Magnetic nanoparticles make attractive partners in purification processes

(Nanowerk News) Biotechnology has led to new cutting-edge drugs, foods with health benefits, and specialised animal feed. But extracting functional ingredients from mixes to produce such products can be costly – a high level of purity is needed.

For example, current separation processes to purify high-value proteins with health functions can eat up to around 80 % of production costs, says Matthias Franzreb, an executive board member of the EU-funded MagPro2Life project and an engineering professor at Germany’s Karlsruhe Institute of Technology. These processes include filtration, centrifugation and purification steps.

MagPro2Life has gone some way to cutting such costs by developing three pilot manufacturing plants to demonstrate the feasibility of a novel purification process for proteins that uses magnetic adsorbent micro and nanoparticles.

The techniques developed during the project were based on research findings from NanoBioMag, another EU-funded project.

Since the end of the MagPro2Life in June 2013, the partners have been working on the next stage – moving from pilot to factory production.
How they did it
MagPro2Life’s researchers first developed a cheaper way to produce large quantities of magnetic nanoparticles. The nanoparticles have specific properties that allow them to adsorb particular biological molecules – only those that are the targets of a purification process.
The researchers also developed new smart functionalities for magnetic nanoparticles, extending the range of target molecules they can bind and consequently extract from a mix. This mix could be fermentation broths, plasma, milk, whey and plant extracts, for example.
MagPro2Life’s magnetic centrifuge, which combines the advantages of magnetic separation and centrifugation, was the first of its type developed for biotech applications, says Franzreb.
The process works as follows: the magnetic nanoparticles are put into a mixture where they quickly bind the target molecules. The magnetic centrifuge extracts the nanoparticles, along with their piggybacking molecules.
After an intermediate washing step to get rid of any impurities, chemicals are used to separate the purified molecules from the nanoparticles – ready to be used for manufacturing a novel drug, food or feed product.
The magnetic nanoparticles can then be reused, once they have been washed clean of any remaining molecules.
“Magnetic nanoparticles are pretty hard to create,” says Franzreb. “Reusing them is a key way to bring costs down.”
Pilot plants put theory into practice
The researchers demonstrated the magnetic extraction technique through three pilot plants, one each for food, pharma and feed production.
Solae, the project’s coordinator, developed one pilot to extract valuable proteins left over from processing soy at the company’s food production plant in Aarhus, Denmark. The proteins are being investigated for anticarcinogenic properties.
The technology, although still in the early stages, could be a game-changer for how proteins are separated, resulting in better functionality and nutrition, says Torkel Rhenman, Solae’s chief executive at the time of the project. It could also lead to new speciality ingredients that cannot be economically produced with current technology.
“Achievement of these milestones is significant because this novel technology has never been applied in the food industry,” he adds. "It could be very flexible in separating many different protein sources, producing proteins with unique properties and health benefits."
The pharmaceutical pilot line was built at a laboratory of the UK’s University of Birmingham, and resulted in the successful extraction of an antibody fragment from a mixture.
The feed production pilot, at the Karlsruhe Institute of Technology, targeted the direct extraction of an enzyme from a mix during fermentation, but was not so straightforward – some other cells were separated along with the target enzyme. Franzreb is confident a solution can be found by improving the selectivity of the adsorbents and of the separator.
“MagPro2Life showed that the process is viable commercially,” he adds. “Establishing new technologies for pharma and food processing is the long-term goal. These are multi-billion euro markets and even if a small share could be gained for magnet technology, it would have a substantial impact on competitiveness.”
Source: European Commission