Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Nano-thermometer takes temperature inside cells

23.08.2019

Rice University chemistry lab uses fluorescence of molecular motors to sense conditions

How do you know a cell has a fever? Take its temperature.


Rice University chemists modified BODIPY molecules to serve as nano-thermometers inside cells. The chart on the left is a compilation of fluorescent lifetime micrographs showing the molecules' response to temperature, in Celsius. At right, the structure of the molecule shows the rotor, at bottom, which is modified to restrict 360-degree rotation.

Credit: Meredith Ogle/Rice University

That's now possible thanks to research by Rice University scientists who used the light-emitting properties of particular molecules to create a fluorescent nano-thermometer.

The Rice lab of chemist Angel Martí revealed the technique in a Journal of Physical Chemistry B paper, describing how it modified a biocompatible molecular rotor known as boron dipyrromethene (BODIPY, for short) to reveal temperatures inside single cells.

The molecule is ideally suited to the task. Its fluorescence lasts only a little while inside the cell, and the duration depends heavily on changes in both temperature and the viscosity of its environment. But at high viscosity, the environment in typical cells, its fluorescence lifetime depends on temperature alone.

It means that at a specific temperature, the light turns off at a particular rate, and that can be seen with a fluorescence-lifetime imaging microscope.

Martí said colleagues at Baylor College of Medicine challenged him to develop the technology. "Everybody knows old thermometers based on the expansion of mercury, and newer ones based on digital technology," he said.

"But using those would be like trying to measure the temperature of a person with a thermometer the size of the Empire State Building."

The technique depends on the rotor. Martí and Rice graduate student and lead author Meredith Ogle constrained the rotor to go back and forth, like the flywheel in a watch, rather than letting it rotate fully.

"It pretty much wobbles," Martí said.

"What we measure is how long the molecule stays in the excited state, which depends on how fast it wobbles," he said. "If you increase the temperature, it wobbles faster, and that shortens the time it stays excited."

The effect, Martí said, is conveniently independent of the concentration of BODIPY molecules in the cell and of photobleaching, the point at which the molecule's fluorescent capabilities are destroyed.

"If the environment is a bit more viscous, the molecule will rotate slower," Martí said. "That doesn't necessarily mean it's colder or hotter, just that the viscosity of the environment is different.

"We found out that if we constrain the rotation of this motor, then at high viscosities, the internal clock -- the lifetime of this molecule -- becomes completely independent of viscosity," he said. "This is not particularly common for these kind of probes."

Martí said the technique might be useful for quantifying the effects of tumor ablation therapy, where heat is used to destroy cancer cells, or in simply measuring for the presence of cancers. "They have a higher metabolism than other cells, which means they're likely to generate more heat," he said. "We'd like to know if we can identify cancer cells by the heat they produce and differentiate them from normal cells."

###

Co-authors of the paper are Rice graduate student Ashleigh Smith McWilliams; Matthew Ware, a scientist at Celgene Co., San Diego; Steven Curley, a surgeon at Christus Mother Frances Hospital, Tyler, Texas; and Stuart Corr, an assistant professor of surgical research and director of surgical innovation and technology development at Baylor College of Medicine.

The Dunn Collaborative Research Grant Program and the Optical Imaging and Vital Microscopy Core at Baylor College of Medicine, funded by the National Institutes of Health, supported the research.

Read the abstract at https://pubs.acs.org/doi/10.1021/acs.jpcb.9b04384.

This news release can be found online at http://news.rice.edu/2019/08/22/temperatures-inside-cells-taken-by-nano-thermometer-2/

Follow Rice News and Media Relations on Twitter @RiceUNews.

