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.

scholarly journals Superparamagnetic Iron Oxide Nanoparticles Coated with Galactose-Carrying Polymer for Hepatocyte Targeting

2007 ◽  
Vol 2007 ◽  
pp. 1-9 ◽  
Author(s):  
Mi Kyong Yoo ◽  
In Yong Kim ◽  
Eun Mi Kim ◽  
Hwan-Jeong Jeong ◽  
Chang-Moon Lee ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Iron Oxide Nanoparticles ◽  
Laser Scanning ◽  
Superparamagnetic Iron Oxide ◽  
Laser Scanning Microscopy ◽  
Superparamagnetic Iron Oxide Nanoparticles ◽  
Mri Contrast Agent ◽  
Confocal Laser ◽  
Oxide Nanoparticles ◽  
Specific Accumulation

Our goal is to develop the functionalized superparamagnetic iron oxide nanoparticles (SPIONs) demonstrating the capacities to be delivered in liver specifically and to be dispersed in physiological environment stably. For this purpose, SPIONs were coated with polyvinylbenzyl-O-β-D-galactopyranosyl-D-gluconamide (PVLA) having galactose moieties to be recognized by asialoglycoprotein receptors (ASGP-R) on hepatocytes. For use as a control, we also prepared SPIONs coordinated with 2-pyrrolidone. The sizes, size distribution, structure, and coating of the nanoparticles were characterized by transmission electron microscopy (TEM), electrophoretic light scattering spectrophotometer (ELS), X-ray diffractometer (XRD), and Fourier transform infrared (FT-IR), respectively. Intracellular uptake of the PVLA-coated SPIONs was visualized by confocal laser scanning microscopy, and their hepatocyte-specific delivery was also investigated through magnetic resonance (MR) images of rat liver. MRI experimental results indicated that the PVLA-coated SPIONs possess the more specific accumulation property in liver compared with control, which suggests their potential utility as liver-targeting MRI contrast agent.

scholarly journals Lyophilized Iron Oxide Nanoparticles Encapsulated in Amphotericin B: A Novel Targeted Nano Drug Delivery System for the Treatment of Systemic Fungal Infections

Pharmaceutics ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 247
Author(s):  
Pavan Balabathula ◽  
Sarah Garland Whaley ◽  
Dileep R. Janagam ◽  
Nivesh K. Mittal ◽  
Bivash Mandal ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Drug Release ◽  
Amphotericin B ◽  
Iron Oxide Nanoparticles ◽  
Delivery System ◽  
Fungal Infections ◽  
Drug Loading ◽  
Laser Scanning Microscopy ◽  
Oxide Nanoparticles ◽  
Burst Release

We formulated and tested a targeted nanodrug delivery system to help treat life-threatening invasive fungal infections, such as cryptococcal meningitis. Various designs of iron oxide nanoparticles (IONP) (34–40 nm) coated with bovine serum albumin and coated and targeted with amphotericin B (AMB-IONP), were formulated by applying a layer-by-layer approach. The nanoparticles were monodispersed and spherical in shape, and the lead formulation was found to be in an optimum range for nanomedicine with size (≤36 nm), zeta potential (−20 mV), and poly dispersity index (≤0.2), and the drug loading was 13.6 ± 6.9 µg of AMB/mg of IONP. The drug release profile indicated a burst release of up to 3 h, followed by a sustained drug release of up to 72 h. The lead showed a time-dependent cellular uptake in C. albicans and C. glabrata clinical isolates, and exhibited an improved efficacy (16–25-fold) over a marketed conventional AMB-deoxycholate product in susceptibility testing. Intracellular trafficking of AMB-IONP by TEM and confocal laser scanning microscopy confirmed the successful delivery of the AMB payload at and/or inside the fungal cells leading to potential therapeutic advantages over the AMB-deoxycholate product. A short-term stability study at 5 °C and 25 °C for up to two months showed that the lyophilized form was stable.

