scholarly journals 3249 Defining the Extracellular Vesicle Content of Interstitial Fluid for Blood-Free Diagnostics; Extraction Methods and Initial Characterization

2019 ◽  
Vol 3 (s1) ◽  
pp. 7-7
Author(s):  
Justin Baca Robert Taylor ◽  
Srinivasa Rao Gadam ◽  
Lauren Perez

OBJECTIVES/SPECIFIC AIMS: Recent advances in microneedle technology have enabled practical, in vivo dermal interstitial fluid (ISF) sampling. These minimally-invasive techniques allow for collection of ISF without damage to adjacent tissues and do not rely on blister formation. Initial reports of extracellular vesicle (EV) isolation from dermal ISF and paired blood samples suggest that EVs may be more abundant in ISF. Analysis of ISF-derived EVs may allow for more detailed study of intercellular communication at the tissue level, particularly in acute inflammatory conditions. The objective of this study is to describe the isolation and initial characterization of interstitial fluid-derived exosomes. METHODS/STUDY POPULATION: We apply electron microscopy, nanoparticle tracking analysis (NTA), immuochemical, and sequencing methods to describe and distinguish the EV content of interstitial fluid. We include apparently healthy adult human subjects with no active skin disease. We also study immunocompetent, CD-hairless rats to demonstrate the generalizability of the methods. RESULTS/ANTICIPATED RESULTS: We successfully isolated EVs from human and rat interstitial fluid using commercially available precipitation methods. The EVs were initially characterized using UV/Vis spectroscopy, electron microscopy, and NTA. While the study is ongoing, initial results suggest that the concentration and size distribution of EVs differs significantly between blood fractions and ISF. Further immunochemical and sequencing characterization is ongoing. DISCUSSION/SIGNIFICANCE OF IMPACT: We present here the initial characterization of EVs isolated from dermal interstitial fluid. This appears to be the first report of EV characterization using ISF collection methods that do not perturb adjacent tissues (such as with blister or microdialysis methods). The present study lays a foundation for further examination of ISF-derived EVs in acute inflammatory disease such as cellulitis or infectious neuritis. This may enable minimally invasive diagnostics and new research tools to understand intercellular communication in living organisms with increased spatial and temporal resolution.

2020 ◽  
Vol 10 ◽  
pp. 184798042096688
Author(s):  
Galo Cárdenas-Triviño ◽  
Sergio Triviño-Matus

Metal colloids in 2-mercaptoethanol using nanoparticles (NPs) of iron (Fe), cobalt (Co), and nickel (Ni) were prepared by chemical liquid deposition method. Transmission electron microscopy, electron diffraction, UV-VIS spectroscopy, and scanning electron microscopy with electron dispersive X-ray spectroscopy characterized the resulting colloidal dispersions. The NPs exhibited sizes with ranges from 9.8 nm for Fe, 3.7 nm for Co, and 7.2 nm for Ni. The electron diffraction shows the presence of the metals in its elemental state Fe (0), Co (0), and Ni (0) and also some compounds FeO (OH), CoCo2S4, and NiNi2S4.


2014 ◽  
Vol 661 ◽  
pp. 8-13 ◽  
Author(s):  
Intan Syaffinazzilla Zaine ◽  
N.A.M. Napiah ◽  
Azmi Mohamad Yusof ◽  
A.N. Alias ◽  
A.M.M. Ali ◽  
...  

The MWCNTs was functionalized by refluxing commercial MWCNTs (a-MWCNTs) in concentrated HNO3/H2SO4 (3:1 v/v) at 100°C for 6 hours. The dispersion of a-MWCNTs and functionalized MWCNTs (f-MWCNTs) were observed after 1 hour sonication in ethanol. Both samples were characterized by UV-vis spectroscopy for dispersion behavior. The dried f-MWCNTs and a-MWCNTs were characterized by Raman spectroscopy to estimate the defect level. The morphology of the samples were analyzed by Transmission Electron Microscopy (TEM). The f-MWCNTs was well dispersed in ethanol within 2 weeks of observations period. The colloidal stability of a-MWCNTs was low as it was easily sediment after 24 hours. The UV-vis spectra of f-MWCNTs show maximum absorbance at 250 nm meanwhile no absorbance was observed for a-MWCNTs. Analysis from Raman spectrum shows that the f-MWCNTs have relative intensity of 1.101 which is higher than a-MWCNTs that have relative intensity of 0.935. The image from TEM revealed that the f-MWCNTs have structural defects and the absence of amorphous carbon on sidewall meanwhile the a-MWCNTs indicate otherwise.