Related materials:

Angel Martí Group: https://martigroup.rice.edu

Rice Department of Chemistry: https://chemistry.rice.edu

Wiess School of Natural Sciences: https://naturalsciences.rice.edu

Image for download:

https://news-network.rice.edu/news/files/2019/08/0826_TEMP-1-WEB.jpg

Rice University chemists modified BODIPY molecules to serve as nano-thermometers inside cells. The chart on the left is a compilation of fluorescent lifetime micrographs showing the molecules' response to temperature, in Celsius. At right, the structure of the molecule shows the rotor, at bottom, which is modified to restrict 360-degree rotation. (Credit: Meredith Ogle/Rice University)

Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation's top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 3,962 undergraduates and 3,027 graduate students, Rice's undergraduate student-to-faculty ratio is just under 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice is ranked No. 1 for lots of race/class interaction and No. 4 for quality of life by the Princeton Review. Rice is also rated as a best value among private universities by Kiplinger's Personal Finance.

Mike Williams
713-348-6728
mikewilliams@rice.edu

Media Contact

Mike Williams
mikewilliams@rice.edu
713-348-6728

 @RiceUNews

http://news.rice.edu 

Mike Williams | EurekAlert!
Further information:
http://news.rice.edu/2019/08/22/temperatures-inside-cells-taken-by-nano-thermometer-2/
http://dx.doi.org/10.1021/acs.jpcb.9b04384

More articles from Life Sciences:

nachricht Blocking the iron transport could stop tuberculosis
02.04.2020 | University of Zurich

nachricht Discovery of life in solid rock deep beneath sea may inspire new search for life on Mars
02.04.2020 | University of Tokyo

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A sensational discovery: Traces of rainforests in West Antarctica

90 million-year-old forest soil provides unexpected evidence for exceptionally warm climate near the South Pole in the Cretaceous

An international team of researchers led by geoscientists from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) have now...

Im Focus: Blocking the Iron Transport Could Stop Tuberculosis

The bacteria that cause tuberculosis need iron to survive. Researchers at the University of Zurich have now solved the first detailed structure of the transport protein responsible for the iron supply. When the iron transport into the bacteria is inhibited, the pathogen can no longer grow. This opens novel ways to develop targeted tuberculosis drugs.

One of the most devastating pathogens that lives inside human cells is Mycobacterium tuberculosis, the bacillus that causes tuberculosis. According to the...

Im Focus: Physicist from Hannover Develops New Photon Source for Tap-proof Communication

An international team with the participation of Prof. Dr. Michael Kues from the Cluster of Excellence PhoenixD at Leibniz University Hannover has developed a new method for generating quantum-entangled photons in a spectral range of light that was previously inaccessible. The discovery can make the encryption of satellite-based communications much more secure in the future.

A 15-member research team from the UK, Germany and Japan has developed a new method for generating and detecting quantum-entangled photons at a wavelength of...

Im Focus: Junior scientists at the University of Rostock invent a funnel for light

Together with their colleagues from the University of Würzburg, physicists from the group of Professor Alexander Szameit at the University of Rostock have devised a “funnel” for photons. Their discovery was recently published in the renowned journal Science and holds great promise for novel ultra-sensitive detectors as well as innovative applications in telecommunications and information processing.

The quantum-optical properties of light and its interaction with matter has fascinated the Rostock professor Alexander Szameit since College.

Im Focus: Stem Cells and Nerves Interact in Tissue Regeneration and Cancer Progression

Researchers at the University of Zurich show that different stem cell populations are innervated in distinct ways. Innervation may therefore be crucial for proper tissue regeneration. They also demonstrate that cancer stem cells likewise establish contacts with nerves. Targeting tumour innervation could thus lead to new cancer therapies.

Stem cells can generate a variety of specific tissues and are increasingly used for clinical applications such as the replacement of bone or cartilage....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

13th AKL – International Laser Technology Congress: May 4–6, 2022 in Aachen – Laser Technology Live already this year!

02.04.2020 | Event News

“4th Hybrid Materials and Structures 2020” takes place over the internet

26.03.2020 | Event News

Most significant international Learning Analytics conference will take place – fully online

23.03.2020 | Event News

 
Latest News

Scientists see energy gap modulations in a cuprate superconductor

02.04.2020 | Physics and Astronomy

AI finds 2D materials in the blink of an eye

02.04.2020 | Information Technology

New 3D cultured cells mimic the progress of NASH

02.04.2020 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>