Directional rolling of positively charged nanoparticles along a flexibility gradient on long DNA molecules

Soft Matter ◽  
2018 ◽  
Vol 14 (5) ◽  
pp. 817-825 ◽  
Author(s):  
Suehyun Park ◽  
Heesun Joo ◽  
Jun Soo Kim
Keyword(s):  
Dna Molecules ◽  
Dna Flexibility ◽  
Charged Nanoparticles ◽  
Positively Charged

Directed rolling of a nanoparticle along a gradient of local DNA flexibility.

scholarly journals Layer-by-Layer 3D Constructs of Fibroblasts in Hydrogel for Examining Transdermal Penetration Capability of Nanoparticles

2016 ◽  
Vol 22 (4) ◽  
pp. 447-453 ◽  
Author(s):  
Xiaochun Hou ◽  
Shiying Liu ◽  
Min Wang ◽  
Christian Wiraja ◽  
Wei Huang ◽  
...  
Keyword(s):  
Transdermal Delivery ◽  
Three Dimensional ◽  
Layer By Layer ◽  
Surface Charges ◽  
Skin Model ◽  
Collagen Hydrogel ◽  
Penetration Ability ◽  
Charged Nanoparticles ◽  
Transdermal Penetration ◽  
Positively Charged

Nanoparticles are emerging transdermal delivery systems. Their size and surface properties determine their efficacy and efficiency to penetrate through the skin layers. This work utilizes three-dimensional (3D) bioprinting technology to generate a simplified artificial skin model to rapidly screen nanoparticles for their transdermal penetration ability. Specifically, this model is built through layer-by-layer alternate printing of blank collagen hydrogel and fibroblasts. Through controlling valve on-time, the spacing between printing lines could be accurately tuned, which could enable modulation of cell infiltration in the future. To confirm the effectiveness of this platform, a 3D construct with one layer of fibroblasts sandwiched between two layers of collagen hydrogel is used to screen silica nanoparticles with different surface charges for their penetration ability, with positively charged nanoparticles demonstrating deeper penetration, consistent with the observation from an existing study involving living skin tissue.

Strategy for improved analysis of peptides by surface-enhanced Raman spectroscopy (SERS) involving positively charged nanoparticles

2008 ◽  
Vol 39 (5) ◽  
pp. 611-617 ◽  
Author(s):  
Sarah M. Ngola ◽  
Jingwu Zhang ◽  
Breeana L. Mitchell ◽  
Narayan Sundararajan
Keyword(s):  
Raman Spectroscopy ◽  
Surface Enhanced Raman Spectroscopy ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Charged Nanoparticles ◽  
Positively Charged

scholarly journals Improvement of stem cell-derived exosome release efficiency by surface modified nanoparticles

2020 ◽  
Author(s):  
Dong Jun Park ◽  
Wan Su Yun ◽  
Woo Cheol Kim ◽  
Jeong-Eun Park ◽  
Su Hoon Lee ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stromal Cells ◽  
Molecular Mechanisms ◽  
Genetic Factors ◽  
Autophagosome Formation ◽  
Quantification Limit ◽  
Charged Nanoparticles ◽  
Surface Modified ◽  
Surface Modified Nanoparticles ◽  
Positively Charged

Abstract Background: Mesenchymal stem cells (MSCs) are pluripotent stromal cells that release extracellular vesicles (EVs). EVs contain various growth factors and antioxidants that can positively affect the surrounding cells. Nanoscale MSC-derived EVs, such as exosomes, have been developed as bio-stable nano-type materials. However, some issues such as low yield and difficulty in quantification limit their use. We hypothesized that enhancing exosome production using nanoparticles would stimulate intracellular molecules. Results: Our aim in this study was to elucidate the molecular mechanisms of exosome generation by comparing the internalization of surface-modified, positively charged nanoparticles and exosome generation from MSCs. We determined that Rab7, which is located in the multiple vesicle body and autolysosomal membrane, was increased upon exosome expression and was associated with autophagosome formation. Conclusions: Nanoparticles may migrate to lysosomes during treatment. Simultaneously, intracellular exosome-forming factors can be stimulated during endosomal maturation. MSC-derived exosomes using nanoparticles may increase exosome yield and enable the discovery of nanoparticle-induced genetic factors.

scholarly journals Improvement of stem cell-derived exosome release efficiency by surface-modified nanoparticles

2020 ◽  
Author(s):  
Dong Jun Park ◽  
Wan Su Yun ◽  
Woo Cheol Kim ◽  
Jeong-Eun Park ◽  
Su Hoon Lee ◽  
...  
Keyword(s):  
Stromal Cells ◽  
Molecular Mechanisms ◽  
Genetic Factors ◽  
Autophagosome Formation ◽  
Related Factors ◽  
Quantification Limit ◽  
Charged Nanoparticles ◽  
Surface Modified ◽  
Surface Modified Nanoparticles ◽  
Positively Charged

