Showing posts with label nanoparticles. Show all posts
Showing posts with label nanoparticles. Show all posts

Saturday, 17 August 2013

Fighting cancer with nanoparticles

Main Category: Cancer / Oncology
Also Included In: Immune System / Vaccines
Article Date: 17 Aug 2013 - 0:00 PDT Current ratings for:
Fighting cancer with nanoparticles
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Researchers at the University of Georgia are developing a new treatment technique that uses nanoparticles to reprogram immune cells so they are able to recognize and attack cancer. The findings were published recently in the early online edition of ACS Nano.

The human body operates under a constant state of martial law. Chief among the enforcers charged with maintaining order is the immune system, a complex network that seeks out and destroys the hordes of invading bacteria and viruses that threaten the organic society as it goes about its work.

The immune system is good at its job, but it's not perfect. Most cancerous cells, for example, are able to avoid detection by the immune system because they so closely resemble normal cells, leaving the cancerous cells free to multiply and grow into life-threatening tumors while the body's only protectors remain unaware.

Shanta Dhar and her colleagues are giving the immune system a boost through their research.

"What we are working on is specifically geared toward breast cancer," said Dhar, the study's co-author and an assistant professor of chemistry in the UGA Franklin College of Arts and Sciences. "Our paper reports for the first time that we can stimulate the immune system against breast cancer cells using mitochondria-targeted nanoparticles and light using a novel pathway."

In their experiments, Dhar and her colleagues exposed cancer cells in a petri dish to specially designed nanoparticles 1,000 times finer than the width of a human hair. The nanoparticles invade the cell and penetrate the mitochondria - the organelles responsible for producing the energy a cell needs to grow and replicate.

They then activated the nanoparticles inside the cancer cells by exposing them to a tissue-penetrating long wavelength laser light. Once activated, the nanoparticles disrupt the cancer cell's normal processes, eventually leading to its death.

The dead cancer cells were collected and exposed to dendritic cells, one of the core components of the human immune system. What the researchers saw was remarkable.

"We are able to potentially overcome some of the traditional drawbacks to today's dendritic cell immunotherapy," said Sean Marrache, a graduate student in Dhar's lab. "By targeting nanoparticles to the mitochondria of cancer cells and exposing dendritic cells to these activated cancer cells, we found that the dendritic cells produced a high concentration of chemical signals that they normally don't produce, and these signals have traditionally been integral to producing effective immune stimulation."

Dhar added that the "dendritic cells recognized the cancer as something foreign and began to produce high levels of interferon-gamma, which alerts the rest of the immune system to a foreign presence and signals it to attack. We basically used the cancer against itself."

She cautions that the results are preliminary, and the approach works only with certain forms of breast cancer. But if researchers can refine the process, this technology may one day serve as the foundation for a new cancer vaccine used to both prevent and treat disease.

"We particularly hope this technique could help patients with advanced metastatic disease that has spread to other parts of the body," said Dhar, who also is a member of the UGA Nanoscale Science and Engineering Center, Cancer Center and Center for Drug Discovery.

If the process were to become a treatment, doctors could biopsy a tumor from the patient and kill the cancerous cells with nanoparticles. They could then produce activated dendritic cells in bulk quantities in the lab under controlled conditions before the cells were injected into the patient.

Once in the bloodstream, the newly activated cells would alert the immune system to the cancer's presence and destroy it.

"These are the things we can now do with nanotechnology," Dhar said. "If we can refine the process further, we may be able to use similar techniques against other forms of cancer as well."

Article adapted by Medical News Today from original press release. Click 'references' tab above for source.
Visit our cancer / oncology section for the latest news on this subject.

Besides Dhar and Marrache, other UGA researchers on the project were Smanla Tundup and Donald A. Harn. The work was supported by a startup grant from the National Institutes of Health (P30 GM 092378) to UGA, by the UGA Office of the Vice President for Research to Dhar and by a grant from the National Institutes of Health (NIH AI056484) to Harn.

