size determine interaction bwtn nanoparticles and membrane

Imperial researchers have tested whether gold nanoparticles could be toxic to cells, finding how they affect lipid membranes depends on their size.

Nanoparticles come in a wide variety of sizes, shapes and materials, and biological systems are complex, making determining how they interact with each other difficult to study. However, researchers know that one of the key first steps in toxicity is when a particle interacts with the membrane around a cell.

Particles can attach to the outsides of membranes, become embedded within in them, or be completely engulfed and enter the cell. Each of these outcomes can affect the cell in different ways; for example, distorting the membrane can affect its elastic properties, potentially affecting its ability to function.

Now, researchers from Imperial College London have tested gold nanoparticles with artificial cells, finding that how they interact depends on the size of the nanoparticles, with smaller nanoparticles (5-10 nm) most able to enter cell membranes.

Gold nanoparticles are being investigated for a number of uses inside the body, including aiding in tumour detection and for delivering drugs or gene therapy agents. The nanoparticles are usually 'functionalised' – coated with molecules that help them target specific receptors in cell membranes that allow them to interact with or enter the cell.

However, it was unknown whether functionalisation was always necessary for interaction, or whether the nanoparticles could interact spontaneously. The team tested different sizes of non-functionalised gold nanoparticles with artificial cells that mimic the properties of biological cell membranes. Using these simple cell mimics allowed them to focus on the membrane-nanoparticle interactions.

 

 

Reference

Size dependency of gold nanoparticles interacting with model membranes. Nature Communications Chemistry. doi.org/10.1038/s42004-020-00377-y