Abstract Background: Mesenchymal stem cells (MSCs) are pluripotent stromal cells that release extracellular vesicles (EVs). EVs contain various growth factors and antioxidants that can positively affect the surrounding cells. Nanoscale MSC-derived EVs, such as exosomes, have been developed as bio-stable nano-type materials. However, some issues, such as low yield and difficulty in quantification, limit their use. We hypothesized that enhancing exosome production using nanoparticles would stimulate the release of intracellular molecules. Results: The aim of this study was to elucidate the molecular mechanisms of exosome generation by comparing the internalization of surface-modified, positively charged nanoparticles and exosome generation from MSCs. We determined that Rab7, a late endosome and auto-phagosome marker, was increased upon exosome expression and was associated with autophagosome formation. Conclusions: It was concluded that the nanoparticles we developed were transported to the lysosome by clathrin-mediated endocytosis. additionally, entered nanoparticles stimulated that autophagy related factors to release exosome from the MSC. MSC-derived exosomes using nanoparticles may increase exosome yield and enable the discovery of nanoparticle-induced genetic factors.

Positively Charged Magnetic Nanoparticles for Capture of Circulating Tumor Cells from Clinical Blood Samples

Nano LIFE ◽  
2020 ◽  
Vol 10 (03) ◽  
pp. 1971001 ◽  
Author(s):  
Shengming Wu ◽  
Yilong Wang ◽  
Donglu Shi
Keyword(s):  
Magnetic Nanoparticles ◽  
Cancer Cells ◽  
Cancer Patients ◽  
Tumor Cells ◽  
Circulating Tumor Cells ◽  
Cancer Cell ◽  
Detection Sensitivity ◽  
Blood Samples ◽  
Charged Nanoparticles ◽  
Positively Charged

Isolation of circulating tumor cells (CTCs) from cancer patients is of high value for disease monitoring and metastasis diagnosis. Although many new detection methods have emerged in recent years, the detection of CTCs is a current challenge due to lack of specific and sensitive markers. In our previous work, cancer cell surfaces, from over 20 cancer cell lines, have been shown to be negatively-charged regardless of their phenotype by using electrically-charged nanoparticles as a probe. The strong electrostatic interaction between the negative cancer cells and positively charged nanoparticles can well remain in a physiological liquid environment in the presence of serum proteins, enabling effective binding between them. As a result, the cancer cells can be magnetically separated by employing an external magnet. In this technical report, we present preliminary results on the investigation of CTC isolation from both mimetic and clinical blood samples. We show high CTC detection sensitivity by the positively-charged magnetic nanoparticles (PMNs) even at the original concentration of 10 cells per mL mimetic blood sample. The CTCs in the peripheral blood of colorectal cancer patients were isolated and identified by cellular morphology and immunofluorescence staining.

Anodic Electrophoretic Deposition of TiO2 Nanoparticles Synthesized Using Sol Gel Method

2013 ◽  
Vol 832 ◽  
pp. 633-638
Author(s):  
Khatijah Aisha Yaacob ◽  
David Jason Riley
Keyword(s):  
Electrophoretic Deposition ◽  
Deposition Time ◽  
Anatase Phase ◽  
Sol Gel ◽  
Particle Diameter ◽  
Deposition Process ◽  
Titanium Isopropoxide ◽  
Solid Loading ◽  
Charged Nanoparticles ◽  
Positively Charged

Many researches on electrophoretic deposition of TiO2 nanoparticles (NPs) use commercial TiO2 nanoparticles from Degussa. TiO2 from Degussa is not use in this research because in order to make the TiO2 nanoparticle electronically charged and move under an applied constant voltage, a small amount of iodine and acetylacetone needs to be added to the suspension. It is suggested that the H+ ions generated by the reaction is absorbed on the suspended particles making them positively charged. For anodic EPD, negatively charged nanoparticles are required. In this research TiO2 nanoparticles were prepared by adding 1 ml of titanium isopropoxide dilute with 1 ml ethanol to 10 ml DI water and stirrer under 0°C for 4 hr. As prepared TiO2 nanoparticle were centrifuged at 5500 rpm for 10 min to isolate the particles from the solution. Then the TiO2 nanoparticles were resuspended in ethanol or water. TiO2 nanoparticle with particle diameter of 4.66 nm and anatase phase were produced. Important electrophoretic deposition process parameters, such as apparent pH of the TiO2 NPs, applied voltage, deposition time and solid loading, were studied during electrophoretic deposition of TiO2 nanoparticles.

