scholarly journals One-step preparation of antimicrobial silicone materials based on PDMS and salicylic acid: insights from spatially and temporally resolved techniques

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Luca Barbieri ◽  
Ioritz Sorzabal Bellido ◽  
Alison J. Beckett ◽  
Ian A. Prior ◽  
Jo Fothergill ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Laser Scanning ◽  
Pathogenic Bacteria ◽  
Pharmaceutical Products ◽  
Laser Scanning Microscopy ◽  
Wound Dressings ◽  
Confocal Laser ◽  
Vis Spectroscopy ◽  
Wide Range ◽  
One Step

AbstractIn this work, we introduce a one-step strategy that is suitable for continuous flow manufacturing of antimicrobial PDMS materials. The process is based on the intrinsic capacity of PDMS to react to certain organic solvents, which enables the incorporation of antimicrobial actives such as salicylic acid (SA), which has been approved for use in humans within pharmaceutical products. By combining different spectroscopic and imaging techniques, we show that the surface properties of PDMS remain unaffected while high doses of the SA are loaded inside the PDMS matrix. The SA can be subsequently released under physiological conditions, delivering a strong antibacterial activity. Furthermore, encapsulation of SA inside the PDMS matrix ensured a diffusion-controlled release that was tracked by spatially resolved Raman spectroscopy, Attenuated Total Reflectance IR (ATR-IR), and UV-Vis spectroscopy. The biological activity of the new material was evaluated directly at the surface and in the planktonic state against model pathogenic bacteria, combining confocal laser scanning microscopy, electron microscopy, and cell viability assays. The results showed complete planktonic inhibition for clinically relevant strains of Staphylococcus aureus and Escherichia coli, and a reduction of up to 4 orders of magnitude for viable sessile cells, demonstrating the efficacy of these surfaces in preventing the initial stages of biofilm formation. Our approach adds a new option to existing strategies for the antimicrobial functionalisation of a wide range of products such as catheters, wound dressings and in-dwelling medical devices based on PDMS.

scholarly journals Enhanced Grain-boundary Emission Lifetime and Additive Induced Crystal Orientation in One-Step Spin-Coated Mixed Cationic (FA/MA) Lead Perovskite Thin Films Stabilized by Zinc Iodide Doping

2017 ◽  
Author(s):  
René M. Williams ◽  
Loreta A. Muscarella ◽  
Dina Petrova ◽  
Rebecca Jorge Cervasio ◽  
Aram Farawar ◽  
...  
Keyword(s):  
Thin Films ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Crystal Formation ◽  
Ambient Conditions ◽  
Emission Lifetime ◽  
Photoluminescence Lifetime ◽  
One Step ◽  
Zinc Iodide

Mixed cationic lead perovskites containing formamidinium and methylammonium can be stabilized by incorporating ZnI<sub>2 </sub>as an “internal desiccant”. Next to prolonged stability under ambient conditions we show with XRD that the use of an additive, 3-chloropropyl ammonium chloride, influences crystal formation by orienting the crystals. These ~500 nm crystals show individual photoluminescent behavior in thin films and have a longer photoluminescence lifetime at the grain boundaries as compared to the center of the crystal or relative to un-doped materials without the additive made under identical conditions. Charges recombine slower at the edges of the crystals as observed with confocal laser scanning microscopy

scholarly journals Astrogliosis in an Experimental Model of Hypovitaminosis B12: A Cellular Basis of Neurological Disorders due to Cobalamin Deficiency

Cells ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 2261
Author(s):  
Zuzanna Rzepka ◽  
Jakub Rok ◽  
Justyna Kowalska ◽  
Klaudia Banach ◽  
Justyna Magdalena Hermanowicz ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Cobalamin Deficiency ◽  
Confocal Laser ◽  
In Vivo Model ◽  
Cellular Expression ◽  
Wide Range ◽  
Vitro Model

