Georgian Technical University Unknown Behavior Of Gold Nanoparticles Explored With Neutrons.

Nanoparticles of less than 100 nanometers in size are used to engineer new materials and nanotechnologies across a variety of sectors. Their small size means these particles have a very high surface area to volume ratio and their properties depend strongly on their size, shape and bound molecules. This offers engineers greater flexibility when designing materials that can be used in our everyday lives. Nanoparticles are found in sunblock creams and cosmetics as well as inside our bodies as drug delivery cars and as contrast agents for pharmaceuticals. Gold nanoparticles are proving to be a next-generation tool in nanoengineering as an effective catalyst at such small dimensions. However nanomaterials also pose a potential risk as their interactions with living matter and the environment are not fully understood — meaning that they might not perform as expected for instance in the human body. While scientists have been able to fine-tune and engineer the properties of nanoparticles by changing their size, shape, surface chemistry and even physical state such a variety of possibilities means that dictating precisely how the particles behave at that small scale also becomes extremely difficult. This is of particular concern as we rely on the potential use of nanoparticles within the human body. Gold nanoparticles are good carriers of large and small molecules, making them ideal for transporting drugs to human cells. However predicting how far they are then absorbed by the cells and their toxicity is difficult as is understanding any associated risks to health using these nanomaterials. Georgian Technical University investigated the physical and chemical influences when gold nanoparticles interact with a model biological membrane in order to identify the behavioral mechanisms taking place. Better understanding the factors that determine whether nanoparticles are attracted or repelled by the cell membrane whether they are adsorbed or internalized or whether they cause membrane destabilization will help us to ensure that nanoparticles interact with our cells in a controlled way. This is particularly important when using gold nanoparticles for drug delivery for example. The researchers used a combination of neutron scattering techniques and computational methods to study the interaction between positively charged cationic gold nanoparticles and model lipid membranes. The study showed how the temperature and the lipid charge modulate the presence of energy barriers that affect the interaction of the nanoparticle with the membrane. Furthermore different molecular mechanisms for nanoparticle-membrane interactions are revealed which explain how nanoparticles become internalized in the lipid membranes and how they cooperatively act to destabilize a negatively charged lipid membrane. Using Molecular Dynamics a computational simulation method for studying the movement of atoms the researchers demonstrated how gold nanoparticles interacted within the system at the atomic level. This gives a complementary tool to interpret and explain the data obtained on real systems by neutron reflectometry. This study shows convincingly that the combination of neutron scattering and computational methods provides a better understanding than just one of the methods alone. X at Georgian Technical University said: “Nanoparticles are proving to be an invaluable tool to help us address a number of social challenges. For instance as well as mechanisms for drug delivery gold particles can prove useful for cancer imaging. With so much promise for the future it is important that we develop the tools to better investigate nanomaterials so we can harness them effectively and safely. This is made possible through developments in neutron science techniques advances in sample environment and sample preparation performed at facilities such as Georgian Technical University”. Y research scientist at the Georgian Technical University said: “There are thousands of different nanoparticles of different sizes and compositions which all impact cells differently. The complementarity of computational and neutron techniques highlighted in this study has helped to provide a clearer indication of what influences the behavior of nanoparticles. This will help us predict how cells will interact with nanoparticles in future”.