scholarly journals In vivo MRI detection of intraplaque macrophages with biocompatible silica-coated iron oxide nanoparticles in murine atherosclerosis

2021 ◽  
Vol 19 ◽  
pp. 228080002110147
Author(s):  
Chan Woo Kim ◽  
Byung-Hee Hwang ◽  
Hyeyoung Moon ◽  
Jongeun Kang ◽  
Eun-Hye Park ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Iron Oxide Nanoparticles ◽  
Atherosclerotic Plaque ◽  
Immunohistochemical Staining ◽  
Multimodal Imaging ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Oxide Nanoparticles ◽  
Atherosclerotic Plaques

Identification of a vulnerable atherosclerotic plaque before rupture is an unmet clinical need. Integrating nanomedicine with multimodal imaging has the potential to precisely detect biological processes in atherosclerosis. We synthesized silica-coated iron oxide nanoparticles (SIONs) coated with rhodamine B isothiocyanate and polyethylene glycol and investigated their feasibility in the detection of macrophages in inflamed atherosclerotic plaques of apolipoprotein E-deficient (ApoE−/−) mice via magnetic resonance (MR) and fluorescence reflectance (FR) imaging. In vitro cellular uptake of SIONs was assessed in macrophages using confocal laser scanning microscopy (CLSM). In vivo MR imaging was performed 24 h after SION injection via the tail vein in 26-week-old ApoE−/− mice fed a high-cholesterol diet (HCD). We also performed FR imaging of the extracted aortas from four different mice: two normal-diet-fed C57BL/6 mice injected with saline or 10 mg/kg SIONs and two HCD-fed ApoE−/− mice injected with 5 or 10 mg/kg SIONs. The harvested aortas were cryosectioned and stained with immunohistochemical staining. The CLSM images at 24 h after incubation showed efficient uptake of SIONs by macrophages, with no evidence of cytotoxicity. The in vivo and ex vivo MR and FR images demonstrated SION deposition in the atheroma. Upon immunohistochemical staining of the aorta, CLSM images revealed colocalization of macrophages and SIONs in the atherosclerotic plaque. These results demonstrate that polyethylene glycosylated SIONs could be a highly effective method to identify macrophage activity in atherosclerotic plaques as a multimodal imaging agent.

scholarly journals Involvement of two uptake mechanisms of gold and iron oxide nanoparticles in a co-exposure scenario using mouse macrophages

2017 ◽  
Vol 8 ◽  
pp. 2396-2409 ◽  
Author(s):  
Dimitri Vanhecke ◽  
Dagmar A Kuhn ◽  
Dorleta Jimenez de Aberasturi ◽  
Sandor Balog ◽  
Ana Milosevic ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Iron Oxide ◽  
Iron Oxide Nanoparticles ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Emission Spectrometry ◽  
Oxide Nanoparticles ◽  
Full Potential ◽  
Toxicological Studies ◽  
Uptake Mechanisms

Little is known about the simultaneous uptake of different engineered nanoparticle types, as it can be expected in our daily life. In order to test such co-exposure effects, murine macrophages (J774A.1 cell line) were incubated with gold (AuNPs) and iron oxide nanoparticles (FeO x NPs) either alone or combined. Environmental scanning electron microscopy revealed that single NPs of both types bound within minutes on the cell surface but with a distinctive difference between FeO x NPs and AuNPs. Uptake analysis studies based on laser scanning microscopy, transmission electron microscopy, and inductively coupled plasma optical emission spectrometry revealed intracellular appearance of both NP types in all exposure scenarios and a time-dependent increase. This increase was higher for both AuNPs and FeO x NPs during co-exposure. Cells treated with endocytotic inhibitors recovered after co-exposure, which additionally hinted that two uptake mechanisms are involved. Cross-talk between uptake pathways is relevant for toxicological studies: Co-exposure acts as an uptake accelerant. If the goal is to maximize the cellular uptake, e.g., for the delivery of pharmaceutical agents, this can be beneficial. However, co-exposure should also be taken into account in the case of risk assessment of occupational settings. The demonstration of co-exposure-invoked pathway interactions reveals that synergetic nanoparticle effects, either positive or negative, must be considered for nanotechnology and nanomedicine in particular to develop to its full potential.