2020 ◽  
Vol 142 (6) ◽  
Author(s):  
Daisuke Yamada ◽  
Alperen Değirmenci ◽  
Robert D. Howe

Abstract To characterize the dynamics of internal soft organs and external anatomical structures, this paper presents a system that combines medical ultrasound imaging with an optical tracker and a vertical exciter that imparts whole-body vibrations on seated subjects. The spatial and temporal accuracy of the system was validated using a phantom with calibrated internal structures, resulting in 0.224 mm maximum root-mean-square (r.m.s.) position error and 13 ms maximum synchronization error between sensors. In addition to the dynamics of the head and sternum, stomach dynamics were characterized by extracting the centroid of the stomach from the ultrasound images. The system was used to characterize the subject-specific body dynamics as well as the intrasubject variabilities caused by excitation pattern (frequency up-sweep, down-sweep, and white noise, 1–10 Hz), excitation amplitude (1 and 2 m/s2 r.m.s.), seat compliance (rigid and soft), and stomach filling (empty and 500 mL water). Human subjects experiments (n = 3) yielded preliminary results for the frequency response of the head, sternum, and stomach. The method presented here provides the first detailed in vivo characterization of internal and external human body dynamics. Tissue dynamics characterized by the system can inform design of vehicle structures and adaptive control of seat and suspension systems, as well as validate finite element models for predicting passenger comfort in the early stages of vehicle design.


2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Yann Benureau ◽  
Eliana Moreira Tavares ◽  
Ali-Akbar Muhammad ◽  
Sonia Baconnais ◽  
Eric Le Cam ◽  
...  

Abstract DNA intermediate structures are formed in all major pathways of DNA metabolism. Transmission electron microscopy (TEM) is a tool of choice to study their choreography and has led to major advances in the understanding of these mechanisms, particularly those of homologous recombination (HR) and replication. In this article, we describe specific TEM procedures dedicated to the structural characterization of DNA intermediates formed during these processes. These particular DNA species contain single-stranded DNA regions and/or branched structures, which require controlling both the DNA molecules spreading and their staining for subsequent visualization using dark-field imaging mode. Combining BAC (benzyl dimethyl alkyl ammonium chloride) film hyperphase with positive staining and dark-field TEM allows characterizing synthetic DNA substrates, joint molecules formed during not only in vitro assays mimicking HR, but also in vivo DNA intermediates.


2017 ◽  
Vol 263 ◽  
pp. 165-169
Author(s):  
Silvia Chowdhury ◽  
Faridah Yusof ◽  
Nadzril Sulaiman ◽  
Mohammad Omer Faruck

In this article, we have studied the process of silver nanoparticles (AgNPs) aggregation and to stop aggregation 0.3% Polyvinylpyrrolidone (PVP) was used. Aggregation study carried out via UV-vis spectroscopy and it is reported that the absorption spectrum of spherical silver nanoparticles were found a maximum peak at 420 nm wavelength. Furthermore, Transmission Electron Microscopy (TEM) were used to characterized the size and shape of AgNPs, where the average particle size is around 10 to 25 nm in diameter and the AgNPs shape is spherical. Next, Dynamic Light Scattering (DLS) were used, owing to observed size distribution and self-correlation of AgNPs.


2014 ◽  
Vol 975 ◽  
pp. 233-237
Author(s):  
Joelma C. S. Breve ◽  
Dayse I. dos Santos

Nanostructured composites based on titanium dioxide have been studied in order to improve optical and photo-catalytic properties, as well as their performance in gas sensors. In this work, titanium and tin dioxides were simultaneously synthesized by the polyol method resulting in TiO2 platelet coated with SnO2 nanoparticles as was observed by scanning electron microscopy. The thermal analysis showed that the combined synthesis promotes more easily the crystallization of the TiO2 rutile phase. The composite obtained after heat treatment at 500 °C showed to be formed of almost only rutile phases of both oxides. The optical properties analyzed by UV-Vis spectroscopy showed that the combined oxides have higher absorbance, which reinforces a model found in the literature based on the flow of photo-generated electrons to the conduction band of SnO2 delaying the recombination of charges.


2021 ◽  
Author(s):  
Govindaraju K ◽  
K. Vijai Anand ◽  
S. Muthamilselvan ◽  
M. Kannan ◽  
M. Elanchezhiyan

Abstract In this study, a simple environmental benign approach have been adopted for the preparation of highly luminescent (blue emitting) water soluble carbon nano-dots using Pongammia pinnata (Pp) leaves via hydrothermal technique. The prepared Pp-carbon nano- dots were characterized using UV-vis spectroscopy, fluorescence spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM) and dynamic light scattering (DLS) measurements. The Pp-carbon nano-dots are spherical in shape with an average size of 32 nm.


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