Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New light-emitting biomaterial could improve tumor imaging

12.08.2009
A new material developed at the University of Virginia – an oxygen nanosensor that couples a light-emitting dye with a biopolymer – simplifies the imaging of oxygen-deficient regions of tumors. Such tumors are associated with increased cancer aggressiveness and are particularly difficult to treat.

Oxygen nanosensors are powerful new research tools that one day may also be used for the diagnosis and detection of diseases and for planning treatment strategies.

The new material is based on poly(lactic acid), a biorenewable, biodegradable polymer that is safe for the body and the environment, and is easy and inexpensive to fabricate in many forms, including films, fibers and nanoparticles. It is useful for medical research as well as environmental research, sustainable design and green products, too.

The versatile sensor material is the result of research combining green chemistry with nanotechnology, and is reported in the current online edition of the journal Nature Materials.

Chemists at the University of Virginia developed the material and consulted with cancer researchers at the U.Va. Cancer Center and Duke University Medical Center to determine possible applications.

Guoqing Zhang, a U.Va. chemistry doctoral candidate, working with Cassandra Fraser, a U.Va. chemistry professor, synthesized the new material by combining a corn-based biopolymer with a dye that is both fluorescent and phosphorescent. The phosphorescence appears as a long-lived afterglow that is only evident under low oxygen or oxygen-free conditions.

Zhang devised a method to adjust the relative intensities of short-lived blue fluorescence and long-lived yellow phosphorescence, ultimately creating a calibrated colorful glow that allows visualization of even minute levels of oxygen. The biomaterial displays its oxygen-sensitive phosphorescence at room or body temperature, making it ideal for use in tissues.

"We were amazed at how easy the material was to synthesize and fabricate as films and nanoparticles, and how useful it is for measuring low oxygen concentrations," Fraser said.

"It is based on a bio-friendly material," added Zhang. "It is safe for the body and the environment, and so we realized it could have applications not just for medical research and developing improved disease treatments, but also for new sustainable technologies."

Cancer researchers at Duke quickly realized that the new material could be particularly useful for real-time and extended-time spatial mapping of oxygen levels in tumors. This is important because a lack of sufficient oxygen in tumors – called "hypoxia" – is a major source of resistance to radiation and chemotherapy treatment, and promotes a greater degree of malignancy.

"We have found that these nanoparticles were directly applicable to our existing tumor models," said Greg Palmer, assistant professor of radiation oncology at Duke University Medical Center. "This technology will enable us to better characterize the influence of tumor hypoxia on tumor growth and treatment response."

Researchers and clinicians have long sought effective ways to locate and map low-oxygen areas in the body to better understand normal and disease processes. Presently, there are no simple, easy or inexpensive methods, preclinical or clinical, for generating oxygen maps of tumors and surrounding tissues with good spatial and temporal resolution.

"The method developed here holds great promise for being able to perform measurements of tumor hypoxia cost-effectively," said study co-author Mark Dewhirst, a professor of radiation oncology, pathology and biomedical engineering at Duke. "This kind of tool could greatly increase our knowledge about methods to eliminate tumor hypoxia, which could lead to more effective treatments."

"Tumors that have insufficient oxygen tend to be more likely to spread from the primary site to other parts of the body," added Michael Weber, director of U.Va.'s Cancer Center. "Despite the overall importance of tumor hypoxia, it is very difficult to measure directly and most methods that are available are very expensive."

The new material currently is being used in preclinical studies to gain insight into cancer biology and treatment response, which could be useful for drug development and testing.

"This technology enables entirely new insights to be obtained, allowing imaging of tumor hypoxia on the scale of tumor cells and small blood vessels," Palmer said.

Eventually the material could be used as an injectable nanosensor, potentially providing continual data on oxygen levels, biological processes and therapy responsiveness.

Hypoxia also is linked to cardiovascular disease, stroke and diabetes, so the material developed by Zhang and Fraser could have applications in several areas of medicine.

Applications for the light-emitting biomaterial beyond medicine include molecular probes for cell biology, imaging agents for visualizing fluid and aerodynamics, and oxygen sensors for food and drug packaging, tamper resistant seals, and environmental monitoring, such as measuring oxygen levels in bodies of water.

The research is funded by the U.S. National Science Foundation, the U.S. Department of Defense, U.S. National Institutes of Health, the James and Rebecca Craig Foundation, through the U.Va. Cancer Center, and the U.Va. NanoSTAR Institute.

Contact information for the researchers involved:

Cassandra Fraser
U.Va. researcher
434-924-7998
fraser@virginia.edu
Guoqing Zhang
U.Va. researcher
434-924-7998
gzhang@virginia.edu
Mark Dewhirst
Duke researcher
919-684-4180
linda.rogers@duke.edu
Gregory Palmer
Duke researcher
919-684-3907
greg.palmer@duke.edu

Fariss Samarrai | EurekAlert!
Further information:
http://www.virginia.edu

More articles from Studies and Analyses:

nachricht Drone vs. truck deliveries: Which create less carbon pollution?
31.05.2017 | University of Washington

nachricht New study: How does Europe become a leading player for software and IT services?
03.04.2017 | Fraunhofer-Institut für System- und Innovationsforschung (ISI)

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>