Speeding up quality control for biologics

May 22, 2017, Massachusetts Institute of Technology

Drugs manufactured by living cells, also called biologics, are one of the fastest-growing segments of the pharmaceutical industry. These drugs, often antibodies or other proteins, are being used to treat cancer, arthritis, and many other diseases.

Monitoring the quality of these drugs has proven challenging, however, because production by living cells is much more difficult to control than the synthesis of traditional drugs. Typically these drugs consist of small organic molecules produced by a series of chemical reactions.

MIT engineers have devised a new way to analyze biologics as they are being produced, which could lead to faster and more efficient safety tests for such drugs. The system, based on a series of nanoscale filters, could also be deployed to test drugs immediately before administering them, to ensure they haven't degraded before reaching the patient.

"Right now there is no mechanism for checking the validity of the protein postrelease," says Jongyoon Han, an MIT professor of electrical engineering and computer science. "If you have analytics that consume a very small amount of a sample but also provide critical safety information about aggregation and binding, we can think about point-of-care analytics."

Han is the senior author of the paper, which appears in the May 22 issue of Nature Nanotechnology. The paper's lead author is MIT postdoc Sung Hee Ko.

A complicated process

Many biologics are produced in "bioreactors" populated by cells that have been engineered to produce large quantities of certain proteins such as antibodies or cytokines (a type of signaling molecule used by the immune system). Some of these also require the addition of sugar molecules through a process known as glycosylation.

"Proteins are inherently more complicated than small-molecule drugs. Even if you run the same exact bioreactor process, you may end up with different proteins, with different glycosylation and different activity," Han says.

Although manufacturers can monitor bioreactor conditions such as temperature and pH, which may warn of potential problems, there is no way to test the quality of the proteins until after production is complete, and that process can take months.

"At the end of that process, you may or may not get a good batch. And if you happen to get a bad batch, this means a lot of waste in overall manufacturing workflow," Han says.

Han believed that nanofilters he had previously developed could be adapted to sort proteins by size as they flow through a tiny channel, which could allow for continuous, automatic monitoring as the proteins are produced. This size information can reveal whether the proteins have clumped together, which is a sign that the protein has lost its original structure.

After proteins enter the nanofilter array device, they are directed to one side of the wall. This narrow line of proteins then encounters a series of slanted filters with tiny pores (15 to 30 nanometers). The pores are designed so that smaller proteins will fit through them easily, while larger proteins will move along the diagonal for some distance before making it through one of the pores. This allows the proteins to be separated based on their size: Smaller proteins stay closer to the side where they started, while larger proteins drift toward the opposite side.

By changing the size of the pores, the researchers can use this system to separate proteins ranging in mass from 20 to hundreds of kilodaltons. This allows them to determine whether the proteins have formed large clumps that could provoke a dangerous immune response in patients.

The researchers tested their device on three proteins: human growth hormone; interferon alpha-2b, a cytokine that is being tested as a cancer ; and granulocyte-colony stimulating factor (GCSF), which is used to stimulate production of white blood cells.

To demonstrate the device's ability to reveal protein degradation, the researchers exposed these proteins to harmful conditions such as heat, hydrogen peroxide, and ultraviolet light. Separating the proteins through the nanofilter array device allowed the researchers to accurately determine if they had degraded or not.

Sorting by size can also reveal whether proteins bind to their intended targets. To do this, the researchers mixed the biologics with protein fragments that the drugs are meant to target. If the biologics and bind correctly, they form a larger protein with a distinctive size.

Rapid analysis

This nanofluidic system can analyze a small protein sample in 30 to 40 minutes, plus the few hours it takes to prepare the sample. However, the researchers believe they can speed that up by further miniaturizing the device.

"We may be able to do it in tens of minutes, or even a few minutes," Han says. "If we realize that, we may be able to do real point-of-care checks. That's the future direction."

Explore further: Manufacturing technique can make proteins less effective

More information: Nanofluidic device for continuous, multiparameter biologics quality assurance, Nature Nanotechnology (2017). nature.com/articles/doi:10.1038/nnano.2017.74

Related Stories

A new way to discover structures of membrane proteins

February 7, 2017

University of Toronto scientists have discovered a better way to extract proteins from the membranes that encase them, making it easier to study how cells communicate with each other to create human health and disease.

A more powerful way to develop therapeutics?

July 21, 2016

A University of Toronto scientist has developed a new method for identifying the raw ingredients necessary to build 'biologics', a powerful class of medications that has revolutionized treatment of diseases like rheumatoid ...

Recommended for you

Fish-inspired material changes color using nanocolumns

March 20, 2019

Inspired by the flashing colors of the neon tetra fish, researchers have developed a technique for changing the color of a material by manipulating the orientation of nanostructured columns in the material.

Researchers shed new light on the origins of modern humans

March 20, 2019

Researchers from the University of Huddersfield, with colleagues from the University of Cambridge and the University of Minho in Braga, have been using a genetic approach to tackle one of the most intractable questions of ...

One transistor for all purposes

March 20, 2019

In mobiles, fridges, planes – transistors are everywhere. But they often operate only within a restricted current range. LMU physicists have now developed an organic transistor that functions perfectly under both low and ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.