Scientists overcome nanotech hurdle

When you make a new material on a nanoscale how can you see what you have made? A team lead by a Biotechnology and Biological Sciences research Council (BBSRC) fellow has made a significant step toward overcoming this major challenge faced by nanotechnology scientists.

With new research published today (13 August) in ChemBioChem, the team from the University of Liverpool, The School of Pharmacy (University of London) and the University of Leeds, show that they have developed a technique to examine tiny protein molecules called peptides on the surface of a gold nanoparticle. This is the first time scientists have been able to build a detailed picture of self-assembled peptides on a nanoparticle and it offers the promise of new ways to design and manufacture novel materials on the tiniest scale - one of the key aims of nanoscience.

Engineering new materials through assembly of complex, but tiny, components is difficult for scientists. However, nature has become adept at engineering nanoscale building blocks, e.g. proteins and RNA. These are able to form dynamic and efficient nanomachines such as the cell's protein assembly machine (the ribosome) and minute motors used for swimming by bacteria. The BBSRC-funded team, led by Dr Raphaël Lévy, has borrowed from nature, developing a way of constructing complex nanoscale building blocks through initiating self-assembly of peptides on the surface of a metal nanoparticle. Whilst this approach can provide a massive number and diversity of new materials relatively easily, the challenge is to be able to examine the structure of the material.

Using a chemistry-based approach and computer modelling, Dr Lévy has been able to measure the distance between the peptides where they sit assembled on the gold nanoparticle. The technique exploits the ability to distinguish between two types of connection or 'cross-link' - one that joins different parts of the same molecule (intramolecular), and another that joins together two separate molecules (intermolecular). As two peptides get closer together there is a transition between the two different types of connection.

Computer simulations allow the scientists to measure the distance at which this transition occurs, and therefore to apply it as a sort of molecular ruler. Information obtained through this combination of chemistry and computer molecular dynamics shows that the interactions between peptides leads to a nanoparticle that is relatively organized, but not uniform. This is the first time it has been possible to measure distances between peptides on a nanoparticle and the first time computer simulations have been used to model a single layer of self-assembled peptides.

Dr Lévy said: "As nanotechnology scientists we face a challenge similar to the one faced by structural biologists half a century ago: determining the structure with atomic scale precision of a whole range of nanoscale materials. By using a combination of chemistry and computer simulation we have been able to demonstrate a method by which we can start to see what is going on at the nanoscale.

"If we can understand how peptides self-assemble at the surface of a nanoparticle, we can open up a route towards the design and synthesis of nanoparticles that have complex surfaces. These particles could find applications in the biomedical sciences, for example to deliver drugs to a particular target in the body, or to design sensitive diagnostic tests. In the longer term, these particles could also find applications in new generations of electronic components."

Professor Nigel Brown, BBSRC Director of Science and Technology, said: "Bionanotechnology holds great promise for the future. We may be able to create stronger, lighter and more durable materials, or new medical applications. Basic science and techniques for working at the nanoscale are providing the understanding that will permit future such applications of bionanotechnology."

Source: BBSRC

Related stories:

Unregulated nanoparticles from diesel engines inhibit lungs
(PhysOrg.com) -- Diesel engines emit countless carbon nanoparticles into the air, slipping through government regulation and vehicle filters. A new University of Michigan simulation shows that these nanoparticles can get trapped in the lungs and inhibit the function of a fluid that facilitates breathing.
An alternative to chemotherapy: Nanoparticles tackle pediatric brain tumors
An interdisciplinary team of researchers at Washington University in St. Louis, led by Karen L. Wooley, Ph.D., James S. McDonnell Distinguished University Professor in Arts & Sciences, is a step closer to delivering cancer-killing drugs to pediatric brain tumors, similar to the tumor that Senator Ted Kennedy is suffering from.
Stripes key to nanoparticle drug delivery
In work that could at the same time impact the delivery of drugs and explain a biological mystery, MIT engineers have created the first synthetic nanoparticles that can penetrate a cell without poking a hole in its protective membrane and killing it. The key to their approach? Stripes.
Gold nanoparticle probes may allow earlier cancer detection
Using tiny gold particles embedded with dyes, researchers have shown that they can identify tumors under the skin of a living animal. These tools may allow doctors to detect and diagnose cancer earlier and less invasively.
Developing a modular, nanoparticle drug delivery system
There are two aspects to creating an effective drug: finding a chemical compound that has the desired biological effect and minimal side-effects and then delivering it to the right place in the body for it to do its job.
Pairing nanoparticles with proteins
In groundbreaking research, scientists have demonstrated the ability to strategically attach gold nanoparticles -- particles on the order of billionths of a meter -- to proteins so as to form sheets of protein-gold arrays.
In nature, proteins sweep up nanoparticles
Here’s a pollution-control tip from nature: Deep inside a flooded mine in Wisconsin, scientists from several institutions including the U.S. Department of Energy’s Lawrence Berkeley National Laboratory have discovered a world in which bacteria emit proteins that sweep up metal nanoparticles into immobile clumps. Their finding may lead to innovative ways to remediate subsurface metal toxins.
Scientists collaborate to study biologically assembled quantum electronic systems
The U.S. Department of Defense is awarding a team of nine professors from six universities $6 million over five years to exploit precise biological assembly for the study of quantum physics in nanoparticle arrays. This research will help to produce a fundamental understanding of quantum electronic systems, which could impact the way future electronics are created.

News discussion:

Nanotechnology news