88 research outputs found
Towards a system for tracking drug delivery using frequency excited gold nanoparticles
Nanoparticle-based drugs are rapidly evolving to treat different conditions and have considerable potential. A new system based on the combination of electrical impedance tomography (EIT) imaging and a power amplifier with a RF coil has been developed to study the effect of gold nanoparticles (AuNPs) when excited in the MHz frequency range. We show that samples including AuNPs have a temperature increase of 1−1.5 °C due to the presence of RF excitation at 13.56 MHz which provides a higher rate of change for solutions without AuNPs. They also show more than a 50% increase in conductivity in difference imaging as the result of this excitation. The change for samples without AuNPs is 40%
Towards a System for Tracking Drug Delivery Using Frequency Excited Gold Nanoparticles
Nanoparticle-based drugs are rapidly evolving to treat different conditions and have
considerable potential. A new system based on the combination of electrical impedance tomography
(EIT) imaging and a power amplifier with a RF coil has been developed to study the effect of gold
nanoparticles (AuNPs) when excited in the MHz frequency range. We show that samples including
AuNPs have a temperature increase of 1–1.5 ◦C due to the presence of RF excitation at 13.56 MHz
which provides a higher rate of change for solutions without AuNPs. They also show more than a
50% increase in conductivity in difference imaging as the result of this excitation. The change for
samples without AuNPs is 40%
Nanoparticle electrical impedance tomography
We have developed a new approach to imaging with electrical impedance tomography (EIT) using gold nanoparticles (AuNPs) to enhance impedance changes at targeted tissue sites. This is achieved using radio frequency (RF) to heat nanoparticles while applying EIT imaging. The initial results using 5-nm citrate coated AuNPs show that heating can enhance the impedance in a solution containing AuNPs due to the application of an RF field at 2.60 GHz
Concentração e especificidade de lipase de Aspergillus niger obtida por fermentação no estado sólido (FES).
Estudo das características físicos-químicas de lipase de Aspergillus niger visando sua aplicação em alimentos.
Locating functionalized gold nanoparticles using electrical impedance tomography
Objective: An imaging device to locate functionalised nanoparticles, whereby therapeutic agents are transported from the site of administration specifically to diseased tissues, remains a challenge for pharmaceutical research. Here, we show a new method based on electrical impedance tomography (EIT) to provide images of the location of gold nanoparticles (GNPs) and the excitation of GNPs with radio frequencies (RF) to change impedance permitting an estimation of their location in cell models
Methods: We have created an imaging system using quantum cluster GNPs as contrast agent, activated with RF fields to heat the functionalized GNPs, which causes a change in impedance in the surrounding region. This change is then identified with EIT.
Results: Images of impedance changes of around 80±4% are obtained for a sample of citrate stabilized GNPs in a solution of phosphate-buffered saline. A second quantification was carried out using colorectal cancer cells incubated with culture media, and the internalization of GNPs into the colorectal cancer cells was undertaken to compare them with the EIT images. When the cells were incubated with functionalised GNPs, the change was more apparent, approximately 40±2%. This change was reflected in the EIT image as the cell area was more clearly identifiable from the rest of the area.
Significance: EIT can be used as a new method to locate functionalized GNPs in human cells and help in the development of GNP-based drugs in humans to improve their efficacy in the future
Estudo da estabilidade a temperatura, pH e a estocagem, de lipase produzida por Aspergillus niger em fermentação semi-sólida.
Locating Functionalized Gold Nanoparticles Using Electrical Impedance Tomography
Abstract Objective: An imaging device to locate functionalized nanoparticles, whereby therapeutic agents are transported from the site of administration specifically to diseased tissues, remains a challenge for pharmaceutical research. Here, we show a new method based on electrical impedance tomography (EIT) to provide images of the location of gold nanoparticles (GNPs) and the excitation of GNPs with radio frequencies (RF) to change impedance permitting an estimation of their location in cell models Methods: We have created an imaging system using quantum cluster GNPs as a contrast agent, activated with RF fields to heat the functionalized GNPs, which causes a change in impedance in the surrounding region. This change is then identified with EIT. Results: Images of impedance changes of around 804% are obtained for a sample of citrate stabilized GNPs in a solution of phosphate-buffered saline. A second quantification was carried out using colorectal cancer cells incubated with culture media, and the internalization of GNPs into the colorectal cancer cells was undertaken to compare them with the EIT images. When the cells were incubated with functionalized GNPs, the change was more apparent, approximately 402%. This change was reflected in the EIT image as the cell area was more clearly identifiable from the rest of the area. Significance: EIT can be used as a new method to locate functionalized GNPs in human cells and help in the development of GNP-based drugs in humans to improve their efficacy in the future
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