± 7.26, 56.1 ± 3.60, 3.54 ± 0.86 μg/mL, respectively), and lipase (IC50 52.7 ± 2.05, 581 ± 54.14, 49.6 ± 2.72 μg/mL), respectively. According to our results apple, red grape and cinnamon have potential to inhibit of lipase, α-amylase and α-glucosidase digestive enzymes.

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