Turning silkworms into biomedical solutions

How did you come to work at the Weizmann Institute of Science?

I obtained my PhD in chemistry from Bar-Ilan University, focusing on the effect of mechanical fields — covering the entire sound energy range, including ultrasounds — on protein structure. I then moved to the University of Cambridge and studied the protein self- assembly phenomenon, which is associated with neurodegenerative disorders. I also cooperated with a group from Oxford University working on spider silk. We discovered that, in terms of supramolecular organization, certain types of silks are to some extent similar to those protein structures associated with Alzheimer’s and Parkinson’s.

Years later, when I got an offer to set up my lab at the Weizmann Institute of Science, I decided to focus most of my research on the material aspects of protein constructs. We’re harnessing all the knowledge and techniques I learned and developed during my studies to understand how we can control and possibly change the protein self-assembly path — and, in turn, how these changes may affect the functionality of protein constructs and biomaterial properties.

Could you give us examples of the work you do at the Shimanovich Research Group?

As I mentioned, we’re looking at the protein self-assembly phenomenon. For example, using silkworms, we’re imposing genetic modifications on silk proteins and letting them self- assemble. Our aim is to understand how these mutations change the self assembly pathway and whether they affect various biological functions, functionalities or properties — like mechanical characteristics, the rate of biodegradability and biocompatibility.

We’re not limited to materials that are made purely from proteins — we’re also looking at different types of natural building blocks. We’ve recently explored the capabilities of polysaccharides from food-industry waste; they have an excellent thermal responsivity that can be converted into electrical currents, but the problem with utilizing them is their mechanical instability. We discovered that if we combine a conductive polysaccharide with silk — known for its mechanical stability — we can construct a multifunctional material that’s mechanically strong, biodegradable and thermo-responsive.

What are some real-life implications of these experiments?

The ability to control protein self-assembly, especially the one that’s associated with material performance, opens up endless possibilities for the synthesis of materials with programmable multifunctional characteristics. For example, the technology developed in our lab allows us to create both highly stiff material and very extensible biomaterial, all assembled from the same building blocks: silk proteins.

The range of biomedical applications vary from controlling cellular growth and differentiation to tissue replacement, where programmable mechanical performance, biocompatibility and slow biodegradability are essential.

How does all this relate to the topic of sustainability?

We’re using materials that are either considered waste products or available in large quantities. Silk protein, for example, is cheap and known for its broad utilization in the textile industry. Our aim is to create technology that’s as green and as cost-effective as possible.

Do students get to contribute to this work?

I work with many different people — postdocs, a research associate, a consultant, PhD students, master’s students, rotational students, visitors from different countries. I collaborate with other professors that come either for a sabbatical from other universities or as part of the visiting professorship program. We also work closely with high school students. The lab is also part of a program that lets high school students spend about a month or two in the summer on a specific project of their choosing.

You’re also a teacher. How do you try to impart a love of physical and chemical materials to your students?

I teach a course in soft biomaterials and self-assembly at the Institute’s Feinberg Graduate School. The aim of the class is to provide students with knowledge about basic physical or chemical concepts related to the processing of natural building blocks, such as sugars, lipids and proteins. I try to identify and work with each student during the course; at Weizmann, class sizes are usually small, which means I get to work one-on-one and understand individual needs.

For their end-of-course presentation, I ask students to create a food dish or a cosmetic, either at home or in a lab, and then explain the physical and chemical processes involved in the task, such as heat transfer or emulsification and preservation of active ingredients. The idea is that when students perform something — even a small experiment — by themselves, they’re able to translate the knowledge they’ve acquired in class into practice, thinking about which processes are actually involved in a lab experiment.

Turning silkworms into biomedical solutions

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