Cobalamin deficiency affects human physiology with sequelae ranging from mild fatigue to severe neuropsychiatric abnormalities. The cellular and molecular aspects of the nervous system disorders associated with hypovitaminosis B12 remain largely unknown. Growing evidence indicates that astrogliosis is an underlying component of a wide range of neuropathologies. Previously, we developed an in vitro model of cobalamin deficiency in normal human astrocytes (NHA) by culturing the cells with c-lactam of hydroxycobalamin (c-lactam OH-Cbl). We revealed a non-apoptotic activation of caspases (3/7, 8, 9) in cobalamin-deficient NHA, which may suggest astrogliosis. The aim of the current study was to experimentally verify this hypothesis. We indicated an increase in the cellular expression of two astrogliosis markers: glial fibrillary acidic protein and vimentin in cobalamin-deficient NHA using Western blot analysis and immunocytochemistry with confocal laser scanning microscopy. In the next step of the study, we revealed c-lactam OH-Cbl as a potential non-toxic vitamin B12 antagonist in an in vivo model using zebrafish embryos. We believe that the presented results will contribute to a better understanding of the cellular mechanism underlying neurologic pathology due to cobalamin deficiency and will serve as a foundation for further studies.

scholarly journals High In Vitro Antibacterial Activity of Pac-525 againstPorphyromonas gingivalisBiofilms Cultured on Titanium

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Ji-yin Li ◽  
Xue-jin Wang ◽  
Li-na Wang ◽  
Xiao-xia Ying ◽  
Xiang Ren ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Pathogenic Bacteria ◽  
Fusobacterium Nucleatum ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Average Cell ◽  
Biofilm Thickness ◽  
Live Bacteria ◽  
In Vitro Antibacterial Activity

In order to investigate the potential of short antimicrobial peptides (AMPs) as alternative antibacterial agents during the treatment of peri-implantitis, the cytotoxic activity of three short AMPs, that is, Pac-525, KSL-W, and KSL, was determined using the MTT assay. The antimicrobial activity of these AMPs, ranging in concentration from 0.0039 mg/mL to 0.5 mg/mL, against the predominant planktonic pathogens, includingStreptococcus sanguis, Fusobacterium nucleatum, andPorphyromonas gingivalis, involved in peri-implantitis was investigated. Furthermore, 2-day-oldP. gingivalisbiofilms cultured on titanium surfaces were treated with Pac-525 and subsequently observed and analysed using confocal laser scanning microscopy (CLSM). The average cell proliferation curve indicated that there was no cytotoxicity due to the three short AMPs. The minimum inhibitory concentration and minimum bactericidal concentration values of Pac-525 were 0.0625 mg/mL and 0.125 mg/mL, respectively, forP. gingivalisand 0.0078 mg/mL and 0.0156 mg/mL, respectively, forF. nucleatum. Using CLSM, we confirmed that compared to 0.1% chlorhexidine, 0.5 mg/mL of Pac-525 caused a significant decrease in biofilm thickness and a decline in the percentage of live bacteria. These data indicate that Pac-525 has unique properties that might make it suitable for the inhibition the growth of pathogenic bacteria around dental implants.

scholarly journals Magnetic poly(ε-caprolactone)/iron-doped hydroxyapatite nanocomposite substrates for advanced bone tissue engineering

2013 ◽  
Vol 10 (80) ◽  
pp. 20120833 ◽  
Author(s):  
A. Gloria ◽  
T. Russo ◽  
U. D'Amora ◽  
S. Zeppetelli ◽  
T. D'Alessandro ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Laser Scanning ◽  
Magnetic Measurements ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Hyperthermia Treatment ◽  
Wide Range ◽  
Iron Doped

