Visualizing cell‐laden fibrin‐based hydrogels using cryogenic scanning electron microscopy and confocal microscopy

2019 ◽  
Vol 13 (4) ◽  
pp. 587-598 ◽  
Author(s):  
Maya Schnabel‐Lubovsky ◽  
Olga Kossover ◽  
Sonia Melino ◽  
Francesca Nanni ◽  
Yeshayahu Talmon ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Confocal Microscopy ◽  
Cryogenic Scanning Electron Microscopy ◽  
Scanning Electron

Cryogenic-scanning electron microscopy as a technique to image sol-to-gel transformation in chelated alkoxide systems

1996 ◽  
Vol 22 (2) ◽  
pp. 155-159 ◽  
Author(s):  
Manoj M. Haridas ◽  
Ashok Menon ◽  
Nitin Goyal ◽  
Sanjay Chandran ◽  
Jayesh R. Bellare
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cryogenic Scanning Electron Microscopy ◽  
Scanning Electron

Melt electro written three-dimensional scaffolds engineered as oral microcosm models-an in vitro study.

2020 ◽  
Author(s):  
Srinivas Ramachandra ◽  
Abdulla Abdal-hay ◽  
Pingping Han ◽  
Ryan Lee ◽  
Saso Ivanovski
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Confocal Microscopy ◽  
Pore Size ◽  
Next Generation ◽  
16S Sequencing ◽  
3 Dimensional ◽  
Wide Range ◽  
Scanning Electron ◽  
Medical Grade

<p><strong>Introduction</strong>: Biofilms are 3-dimensional (3D) aggregates of microorganisms that are associated with a wide range of diseases. Although there have been several studies investigating biofilm formation on two-dimensional substrates, the use of 3D substrates may result in more representative and clinically relevant models. Accordingly, the aim of this study was to compare the growth of biofilms in the 3D substrates against biofilms grown in 2D substrates.<br /><strong>Material and Methods:</strong> Two grams of medical grade polycaprolactone (PCL) were loaded into a plastic Luer-lock 3 ml syringe and a 23G needle was used as a spinneret. The syringe was placed in a melt electro-writing (MEW) device to obtain fine fibers under controlled parameters. The 3-dimensional MEW PCL scaffolds were manufactured and characterised with an overall thickness of ~ 0.8 mm, with ~ 15 μm diameter fibers and ordered pore sizes of either 100 or 250 µm. PCL films employed as 2D substrates were manufactured by dissolving 10 gms of PCL in 100 ml chloroform and stirred for 3 h to obtain a transparent solution. Then, the solution was cast in glass petri dishes and dried to remove all organic solvents. In addition, commercial hydroxyapatite discs were also used as 2D controls. Unstimulated saliva from six healthy donors (gingival health) were used to grow biofilms. The formed biofilms were assessed at day 4, day 7 and day 10 using crystal violet assay, confocal microscopy, scanning electron microscopy and next-generation 16s sequencing.<br /><strong>Results:</strong> The results demonstrates that 3D PCL scaffolds dramatically enhanced biofilm biomass and thickness growth compared to that of the 2D controls. Confocal microscopy of biofilms at day 4 stained with SYTO 9 and propidium iodide showed thickness of biofilms in 2D substrates were 39 µm and 81µm for hydroxyapatite discs and PCL films, respectively. Biofilms in 3D substrates were 250 µm and 338 µm for MEW PCL 100µm pore size and MEW PCL 250 µm pore size, respectively. Similar results were noticed at day 7 and day 10. Scanning electron microscopy showed biofilm bridges formed over the fibers of the MEW scaffolds. Pilot trials of next generation sequencing detected similar taxa in biofilms formed in 3D scaffolds compared to that of 2D substrates.<br /><strong>Discussion:</strong> We have successfully investigated a 3D biofilm growth model using 3D medical grade PCL scaffolds. Thicker biofilms can be conveniently grown using this inexpensive static model. This will facilitate 3D microbial community studies that are more clinically relevant and improve our understanding of biofilm-associated disease processes.</p> <p> </p>

scholarly journals A Comparison of Iron Oxide Particles and Silica Particles for Tracking Organ Recellularization

2018 ◽  
Vol 17 ◽  
pp. 153601211878732 ◽  
Author(s):  
Joseph E. Kobes ◽  
George I. Georgiev ◽  
Anthony V. Louis ◽  
Isen A. Calderon ◽  
Eriko S. Yoshimaru ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Iron Oxide ◽  
Detection Limit ◽  
Confocal Microscopy ◽  
Ultrasound Imaging ◽  
Silica Particles ◽  
Iron Oxide Particles ◽  
Oxide Particles ◽  
Scanning Electron