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.

Antibiofilm activity of antifungal drugs, including the novel drug olorofim, against Lomentospora prolificans

2020 ◽  
Author(s):  
Lisa Kirchhoff ◽  
Silke Dittmer ◽  
Ann-Kathrin Weisner ◽  
Jan Buer ◽  
Peter-Michael Rath ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Antifungal Agents ◽  
Fungal Infections ◽  
Pathogenic Fungus ◽  
Antifungal Drugs ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Antibiofilm Activity

Abstract Objectives Patients with immunodeficiency or cystic fibrosis frequently suffer from respiratory fungal infections. In particular, biofilm-associated fungi cause refractory infection manifestations, linked to increased resistance to anti-infective agents. One emerging filamentous fungus is Lomentospora prolificans. Here, the biofilm-formation capabilities of L. prolificans isolates were investigated and the susceptibility of biofilms to various antifungal agents was analysed. Methods Biofilm formation of L. prolificans (n = 11) was estimated by crystal violet stain and antibiofilm activity was additionally determined via detection of metabolically active biofilm using an XTT assay. Amphotericin B, micafungin, voriconazole and olorofim were compared with regard to their antibiofilm effects when added prior to adhesion, after adhesion and on mature and preformed fungal biofilms. Imaging via confocal laser scanning microscopy was carried out to demonstrate the effect of drug treatment on the fungal biofilm. Results Antibiofilm activities of the tested antifungal agents were shown to be most effective on adherent cells whilst mature biofilm was the most resistant. The most promising antibiofilm effects were detected with voriconazole and olorofim. Olorofim showed an average minimum biofilm eradication concentration (MBEC) of 0.06 mg/L, when added prior to and after adhesion. The MBECs of voriconazole were ≤4 mg/L. On mature biofilm the MBECs of olorofim and voriconazole were higher than the previously determined MICs against planktonic cultures. In contrast, amphotericin B and especially micafungin did not exhibit sufficient antibiofilm activity against L. prolificans. Conclusions To our knowledge, this is the first study demonstrating the antibiofilm potential of olorofim against the human pathogenic fungus L. prolificans.

Micro-trabeculae, macro-plaques or mini-basement membranes in human term fetal membranes?

1993 ◽  
Vol 342 (1300) ◽  
pp. 121-136 ◽  
Keyword(s):  
Extracellular Matrix ◽  
Laser Scanning ◽  
Thick Layer ◽  
Basement Membranes ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Fetal Membranes ◽  
Epithelial Basement Membrane ◽  
Type Vii Collagen ◽  
Spongy Layer

Immunocytochemical confocal laser scanning microscopy and ultrastructural analysis, including immunoelectron microscopy, reveals the distribution of structures in human term amniochorion similar in some respects to basement membranes but with unusually restricted dimensions. On the basis of their immunoreactivity, these trabecular structures, found on the fibroblast layer side of the spongy layer of human term amniochorion and adjacent reticular layer, have been shown to contain type IV collagen, laminin, and nidogen. The origin of these components may be from primitive epithelial structures which pumped fluid into the lakes that eventually coalesced to form the extraem bryonic coelom separating the extraem bryonic somatic mesoderm from the extraem bryonic splanchnic mesoderm. Such a theory of their origin might link them with the mysterious ‘cellular layer’, a single-cell-thick layer of cells which is usually no longer present in fetal membranes at term. The similarity in composition but not in size of these structures to anchoring plaques for type VII collagen is possible support for the view that these structures are integrators of extracellular matrix polymeric proteins. The ‘pseudobasement’ membrane associated with the trophoblast layer, on investigation, appears to be typical by six criteria. ‘Coiled’ fibrous structures in the extracellular matrix of the spongy layer may aid adjustments under tension at this shear surface by a detachable ‘Velcro’ or ‘two spring’ fastening system. The coils are rich in fibronectin. The suggestion is made that the compact layer is a giant lamina reticularis associated with the amniotic epithelial basement membrane.

