Showing posts with label nanofiber. Show all posts
Showing posts with label nanofiber. Show all posts

Wednesday, March 14, 2012

Nanofiber breakthrough holds promise for medicine and microprocessors

 A new method for creating nanofibers made of proteins, developed by researchers at Polytechnic Institute of New York University (NYU-Poly), promises to greatly improve drug delivery methods for the treatment of cancers, heart disorders and Alzheimer's disease, as well as aid in the regeneration of human tissue, bone and cartilage.


In addition, applied differently, this same development could point the way to even tinier and more powerful microprocessors for future generations of computers and consumer electronics devices.


The details are spelled out in an article titled "Effects of Divalent Metals on Nanoscopic Fiber Formation and Small Molecule Recognition of Helical Proteins," which appears online in Advanced Functional Materials. Author Susheel K. Gunasekar, a doctoral student in NYU-Poly's Department of Chemical and Biological Sciences, was the primary researcher, and is a student of co-author Jin Montclare, assistant professor and head of the department's Protein Engineering and Molecular Design Lab, where the underlying research was primarily conducted. Also involved were co-authors Luona Anjia, a graduate student, and Professor Hiroshi Matsui, both of the Department of Chemistry and Biochemistry at Hunter College (The City University of New York), where secondary research was conducted.


Yet all of this almost never emerged, says Professor Montclare, who explains that it was sheer "serendipity" -- a chance observation made by Gunasekar two years ago -- that inspired the team's research and led to its significant findings.


During an experiment that involved studying certain cylinder-shaped proteins derived from cartilage oligomeric matrix protein (COMP, found predominantly in human cartilage), Gunasekar noticed that in high concentrations, these alpha helical coiled-coil proteins spontaneously came together and self-assembled into nanofibers. It was a surprising outcome, Montclare says, because COMP was not known to form fibers at all. "We were really excited," she recalls. "So we decided to do a series of experiments to see if we could control the fiber formation, and also control its binding to small molecules, which would be housed within the protein's cylinder."


Of special interest were molecules of curcumin, an ingredient in dietary supplements used to combat Alzheimer's disease, cancers and heart disorders.


By adding a set of metal-recognizing amino acids to the coiled-coil protein, the NYU-Poly team succeeded, finding that the nanofibers alter their shapes upon addition of metals such as zinc and nickel to the protein. Moreover, the addition of zinc fortified the nanofibers, enabling them to hold more curcumin, while the addition of nickel transformed the fibers into clumped mats, triggering the release of the drug molecule.


Next, Montclare says, the researchers plan to experiment with creating scaffolds of nanofibers that can be used to induce the regeneration of bone and cartilage (via embedded vitamin D) or human stem cells (via embedded vitamin A).


Later, it may even be possible to apply this organic, protein-based method for creating nanofibers to the world of computers and consumer electronics, Montclare says -- producing nanoscale gold threads for use as circuits in computer chips by first creating the nanofibers and then guiding that metal to them.


Ultimately, Montclare says, the researchers would like the fruits of their discovery -- such therapeutic nanofibers and metallic nanowires -- to be adopted by pharmaceutical companies and microprocessor makers alike.


Funding for this NYU-Poly research was provided by the U.S. Air Force Office of Scientific Research, the U.S. Army Research Office, the U.S. Department of Energy and the National Science Foundation.


Story Source:



The above story is reprinted from materials provided by Polytechnic Institute of New York University.


Note: Materials may be edited for content and length. For further information, please contact the source cited above.


Journal Reference:

Susheel K. Gunasekar, Luona Anjia, Hiroshi Matsui, Jin K. Montclare. Effects of Divalent Metals on Nanoscopic Fiber Formation and Small Molecule Recognition of Helical Proteins. Advanced Functional Materials, 2012; DOI: 10.1002/adfm.201101627

Saturday, April 16, 2011

Caught red-handed: Detection of latent fingerprints through release of fluorescein from a nanofiber mat

When a forensic agent dusts a surface with powder or exposes it to the vapors of an iodine chamber, mystery fans know what is going on: This is how latent fingerprints are made visible so that they can be compared to those of a suspect. Su Chen and a team at Nanjing University of Technology have now developed a new process for especially rapid and simple detection of fingerprints. As the Chinese researchers report in the journal Angewandte Chemie, all it takes is a special nanofiber mat that is pressed onto the suspect surface and briefly treated with hot air -- the fingerprints appear as red ridge patterns.


When we touch a surface, tiny traces of perspiration and oils stay behind, mirroring the ridge patterns on our fingertips. There are now a number of different methods to make these latent fingerprints visible. The new method is significantly faster than the classic technique of dusting with powder. Unlike spectroscopic methods, it does not require complex technical instruments, and problematic chemicals like ninydrin are not needed either. In addition, it is suitable for all types of surfaces: by lightly pressing the mat onto the surface, the researchers were able to reliably transfer fingerprints from a wide variety of materials, including steel, quartz, glass, plastic, marble, and wood.


The secret of their success is the special mat, a fleece made from nanofibers of thermoplastic polyurethane and fluorescein, a dye. The mat is made in a process called electrospinning. When the mat comes into contact with a fingerprint, components of the perspiration react with the polyurethane, causing cross-linking of the . The hot air accelerates the reaction. In the cross-linked regions, the fluorescein cannot remain within the fibers so it comes out as a powdery solid. However, the dye only fluoresces when it is very finely dispersed in the nanofibers, not when it is in small solid clumps. This causes the color of the mat to change from straw yellow to red, making the fingerprint visible within 30 seconds in daylight. The method only works with , because only they have enough surface area to produce a visible reaction.


The mat can identify more than mere fingerprints. The researchers were able to "print" an image of a small dragon onto the mat by using an ink-jet printer. Their ink was simply water, which can also cause the cross-linking reaction. The combination of ink-jet printing and the release of a chemical from a nanofiber mat could also be used to produce miniaturized systems such as sensors, microreactors, and diagnostic chips.


More information: Su Chen, et al., A Release-Induced Response for the Rapid Recognition of Latent Fingerprints and Formation of Inkjet-Printed Patterns, Angewandte Chemie International Edition 2011, 50, No. 16, 3706–3709, Permalink to the article: http://dx.doi.org/ … ie.201006537


Provided by Wiley (news : web)