Reseeding of decellularized organ scaffolds with a patient’s own cells has promise for eliminating graft versus host disease. This study investigated whether ultrasound imaging or magnetic resonance imaging (MRI) can track the reseeding of murine liver scaffolds with silica-labeled or iron-labeled liver hepatocytes. Mesoporous silica particles were created using the Stöber method, loaded with Alexa Flour 647 fluorophore, and conjugated with protamine sulfate, glutamine, and glycine. Fluorescent iron oxide particles were obtained from a commercial source. Liver cells from donor mice were loaded with the silica particles or iron oxide particles. Donor livers were decellularized and reperfused with silica-labeled or iron-labeled cells. The reseeded livers were longitudinally analyzed with ultrasound imaging and MRI. Liver biopsies were imaged with confocal microscopy and scanning electron microscopy. Ultrasound imaging had a detection limit of 0.28 mg/mL, while MRI had a lower detection limit of 0.08 mg/mL based on particle weight. The silica-loaded cells proliferated at a slower rate compared to iron-loaded cells. Ultrasound imaging, MRI, and confocal microscopy underestimated cell numbers relative to scanning electron microscopy. Ultrasound imaging had the greatest underestimation due to coarse resolution compared to the other imaging modalities. Despite this underestimation, both ultrasound imaging and MRI successfully tracked the longitudinal recellularization of liver scaffolds.

scholarly journals Micropipes in SiC Single Crystal Observed by Molten KOH Etching

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5890
Author(s):  
Hejing Wang ◽  
Jinying Yu ◽  
Guojie Hu ◽  
Yan Peng ◽  
Xuejian Xie ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Confocal Microscopy ◽  
Polymorphic Transformation ◽  
Laser Confocal Microscopy ◽  
Etch Pits ◽  
Screw Dislocations ◽  
Etching Behavior ◽  
Koh Etching ◽  
Scanning Electron

Micropipe, a “killer” defect in SiC crystals, severely hampers the outstanding performance of SiC-based devices. In this paper, the etching behavior of micropipes in 4H-SiC and 6H-SiC wafers was studied using the molten KOH etching method. The spectra of 4H-SiC and 6H-SiC crystals containing micropipes were examined using Raman scattering. A new Raman peak accompanying micropipes located near −784 cm−1 was observed, which may have been induced by polymorphic transformation during the etching process in the area of micropipe etch pits. This feature may provide a new way to distinguish micropipes from other defects. In addition, the preferable etching conditions for distinguishing micropipes from threading screw dislocations (TSDs) was determined using laser confocal microscopy, scanning electron microscopy (SEM) and optical microscopy. Meanwhile, the micropipe etching pits were classified into two types based on their morphology and formation mechanism.

scholarly journals How ticks get under your skin: insertion mechanics of the feeding apparatus of Ixodes ricinus ticks

2013 ◽  
Vol 280 (1773) ◽  
pp. 20131758 ◽  
Author(s):  
Dania Richter ◽  
Franz-Rainer Matuschka ◽  
Andrew Spielman ◽  
L. Mahadevan
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Lyme Disease ◽  
Confocal Microscopy ◽  
Ixodes Ricinus ◽  
Feeding Apparatus ◽  
Structural Dynamic ◽  
Dynamic Mechanical ◽  
Ixodes Ricinus Ticks ◽  
Scanning Electron

The tick Ixodes ricinus uses its mouthparts to penetrate the skin of its host and to remain attached for about a week, during which time Lyme disease spirochaetes may pass from the tick to the host. To understand how the tick achieves both tasks, penetration and attachment, with the same set of implements, we recorded the insertion events by cinematography, interpreted the mouthparts’ function by scanning electron microscopy and identified their points of articulation by confocal microscopy. Our structural dynamic observations suggest that the process of insertion and attachment occurs via a ratchet-like mechanism with two distinct stages. Initially, the two telescoping chelicerae pierce the skin and, by moving alternately, generate a toehold. Subsequently, a breaststroke-like motion, effected by simultaneous flexure and retraction of both chelicerae, pulls in the barbed hypostome. This combination of a flexible, dynamic mechanical ratchet and a static holdfast thus allows the tick to solve the problem of how to penetrate skin and also remain stuck for long periods of time.

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