Ex Vivo Programming of Dendritic Cells by Mitochondria-Targeted Nanoparticles to Produce Interferon-Gamma for Cancer Immunotherapy

ACS Nano, DOI: 10.1021/nn403158n

University of Georgia

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Monday, 5 August 2013

Test strips bearing gold nano-particles as sensor elements can detect numerous proteins simultaneously

Main Category: Medical Devices / Diagnostics
Also Included In: Biology / Biochemistry
Article Date: 03 Aug 2013 - 0:00 PDT Current ratings for:
Test strips bearing gold nano-particles as sensor elements can detect numerous proteins simultaneously
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Chemists at Johannes Gutenberg University Mainz (JGU) have developed a new method for parallel protein analysis that is, in principle, capable of identifying hundreds or even thousands of different proteins. It could be used to detect the presence of viruses and identify their type in tiny samples. At the same time, it is very cost-effective and quick. "We see possible applications of this technique in medicine, where it could be used, for example, for the rapid diagnosis of a wide range of diseases. It would be almost as easy to use as a pregnancy test strip," said Professor Carsten Sonnichsen of the Institute of Physical Chemistry. The test involves placing a tiny drop of blood, saliva, or other bodily fluid on a small test strip, which is then placed in a device developed at the JGU Institute of Physical Chemistry. This device is able to identify the specific proteins in the fluid and thus allows to quickly and reliably differentiate between harmless microorganisms and dangerous pathogens.

In order to detect the many different substances present in a small sample, the sensors need to be as tiny as possible, preferably the size of nano-particles. Sonnichsen's team of scientists have designed a sensor no larger than the head of a pin but capable of performing a hundred different individual tests on a surface that is only of one-tenth of a square millimeter in area. The 'test strips' consist of glass capillary tubes that have gold nano-particles as sensor elements on their internal surfaces. "We first prepare our nano-particles using short DNA strands, each of which binds to a specific type of protein," explained Janak Prasad, who developed the functionalization method. When a protein docks with one of these special DNA strands, called aptamers, the corresponding nano-particle changes its color. The color changes can be detected with the aid of a spectrometer. For this purpose, the capillary tubes are placed under a microscope designed, constructed, and provided with the necessary software by the Mainz-based team of chemists.

"We demonstrate a new approach for a multiplexed assay that detects multiple proteins simultaneously by letting a fluid flow past the randomly positioned gold nano-rods," explained Christina Rosman, first author of the study. The team from JGU's Institute of Physical Chemistry used four different target proteins to demonstrate the viability of the new concept, its ability to detect concentrations in the nanomolar range, and the possibility to recycle the sensors for more than one analysis. "We see the potential to extend our method to the simultaneous detection of hundreds or even thousands of different target substances," assert the authors in their article published in the June 2013 issue of the journal Nano Letters. Low-cost serial production of the sensors is feasible if advanced nano-fabrication methods such as nano-printing or optical trapping are used.

There are manifold possible applications of a test for multiple targets in a single procedure. The low-cost sensors could be directly used by physicians in their practices in order to detect and discriminate various types of flu viruses with which their patients could be infected. In addition, the technique would also be suitable for detecting the presence of toxins in the environment or in food, particularly in liquids such as milk or baby food, or the presence of doping or other illicit drugs.

Article adapted by Medical News Today from original press release. Click 'references' tab above for source.
Visit our medical devices / diagnostics section for the latest news on this subject.

Support for the research on this novel multiplexed protein sensor was provided by the Graduate School of Excellence 'Materials Science in Mainz' (MAINZ) and the European Research Council (ERC) 'Single Sense' project.

Johannes Gutenberg Universitaet Mainz

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Johannes Gutenberg Universitaet Mainz. "Test strips bearing gold nano-particles as sensor elements can detect numerous proteins simultaneously." Medical News Today. MediLexicon, Intl., 3 Aug. 2013. Web.
3 Aug. 2013. APA

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'Test strips bearing gold nano-particles as sensor elements can detect numerous proteins simultaneously'

Please note that we publish your name, but we do not publish your email address. It is only used to let you know when your message is published. We do not use it for any other purpose. Please see our privacy policy for more information.

If you write about specific medications or operations, please do not name health care professionals by name.

All opinions are moderated before being included (to stop spam). We reserve the right to amend opinions where we deem necessary.

Contact Our News Editors

For any corrections of factual information, or to contact the editors please use our feedback form.

Please send any medical news or health news press releases to:

Note: Any medical information published on this website is not intended as a substitute for informed medical advice and you should not take any action before consulting with a health care professional. For more information, please read our terms and conditions.



View the original article here