Featured Research

from universities, journals, and other organizations

Deliver drugs within the body with precision with the help of liposomes?

Date:
April 29, 2010
Source:
National Institute of Standards and Technology (NIST)
Summary:
Scientists have defined the workings of a new technique for making liquid-filled vesicles called liposomes, "fat bubbles" that may one day be used to precisely deliver drugs within the body. The new insight could help make a microchip-scale liposome manufacturing process practical.

Computer simulations showing the mixing of water and isopropyl alcohol in a COMMAND microfluidic device. The alcohol, which would contain dissolved phospolipids in operation, flows from the left to the right via the center inlet and is focused by water flowing in from the top and bottom inlets. Adjusting flow rates gives a tightly focused stream (top) or a broader one (bottom), controlling liposome size.
Credit: NIST

Pop a bubble while washing the dishes and you're likely to release a few drops of water trapped when the soapy sphere formed. A few years ago, researchers at the National Institute of Standards and Technology (NIST) pioneered a method using a microscopic fluidic (microfluidic) device that exploits the same principle to create liquid-filled vesicles called liposomes from phospholipids, the fat complexes that are the building blocks for animal cell membranes. These structures are valued for their potential use as agents to deliver drugs directly to cancers and other disease cells within the body.

Widespread application of liposomes as artificial drug carriers has been hindered by a number of limiting factors such as inconsistency in size, structural instability and high production costs. In a new study, the NIST and University of Maryland (UM) researchers have detailed the operation of their liposome manufacturing technique -- known as COMMAND for COntrolled Microfluidic Mixing And Nanoparticle Determination -- in order to maximize its effectiveness. Their goal was to better understand how COMMAND works as it produces liposomes with diameters controlled from about 50 to 150 nanometers (billionths of a meter) that are consistently uniform in size and inexpensively produced in what might be called an "assembly-line-on-a-microchip."

The researchers fabricate the COMMAND microfluidic devices by etching tiny channels into a silicon wafer with the same techniques used for making integrated circuits. In COMMAND, phospholipid molecules dissolved in isopropyl alcohol are fed via a central inlet channel into a "mixer" channel and "focused" into a fluid jet by a water-based solution (that in production would carry a drug or other cargo for the vesicles) added through two side channels. The components blend together as they mix by diffusion across the interfaces of the flowing fluid streams, directing the phospholipid molecules to self-assemble into nanoscale vesicles of controlled size. Different microfluidic device designs and fluid flow conditions were tested to investigate their role in producing liposomes.

The research team found that their liposome manufacturing process fundamentally depends on the flow and mixing of the fluid streams. The size of the liposomes can be "tuned" by manipulating the fluid flow rates, which in combination with the dimensions of the microfluidic device, determine the resulting mixing conditions. A tightly focused stream of phospholipid-carrying alcohol flowing at a slow rate tends to mix quickly with the buffer at the beginning of the mixing channel and forms small vesicles. A loosely focused stream flowing at a fast rate travels farther down the length of the mixing channel, allowing more mixing time and yielding larger vesicles.

The geometry of the channels plays an additional role, the researchers noted, in regulating the speed of production and the quantity and concentration of liposomes manufactured. This may be important for future clinical applications of liposomes as well as the integration of COMMAND into more complicated microchip systems for health care.


Story Source:

The above story is based on materials provided by National Institute of Standards and Technology (NIST). Note: Materials may be edited for content and length.


Journal References:

  1. Jahn et al. Controlled Vesicle Self-Assembly in Microfluidic Channels with Hydrodynamic Focusing. Journal of the American Chemical Society, 2004; 126 (9): 2674 DOI: 10.1021/ja0318030
  2. Jahn et al. Microfluidic Mixing and the Formation of Nanoscale Lipid Vesicles. ACS Nano, 2010; 4 (4): 2077 DOI: 10.1021/nn901676x

Cite This Page:

National Institute of Standards and Technology (NIST). "Deliver drugs within the body with precision with the help of liposomes?." ScienceDaily. ScienceDaily, 29 April 2010. <www.sciencedaily.com/releases/2010/04/100428142334.htm>.
National Institute of Standards and Technology (NIST). (2010, April 29). Deliver drugs within the body with precision with the help of liposomes?. ScienceDaily. Retrieved August 28, 2014 from www.sciencedaily.com/releases/2010/04/100428142334.htm
National Institute of Standards and Technology (NIST). "Deliver drugs within the body with precision with the help of liposomes?." ScienceDaily. www.sciencedaily.com/releases/2010/04/100428142334.htm (accessed August 28, 2014).

Share This




More Matter & Energy News

Thursday, August 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Australian Airlines Relax Phone Ban Too

Australian Airlines Relax Phone Ban Too

Reuters - Business Video Online (Aug. 26, 2014) Qantas and Virgin say passengers can use their smartphones and tablets throughout flights after a regulator relaxed a ban on electronic devices during take-off and landing. As Hayley Platt reports the move comes as the two domestic rivals are expected to post annual net losses later this week. Video provided by Reuters
Powered by NewsLook.com
Hurricane Marie Brings Big Waves to California Coast

Hurricane Marie Brings Big Waves to California Coast

Reuters - US Online Video (Aug. 26, 2014) Huge waves generated by Hurricane Marie hit the Southern California coast. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Chinese Researchers Might Be Creating Supersonic Submarine

Chinese Researchers Might Be Creating Supersonic Submarine

Newsy (Aug. 26, 2014) Chinese researchers have expanded on Cold War-era tech and are closer to building a submarine that could reach the speed of sound. Video provided by Newsy
Powered by NewsLook.com
Breakingviews: India Coal Strained by Supreme Court Ruling

Breakingviews: India Coal Strained by Supreme Court Ruling

Reuters - Business Video Online (Aug. 26, 2014) An acute coal shortage is likely to be aggravated as India's supreme court declared government coal allocations illegal, says Breakingviews' Peter Thal Larsen. Video provided by Reuters
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:
from the past week

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