scholarly journals Autolysin-Independent DNA Release inStreptococcus pneumoniae in vitroBiofilms

2018 ◽  
Author(s):  
Mirian Domenech ◽  
Ernesto García
Keyword(s):  
Extracellular Matrix ◽  
Quorum Sensing ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Extracellular Dna ◽  
Confocal Laser ◽  
Lytic Enzymes ◽  
Microbial Biofilms ◽  
Dna Release

ABSTRACTBiofilms are defined as layers of cells of microorganisms adhered to the surface of a substrate and embedded in an extracellular matrix and provide an appropriate environment for increased genetic exchange. Extracellular DNA (eDNA) is an essential component of the extracellular matrix of microbial biofilms, but the pathway(s) responsible for DNA release are largely unknown. Autolysis (either spontaneous or phage-induced) has been proposed the major event leading to the appearance of eDNA. The ‘suicidal tendency’ ofStreptococcus pneumoniaeis well-known, with lysis mainly caused by the triggering of LytA, the major autolytic amidase. However, the LytC lysozyme and CbpD (a possible murein hydrolase) have also been shown involved. The present work examines the relationship between eDNA, autolysins, and the formation and maintenance ofin vitropneumococcal biofilms, via fluorescent labelling combined with confocal laser scanning microscopy, plus genetic transformation experiments. Bacterial DNA release mechanisms other than those entailing lytic enzymes were shown to be involved by demonstrating that horizontal gene transfer in biofilms takes place even in the absence of detectable autolytic activity. It had been previously suggested that the quorum sensing systems ComABCDE and LuxS/AI-2 are involved in the production of eDNA as a response to the accumulation of quorum sensing signals, although our immunofluorescence results do not support this hypothesis. Evidence that the release of DNA is somehow linked to the production of extracellular vesicles byS. pneumoniaeis provided.

scholarly journals Targeting and Cellular Trafficking of Magnetic Nanoparticles for Prostate Cancer Imaging

2007 ◽  
Vol 6 (4) ◽  
pp. 7290.2007.00025 ◽  
Author(s):  
Rita E. Serda ◽  
Natalie L. Adolphi ◽  
Marco Bisoffi ◽  
Laurel O. Sillerud
Keyword(s):  
Prostate Cancer ◽  
Iron Oxide ◽  
Cancer Cells ◽  
Iron Oxide Nanoparticles ◽  
Magnetic Particles ◽  
Metastatic Cancer ◽  
Confocal Laser ◽  
Oxide Nanoparticles ◽  
Prostate Cancer Cells ◽  
Mr Images

Antibody-conjugated iron oxide nanoparticles offer a specific and sensitive tool to enhance magnetic resonance (MR) images of both local and metastatic cancer. Prostate-specific membrane antigen (PSMA) is predominantly expressed on the neovasculature of solid tumors and on the surface of prostate cells, with enhanced expression following androgen deprivation therapy. Biotinylated anti-PSMA antibody was conjugated to streptavidin-labeled iron oxide nanoparticles and used in MR imaging and confocal laser scanning microscopic imaging studies using LNCaP prostate cancer cells. Labeled iron oxide nanoparticles are internalized by receptor-mediated endocytosis, which involves the formation of clathrin-coated vesicles. Endocytosed particles are not targeted to the Golgi apparatus for recycling but instead accumulate within lysosomes. In T1-weighted MR images, the signal enhancement owing to the magnetic particles was greater for cells with magnetic particles bound to the cell surface than for cells that internalized the particles. However, the location of the particles (surface vs internal) did not significantly alter their effect on T2-weighted images. Our findings indicate that targeting prostate cancer cells using PSMA offers a specific and sensitive technique for enhancing MR images.

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