In biomedicine, magnetic nanoparticles provide some attractive possibilities because they possess peculiar physical properties that permit their use in a wide range of applications. The concept of magnetic guidance basically spans from drug delivery and hyperthermia treatment of tumours, to tissue engineering, such as magneto-mechanical stimulation/activation of cell constructs and mechanosensitive ion channels, magnetic cell-seeding procedures, and controlled cell proliferation and differentiation. Accordingly, the aim of this study was to develop fully biodegradable and magnetic nanocomposite substrates for bone tissue engineering by embedding iron-doped hydroxyapatite (FeHA) nanoparticles in a poly(ε-caprolactone) (PCL) matrix. X-ray diffraction analyses enabled the demonstration that the phase composition and crystallinity of the magnetic FeHA were not affected by the process used to develop the nanocomposite substrates. The mechanical characterization performed through small punch tests has evidenced that inclusion of 10 per cent by weight of FeHA would represent an effective reinforcement. The inclusion of nanoparticles also improves the hydrophilicity of the substrates as evidenced by the lower values of water contact angle in comparison with those of neat PCL. The results from magnetic measurements confirmed the superparamagnetic character of the nanocomposite substrates, indicated by a very low coercive field, a saturation magnetization strictly proportional to the FeHA content and a strong history dependence in temperature sweeps. Regarding the biological performances, confocal laser scanning microscopy and AlamarBlue assay have provided qualitative and quantitative information on human mesenchymal stem cell adhesion and viability/proliferation, respectively, whereas the obtained ALP/DNA values have shown the ability of the nanocomposite substrates to support osteogenic differentiation.

scholarly journals The Effect of Thermocycling on Interfacial Bonding Stability of Self-Etch Adhesives: OCT Study

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
T. A. Bakhsh ◽  
A. Turkistani
Keyword(s):  
Laser Scanning ◽  
Adhesive System ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Gap Formation ◽  
Swept Source ◽  
Before And After ◽  
One Step ◽  
Self Etch ◽  
Filled Composite

Objective. The aim of this study was to monitor the behavior of interfacial gaps formed under different bonded polymeric restorations before and after thermocycling (TC), using swept-source optical coherence tomography (SS-OCT) and confirming the obtained findings with confocal laser scanning microscopy (CLSM). Materials and Methods. Cylindrical class I cavities were prepared in twenty noncarious human premolar teeth ( 1.5   mm   depth × 3.5   mm   diameter ) and divided randomly into two groups: TS and SN, according to the adhesive system ( n = 10 ). In the TS group, one-step self-etch adhesive Clearfil Tri-S Bond Plus (Kuraray Noritake Dental, Japan) was used, followed by composite restoration using Estelite Sigma Quick (Tokuyama Dental, Japan). In the SN group, the cavities were restored with the two-step self-etch/composite silorane-based resin restoration system (3M ESPE, USA). All specimens were restored in bulk filling technique and cured in accordance with the manufacturers’ instructions. Both groups were imaged under SS-OCT after 24 h and recorded as controls. Then, each group was subjected to thermal challenge using the TC machine (5–55°C) and B-scans were recorded at different TC intervals (2600, 5200, and 10000). In order to confirm the SS-OCT findings, additional specimens were prepared, scanned, and sectioned for CLSM observation. Results. B-scans demonstrated white clusters at the tooth-resin interface that corresponded to the gap location on CLSM images. The TS group showed significantly less gap formation than the SN group before and after TC ( p < 0.001 ). Conclusions. An optimal composite adaptation can be achieved when the bonded restoration comprises a combination of an adhesive containing 10-MDP monomer and a considerable highly filled composite.

scholarly journals Self-Assembly System Based on Cyclodextrin for Targeted Delivery of Cannabidiol

2021 ◽  
Vol 9 ◽  
Author(s):  
Panyong Zhu ◽  
Pin Lv ◽  
Yazhou Zhang ◽  
Rongqiang Liao ◽  
Jing Liu ◽  
...  
Keyword(s):  
Inclusion Complex ◽  
Anticancer Activity ◽  
Targeted Delivery ◽  
Laser Scanning ◽  
Water Solubility ◽  
Cannabis Sativa ◽  
Human Cancer ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Wide Range

Cannabidiol (CBD) is one specific kind of the cannabinoid in Cannabis sativa L with a wide range of pharmacological activities. However, the poor water solubility and specificity of CBD limits its application in pharmaceutical field. For solving these problems, in this work, we successfully prepared a targeted carrier by grafting biotin (BIO) onto ethylenediamine-β-Cyclodextrin (EN-CD) in a single step to generate a functionalized supramolecule, named BIO-CD. Subsequently, an amantadine-conjugated cannabinoids (AD-CBD) was prepared and self-assembled with the BIO-CD. A series of methods were used to characterize the inclusion behavior and physicochemical properties of AD-CBD and BIO-CD. The results showed that AD-CBD entered the cavity of BIO-CD and formed a 1:1 host-guest inclusion complex. MTT assay and confocal laser scanning microscopy (CLSM) revealed that the targeting effect and anticancer activity of AD-CBD/BIO-CD inclusion complex against three human cancer cell lines were higher than BIO-CD, AD-CBD and free CBD. Moreover, the inclusion complex could release drugs under weakly acidic conditions. These results demonstrated that AD-CBD/BIO-CD inclusion complex possess excellent targeted and anticancer activity, which is hopeful to be applied in clinic as a new therapeutic approach.

scholarly journals Cell-to-Cell Signaling in Xylella fastidiosa Suppresses Movement and Xylem Vessel Colonization in Grape

2008 ◽  
Vol 21 (10) ◽  
pp. 1309-1315 ◽  
Author(s):  
Subhadeep Chatterjee ◽  
Karyn L. Newman ◽  
Steven E. Lindow
Keyword(s):  
Cell Signaling ◽  
Type Strain ◽  
Laser Scanning ◽  
Wild Type Strain ◽  
Xylella Fastidiosa ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Deficient Mutant ◽  
Wild Type ◽  
Wide Range

Cell-to-cell signaling mediated by a fatty acid diffusible signaling factor (DSF) is central to the regulation of the virulence of Xylella fastidiosa. DSF production by X. fastidiosa is dependent on rpfF and, although required for insect colonization, appears to reduce its virulence to grape. To understand what aspects of colonization of grape are controlled by DSF in X. fastidiosa and, thus, those factors that contribute to virulence, we assessed the colonization of grape by a green fluorescent protein–marked rpfF-deficient mutant. The rpfF-deficient mutant was detected at a greater distance from the point of inoculation than the wild-type strain at a given sampling time, and also attained a population size that was up to 100-fold larger than that of the wild-type strain at a given distance from the point of inoculation. Confocal laser-scanning microscopy revealed that approximately 10-fold more vessels in petioles of symptomatic leaves harbored at least some cells of either the wild type or rpfF mutant when compared with asymptomatic leaves and, thus, that disease symptoms were associated with the extent of vessel colonization. Importantly, the rpfF mutant colonized approximately threefold more vessels than the wild-type strain. Although a wide range of colony sizes were observed in vessels colonized by both the wild type and rpfF mutant, the proportion of colonized vessels harboring large numbers of cells was significantly higher in plants inoculated with the rpfF mutant than with the wild-type strain. These studies indicated that the hypervirulence phenotype of the rpfF mutant is due to both a more extensive spread of the pathogen to xylem vessels and unrestrained multiplication within vessels leading to blockage. These results suggest that movement and multiplication of X. fastidiosa in plants are linked, perhaps because cell wall degradation products are a major source of nutrients. Thus, DSF-mediated cell-to-cell signaling, which restricts movement and colonization of X. fastidiosa, may be an adaptation to endophytic growth of the pathogen that prevents the excessive growth of cells in vessels.

Surface Characterization Using Wavelet Theory and Confocal Laser Scanning Microscopy

2005 ◽  
Vol 127 (2) ◽  
pp. 394-404 ◽  
Author(s):  
Chengqing Yuan ◽  
Zhongxiao Peng ◽  
Xinping Yan
Keyword(s):  
Surface Roughness ◽  
Confocal Laser Scanning Microscopy ◽  
Laser Scanning ◽  
Surface Characterization ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Scanning Microscopy ◽  
Confocal Laser ◽  
Wavelet Theory ◽  
Wide Range

