Thiol-Functionalized IGEPAL® Surfactants as Novel Fluorescent Ligands for the Silica Coating of Gold Nanoparticles

2015 ◽  
Vol 56 (4) ◽  
pp. 249-256 ◽  
Author(s):  
Helena Gavilán-Rubio ◽  
João Paulo Coelho ◽  
Guillermo González-Rubio ◽  
Gloria Tardajos ◽  
José Osío Barcina ◽  
...  
2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Inese Kokina ◽  
Inese Jahundoviča ◽  
Ilona Mickeviča ◽  
Marija Jermaļonoka ◽  
Jānis Strautiņš ◽  
...  

Development of methods for direct delivery of different bioactive substances into the cell is a promising and intensively approached area of research. It has become a subject of serious research for multidisciplinary team of scientists working in such areas as physics, biology, and biotechnology. Plant calluses were grown on medium supplemented with different nanoparticles to be used as a model for biotechnological research. Gold nanoparticles with mesoporous silica coating were used as hormone carriers, since they possess many of critical properties required for cellular transportation instrument. Some of those properties are great biocompatibility and controlled release of carried molecules. Significant changes in hormones common impact were detected. The great increase in ploidy numbers, embryogenesis, induction, and methylation level was observed when compared to the “conventional” methods of targeted hormones delivery that embrace usage of Au nanoparticles as a main hormone carrier. The authors suppose the research under consideration can provide a new pathway to the design of a novel targeted plant hormone and bioactive substances carrier.


2016 ◽  
Vol 8 (1) ◽  
Author(s):  
Jyoti Verma ◽  
Henk A. Van Veen ◽  
Sumit Lal ◽  
Cornelis J.F. Van Noorden

AbstractNanoparticles with coating entrapping a chemotherapeutic drug for delivery have not been tested for their cytotoxic effects in in-vitro glioblastoma cell cultures to increase treatment efficacy. Therefore, we synthesized silica-coated gold nanorods and gold nanospheres that were loaded with doxorubicin or temozolomide. The morphology of the nanoparticles was characterized using transmission electron microscopy (TEM), the molecular structure was characterized using infrared spectroscopy and in vitro efficacy was determined using glioblastoma cell cultures. TEM analysis showed that gold nanorods had a length of 49–65 nm and a diameter of 8.5–14 nm whereas gold nanospheres had a diameter of 9.5–37 nm. Infrared spectroscopy of doxorubicin and temozolomide and the silica coating revealed molecular fingerprints such as bending, stretching and vibrations of chemical bonds that confirmed the presence of silica coating and drug loading of the gold nanoparticles. In the biological assessment of the effects of drug-loaded gold nanoparticles on primary glioblastoma cell cultures, cytotoxicity, viability and the ratio of cyototoxicity and viability were used as parameters to analyze the effects on the cells of drug delivery via gold nanoparticles on the cells. Our data suggest that doxorubicin in the concentration range of 0.12–3.16 μM when delivered using both gold nanorods and nanospheres induced a 3.8–5.5-fold increased cytotoxicity in comparison to direct delivery. Temozolomide in the concentration range of 4.6–115 μM when delivered by either type of gold nanoparticles induced a 2–4-fold increased cytotoxicity in comparison to direct delivery. Nanospheres were more effective in delivery and cytotoxicity of doxorubicin and temozolomide to glioblastoma cells than gold nanorods. Our data suggest that gold nanoparticles and in particular gold nanospheres are more effective in delivery of doxorubicin and temozolomide to primary glioblastoma cells in culture than direct delivery.


RSC Advances ◽  
2015 ◽  
Vol 5 (24) ◽  
pp. 18977-18982 ◽  
Author(s):  
Hien Duy Mai ◽  
Kiouk Seo ◽  
Soon Choi ◽  
Hyojong Yoo

Raspberry-like gold nanoparticles (Au RLNPs) show high catalytic activities in the reduction of 4-nitrophenol and ethanol electrooxidation. To improve the stability and applicability of Au RLNPs, silica-coated Au RLNPs were successfully synthesized.


Author(s):  
J. W. Mellowes ◽  
C. M. Chun ◽  
I. A. Aksay

Mullite (3Al2O32SiO2) can be fabricated by transient viscous sintering using composite particles which consist of inner cores of a-alumina and outer coatings of amorphous silica. Powder compacts prepared with these particles are sintered to almost full density at relatively low temperatures (~1300°C) and converted to dense, fine-grained mullite at higher temperatures (>1500°C) by reaction between the alumina core and the silica coating. In order to achieve complete mullitization, optimal conditions for coating alumina particles with amorphous silica must be achieved. Formation of amorphous silica can occur in solution (homogeneous nucleation) or on the surface of alumina (heterogeneous nucleation) depending on the degree of supersaturation of the solvent in which the particles are immersed. Successful coating of silica on alumina occurs when heterogeneous nucleation is promoted and homogeneous nucleation is suppressed. Therefore, one key to successful coating is an understanding of the factors such as pH and concentration that control silica nucleation in aqueous solutions. In the current work, we use TEM to determine the optimal conditions of this processing.


2013 ◽  
Vol 51 (01) ◽  
Author(s):  
N Fekete-Drimusz ◽  
J de la Roche ◽  
F Vondran ◽  
CL Sajti ◽  
MP Manns ◽  
...  

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