Very small molecules can be used to produce functional materials with novel properties, yet it remains difficult to predict how these molecules interact with each other. We spoke to Dr Pim Frederix about his work in developing a computational framework that could help introduce a new level of predictability to biomaterial development.
A new path to biomaterial development
Three snapshots from a simulation of peptides self-assembling from randomly dissolved molecules into hollow vesicles, after which the vesicles fuse into a hollow tube. The peptide backbone forms the outer surface (shown in red) and peptide side chains the interior of the tube walls (in white).
The ability to make biomaterials out of very small molecules is still relatively new, building on the discovery in the ‘90s that these molecules, specifically peptides, can be used to produce the same functional materials as larger proteins. This spurred further research into using different
Biomaterial development This means introducing more predictability and structure into biomaterial development, work which could be of great interest to the commercial sector. While chemists nowadays can synthesise molecules with a large degree
People would think about what materials would work for a certain application, but they would never really know whether they had made a good choice until they tried to synthesise such a material. The idea of the project was to simplify this process and make it cheaper. types of molecules, derivatives, and shorter and shorter peptides to develop biomaterials for certain functions. “This is about really going down to the basic buildings blocks of the biological world, to see what you can still achieve in terms of materials,” says Dr Pim Frederix. Many promising molecules have since been found, yet research still often operates on a trial-and-error basis, an issue that Dr Frederix is addressing in a project funded by the Netherlands Organisation for Scientific Research (NWO). “People would think about what new materials would work for a certain application, but they would never really know whether they had made a good choice until they actually tried to synthesise such a material in the lab,” he explains. “The idea of the project was to simplify this discovery process and make it cheaper by using computer simulations before testing it in the lab.”
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of control over their properties, it remains very difficult to predict how they will interact with other molecules. “This is where simulations have really proved useful, in looking at how molecules could come together to form a material,” says Dr Frederix. Researchers are simulating molecular dynamics, aiming to understand their central characteristics. “We’re using a coarse-grain method, where we group certain amounts of atoms into single particles, and then study those particles. This can be done at various levels. We put four heavy atoms into a particle, based on functional groups in chemistry. A peptide amide group would be a certain type of particle for example. In this way we can distinguish between amino acids,” outlines Dr Frederix. “At the same time we are also speeding up simulations by a factor of roughly 1,000, so we can see more
things happening and identify whether those interactions are important for a system.” The ultimate goal in this research is to assess how small biomolecules interact with raw materials, including not just peptides but also lipids, proteins and other molecules. From there, researchers can then look to identify those materials which may be wellsuited to specific applications, for example in the food or pharmaceutical industries, and the research team has already identified several promising peptides. “We are in touch with a small company that uses our results to make biomaterials for cell culture,” says Dr Frederix. There are also other potential applications, including in sun protection. “A few peptides have been discovered to polymerise into compounds resembling melanin, which provides protection against UV radiation. A research group is currently looking into putting that product onto the market,” continues Dr Frederix. “We also ran a project with a company that makes icing for cakes, so there’s a food component as well. We hope to continue finding new applications.”
New Peptides for Food New peptides for food, pharmaceuticals and functional materials Dr Pim W.J.M. Frederix Post-doctoral research associate Groningen Biomolecular Sciences and Biotechnology Institute Stratingh Institute for Chemistry Rijksuniversiteit Groningen T: +31 (0)50 363 4329 E: p.w.j.m.frederix@rug.nl Dr Pim W. J. M. Frederix received his MSc Chemistry from Radboud University Nijmegen, The Netherlands. He moved to University of Strathclyde (Glasgow, UK) where he completed his PhD in Physics on the topic of ultrafast spectroscopy and bionanotechnology. After postdocs at University of Strathclyde and University of Groningen, he received a VENI grant from the Dutch Organisation for Scientific Research to pursue his interest in how small molecules self-assemble into nanostructures in the group of Siewert-Jan Marrink, using a combination of spectroscopy, microscopy and computational modelling.
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