Surface characterization, particularly roughness analysis, is very important for a wide range of applications including wear assessment. This paper proposes a set of methods and techniques to acquire appropriate images using confocal laser scanning microscopy, to separate roughness, waviness, and form using wavelet theory, and to characterize surface roughness for engineering surfaces and surfaces of small particles. Two application examples on engineering surfaces and wear particles have been presented in the paper to demonstrate that the method developed in this study can be used to measure surface roughness reliably and precisely. A guide on how to determine the iris size, step size, and objective lens has been scientifically provided according to theoretical analysis and experimental results.

scholarly journals Morphology of powerful suction organs from blepharicerid larvae living in raging torrents

BMC Zoology ◽  
2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Victor Kang ◽  
Richard Johnston ◽  
Thomas van de Kamp ◽  
Tomáš Faragó ◽  
Walter Federle
Keyword(s):  
Laser Scanning ◽  
Close Contact ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Wide Range ◽  
Flow Speeds ◽  
Micro Tomography ◽  
Structural Adaptations ◽  
Attachment Devices

Abstract Background Suction organs provide powerful yet dynamic attachments for many aquatic animals, including octopus, squid, remora, and clingfish. While the functional morphology of suction organs from some cephalopods and fishes has been investigated in detail, there are only few studies on such attachment devices in insects. Here we characterise the morphology and ultrastructure of the suction attachment organs of net-winged midge larvae (genus Liponeura; Diptera: Blephariceridae) – aquatic insects that live on rocks in rapid alpine waterways where flow speeds can reach 3 m s− 1 – using scanning electron microscopy, confocal laser scanning microscopy, and X-ray computed micro-tomography (micro-CT). Furthermore, we study the function of these organs in vivo using interference reflection microscopy. Results We identified structural adaptations important for the function of the suction attachment organs in L. cinerascens and L. cordata. First, a dense array of spine-like microtrichia covering each suction disc comes into contact with the substrate upon attachment, analogous to hairy structures on suction organs from octopus, clingfish, and remora fish. These spine-like microtrichia may contribute to the seal and provide increased shear force resistance in high-drag environments. Second, specialised rim microtrichia at the suction disc periphery were found to form a continuous ring in close contact and may serve as a seal on a variety of surfaces. Third, a V-shaped cut on the suction disc (“V-notch“) is actively opened via two cuticular apodemes inserting on its flanks. The apodemes are attached to dedicated V-notch opening muscles, thereby providing a unique detachment mechanism. The complex cuticular design of the suction organs, along with specialised muscles that attach to them, allows blepharicerid larvae to generate powerful attachments which can withstand strong hydrodynamic forces and quickly detach for locomotion. Conclusion The suction organs from Liponeura are underwater attachment devices specialised for resisting extremely fast flows. Structural adaptations from these suction organs could translate into future bioinspired attachment systems that perform well on a wide range of surfaces.

scholarly journals Enhanced Grain-boundary Emission Lifetime and Additive Induced Crystal Orientation in One-Step Spin-Coated Mixed Cationic (FA/MA) Lead Perovskite Thin Films Stabilized by Zinc Iodide Doping

2017 ◽  
Author(s):  
Loreta A. Muscarella ◽  
Dina Petrova ◽  
Rebecca Jorge Cervasio ◽  
Aram Farawar ◽  
Olivier Lugier ◽  
...  
Keyword(s):  
Thin Films ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Crystal Formation ◽  
Ambient Conditions ◽  
Emission Lifetime ◽  
Photoluminescence Lifetime ◽  
One Step ◽  
Zinc Iodide

Mixed cationic lead perovskites containing formamidinium and methylammonium can be stabilized by incorporating ZnI<sub>2 </sub>as an “internal desiccant”. Next to prolonged stability under ambient conditions we show with XRD that the use of an additive, 3-chloropropyl ammonium chloride, influences crystal formation by orienting the crystals. These ~500 nm crystals show individual photoluminescent behavior in thin films and have a longer photoluminescence lifetime at the grain boundaries as compared to the center of the crystal or relative to un-doped materials without the additive made under identical conditions. Charges recombine slower at the edges of the crystals as observed with confocal laser scanning microscopy. The material can also be prepared as a black precursor powder by a solid-solid reaction under ambient conditions.

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