Paramagnetic nanoparticles as nuclear magnetic resonance contrast agents in sandstone: Importance of nanofluid-rock interactions

2016 ◽  
Vol 4 (2) ◽  
pp. SF55-SF65 ◽  
Author(s):  
Chunxiao Zhu ◽  
Hugh Daigle ◽  
Steven L. Bryant
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Relaxation Time ◽  
Magnetic Resonance ◽  
Pore Size ◽  
Pore Surface ◽  
Mineral Surface ◽  
Surface Relaxivity ◽  
Charged Nanoparticles ◽  
Positively Charged ◽  
Zirconia Nanoparticles

Nuclear magnetic resonance has been applied in well logging to investigate pore size distribution with high resolution and accuracy based on the relaxation time distribution. However, due to the heterogeneity of natural rock, pore surface relaxivity, which links relaxation time and pore size, varies within the pore system. To analyze and alter pore surface relaxivity, we saturated Boise sandstone cores with positively charged zirconia nanoparticle dispersions in which nanoparticles can be adsorbed onto the sandstone pore wall, while negatively charged zirconia nanoparticles dispersions were used as a control group to provide the baseline of nanoparticle retention due to nonelectrostatic attraction. We have performed core flushing with deionized water, pure acid, and alkali with different pH values; compared properties of zirconia nanoparticles before and after exposure to Boise sandstone; analyzed the portion of zirconia nanoparticles retained in the rock; altered pore surface relaxivity; and linked the adsorbed nanoparticle concentration on the pore surface to the modified surface relaxivity. Our work has indicated that after two pore volumes of core flooding, there was approximately 1% of negatively charged nanoparticles trapped in the Boise sandstone core, whereas approximately 8%–11% of positively charged nanoparticles was retained in the Boise sandstone cores. Our results indicated that besides van der Waals attraction, electrostatic attraction was the driving force for retention of nanoparticles with a positive surface charge in sandstone cores. The attachment of nanoparticles onto sandstone surfaces changed the mineral surface relaxivity. Exposure to acidic or strong alkaline conditions increased the Boise sandstone surface relaxivity. After contact with Boise sandstone, the nanoparticles themselves exhibited increased relaxivity due to interactions between nanoparticles dispersion and mineral surface under different pH conditions.

scholarly journals Influence of Surface Charge on the Functional Properties of Silica Nanoparticles and Cellular Toxicity

2020 ◽  
Vol 9 (3) ◽  
pp. 1225-1238
Keyword(s):  
Surface Charge ◽  
Silica Nanoparticles ◽  
Sio2 Nanoparticles ◽  
Carboxyl Groups ◽  
Raw 264.7 ◽  
Sem Images ◽  
Raw 264.7 Macrophages ◽  
Charged Nanoparticles ◽  
The Difference ◽  
Positively Charged

The effect of silica nanoparticles with a different surface charge on the cell viability of Caco-2 and RAW 264.7 cell lines was studied. Silica nanoparticles with narrow size distribution were prepared by Stobers method. These silica nanoparticles surface charge was varied from highly positive to highly negative, were single functionalized by APTES and multi functionalized by cysteine for amine and carboxyl groups. All other properties of the nanoparticles were kept constant. The unfunctionalized nanoparticles were used as control. Fourier Transform Infrared spectroscopy (FTIR) confirmed the presence of amine and carboxyl groups present on the surface of silica nanoparticles. The zeta potential measurements confirmed the successful modification of surface charge of silica nanoparticles in water. SEM images showed that the negatively charged, positively charged, and unfunctionalized nanoparticles with similar size and shape. MTT assay results indicated that the toxicity of SiO2 was cell type-dependent. CaCo-2 cells were highly resistant to nanoparticle treatment whereas RAW 264.7 (macrophages) predominantly charge dependent. The difference in toxicity could be attributed to the difference in the physiological function of each cell line. Among the three kinds of nanoparticles (negative, positive, and untreated), positively charged nanoparticles showed higher toxicity, which might be due to the attractive interaction between the negatively charged cell membrane and positively charged SiO2 nanoparticles.

The effect of surface charge on oral absorption of polymeric nanoparticles

2018 ◽  
Vol 6 (3) ◽  
pp. 642-650 ◽  
Author(s):  
Xiao-Jiao Du ◽  
Ji-Long Wang ◽  
Shoaib Iqbal ◽  
Hong-Jun Li ◽  
Zhi-Ting Cao ◽  
...  
Keyword(s):  
Small Intestine ◽  
Surface Charge ◽  
Oral Bioavailability ◽  
Oral Absorption ◽  
Polymeric Nanoparticles ◽  
Charged Nanoparticles ◽  
Positively Charged ◽  
Effect Of Surface

Positively charged nanoparticles showed a favorable distribution in the small intestine, and significantly improved oral bioavailability.

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