Featured Research

from universities, journals, and other organizations

'Nanosubmarine' designed that delivers complementary molecules inside cells

Date:
June 25, 2014
Source:
University of Miami
Summary:
Nanoparticles that under the right conditions, self-assemble -- trapping complementary guest molecules within their structure -- have been recently created by scientists. Like tiny submarines, these versatile nanocarriers can navigate in the watery environment surrounding cells and transport their guest molecules through the membrane of living cells to sequentially deliver their cargo.

The sequential transport of donors and acceptors across cell membranes with independent and dynamic nanocarriers enables energy transfer exclusively in the intracellular space with concomitant fluorescence activation.
Credit: Francisco Raymo, professor of Chemistry and director of the laboratory for molecular photonics, at the University of Miami College of Arts and Sciences

With the continuing need for very small devices in therapeutic applications, there is a growing demand for the development of nanoparticles that can transport and deliver drugs to target cells in the human body.

Recently, researchers created nanoparticles that under the right conditions, self-assemble -- trapping complementary guest molecules within their structure. Like tiny submarines, these versatile nanocarriers can navigate in the watery environment surrounding cells and transport their guest molecules through the membrane of living cells to sequentially deliver their cargo.

Although the transport of molecules inside cells with nanoparticles has been previously achieved using various methods, researchers have developed nanoparticles capable of delivering and exchanging complementary molecules. For practical applications, these nanocarriers are highly desirable, explains Francisco Raymo, professor of chemistry in the University of Miami College of Arts and Sciences and lead investigator of this project.

"The ability to deliver distinct species inside cells independently and force them to interact, exclusively in the intracellular environment, can evolve into a valuable strategy to activate drugs inside cells," Raymo says.

The new nanocarriers are15 nanometers in diameter. They are supramolecular constructs made up of building blocks called amphiphilic polymers. These nanocarriers hold the guest molecules within the confines of their water-insoluble interior and use their water-soluble exterior to travel through an aqueous environment. As a result, these nanovehicles are ideal for transferring molecules that would otherwise be insoluble in water, across a liquid environment.

"Once inside a living cell, the particles mix and exchange their cargo. This interaction enables the energy transfer between the internalized molecules," says Raymo, director of the UM laboratory for molecular photonics. "If the complementary energy donors and acceptors are loaded separately and sequentially, the transfer of energy between them occurs exclusively within the intracellular space," he says. "As the energy transfer takes place, the acceptors emit a fluorescent signal that can be observed with a microscope."

Essential to this mechanism are the noncovalent bonds that loosely hold the supramolecular constructs together. These weak bonds exist between molecules with complementary shapes and electronic properties. They are responsible for the ability of the supramolecules to assemble spontaneously in liquid environments. Under the right conditions, the reversibility of these weak noncovalent contacts allows the supramolecular constructs to exchange their components as well as their cargo.

The experiments were conducted with cell cultures. It is not yet known if the nanoparticles can actually travel through the bloodstream.

"That would be the dream, but we have no evidence that they can actually do so," Raymo says. "However, this is the direction we are heading."

The next phase of this investigation involves demonstrating that this method can be used to do chemical reactions inside cells, instead of energy transfers.

"The size of these nanoparticles, their dynamic character and the fact that the reactions take place under normal biological conditions (at ambient temperature and neutral environment) makes these nanoparticles an ideal vehicle for the controlled activation of therapeutics, directly inside the cells," Raymo says.

The current study is titled "Intracellular guest exchange between dynamic supramolecular hosts." It's published in the Journal of the American Chemical Society. Other authors are John F. Callan, co-corresponding author of the study, from the School of Pharmacy and Pharmaceutical Sciences at the University of Ulster; Subramani Swaminathan and Janet Cusido from the UM's Laboratory for Molecular Photonics, Department of Chemistry in the College of Arts and Sciences; and Colin Fowley and Bridgeen McCuaghan, School of Pharmacy and Pharmaceutical Sciences at the University of Ulster.


Story Source:

The above story is based on materials provided by University of Miami. Note: Materials may be edited for content and length.


Journal Reference:

  1. Subramani Swaminathan, Colin Fowley, Bridgeen McCaughan, Janet Cusido, John F. Callan, Franηisco M. Raymo. Intracellular Guest Exchange between Dynamic Supramolecular Hosts. Journal of the American Chemical Society, 2014; 136 (22): 7907 DOI: 10.1021/ja500285p

Cite This Page:

University of Miami. "'Nanosubmarine' designed that delivers complementary molecules inside cells." ScienceDaily. ScienceDaily, 25 June 2014. <www.sciencedaily.com/releases/2014/06/140625201934.htm>.
University of Miami. (2014, June 25). 'Nanosubmarine' designed that delivers complementary molecules inside cells. ScienceDaily. Retrieved October 20, 2014 from www.sciencedaily.com/releases/2014/06/140625201934.htm
University of Miami. "'Nanosubmarine' designed that delivers complementary molecules inside cells." ScienceDaily. www.sciencedaily.com/releases/2014/06/140625201934.htm (accessed October 20, 2014).

Share This



More Matter & Energy News

Monday, October 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Gulfstream G500, G600 Unveiling

Gulfstream G500, G600 Unveiling

Flying (Oct. 20, 2014) — Watch Gulfstream's public launch of the G500 and G600 at their headquarters in Savannah, Ga., along with a surprise unveiling of the G500, which taxied up under its own power. Video provided by Flying
Powered by NewsLook.com
Japanese Scientists Unveil Floating 3D Projection

Japanese Scientists Unveil Floating 3D Projection

Reuters - Innovations Video Online (Oct. 20, 2014) — Scientists in Tokyo have demonstrated what they say is the world's first 3D projection that floats in mid air. A laser that fires a pulse up to a thousand times a second superheats molecules in the air, creating a spark which can be guided to certain points in the air to shape what the human eye perceives as an image. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

3BL Media (Oct. 20, 2014) — Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-fuel Impala Video provided by 3BL
Powered by NewsLook.com
What We Know About Microsoft's Rumored Smartwatch

What We Know About Microsoft's Rumored Smartwatch

Newsy (Oct. 20, 2014) — Microsoft will reportedly release a smartwatch that works across different mobile platforms, has a two-day battery life and tracks heart rate. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins