Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

NIST, Maryland researchers COMMAND a better class of liposomes

29.04.2010
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.

* A. Jahn, W.N. Vreeland, M. Gaitan and L.E. Locascio. Controlled vesicle self-assembly in microfluidic channels with hydrodynamic focusing. Journal of the American Chemical Society. Vol. 126, 2674-2675 (Feb. 17, 2004).

** A. Jahn, S.M. Stavis, J.S. Hong, W.N. Vreeland, D.L. DeVoe and M. Gaitan. Microfluidic mixing and the formation of nanoscale lipid vesicles. ACS Nano. Published online March 31, 2010.

Michael E. Newman | EurekAlert!
Further information:
http://www.nist.gov

More articles from Life Sciences:

nachricht Flow of cerebrospinal fluid regulates neural stem cell division
21.05.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Chemists at FAU successfully demonstrate imine hydrogenation with inexpensive main group metal
21.05.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

Im Focus: Computer-Designed Customized Regenerative Heart Valves

Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.

Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...

Im Focus: Light-induced superconductivity under high pressure

A team of scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg investigated optically-induced superconductivity in the alkali-doped fulleride K3C60under high external pressures. This study allowed, on one hand, to uniquely assess the nature of the transient state as a superconducting phase. In addition, it unveiled the possibility to induce superconductivity in K3C60 at temperatures far above the -170 degrees Celsius hypothesized previously, and rather all the way to room temperature. The paper by Cantaluppi et al has been published in Nature Physics.

Unlike ordinary metals, superconductors have the unique capability of transporting electrical currents without any loss. Nowadays, their technological...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Supersonic waves may help electronics beat the heat

18.05.2018 | Power and Electrical Engineering

Keeping a Close Eye on Ice Loss

18.05.2018 | Information Technology

CrowdWater: An App for Flood Research

18.05.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>