Xiaozhu “Zack” Zhou:
From Auto Bodies to Human Bodies: Using Materials Science in Biotech

You may not realize it right away, but filters are all around us. Filters abound, in the masks we have been wearing during the pandemic, in our homes’ taps for clean water, in our buildings for clean air—the list goes on and on. In the biotech world, filters are critical in every step of the manufacturing of biological molecules, from the harvesting of cells that grow the medicines to ensuring that the medicines are free from pathogens and other contaminants. 

It’s no wonder that large biopharmaceutical companies like Amgen have on their staff filtration experts like Xiaozhu “Zack” Zhou. As the filtration subject matter expert for Amgen, Zhou has had a busy couple of years. Supply-chain shortages for the raw materials for the filters Amgen uses in making and purifying its products have meant a lot of creative problem solving.

Zhou began at Amgen Massachusetts in 2019, right before the pandemic began, to advise on issues related to filtration in manufacturing across all the company’s sites globally. In 2020, the job shifted substantially, as the distribution of the raw materials that go into the filters was prioritized for critical vaccine and monoclonal antibody treatment development to address COVID-19. 

“Think about the scale of the vaccine manufacturing alone,” Zhou explains. “We are talking about several billion doses. It's a challenging endeavor, and requires a lot of coordination, especially for the raw materials required to develop and sterilize the vaccines.”

As the delivery of filters to Amgen was delayed with little or no notice, Zhou and others had to begin brainstorming for solutions. It has not been easy, due to the important and complex regulations that surround biological manufacturing. “We have developed a strategy to mitigate the risks at each step of the process to identify the best alternative suppliers and keep producing critical medicines,” he says.

Zhou says that a lot of the work is in comparing the performance and safety of different filters for different steps in manufacturing. “It's not easy to plug and play and just change to a different filter because every filter has its own quirks that could change a process,” he says. “Think about the options on the market for water filters. You can see varying performance between different suppliers; for example, some filters can last for a week, and some can last a month.”

Before his work at Amgen, Zhou worked at MilliporeSigma, developing next-generation filters. “I've seen both sides, having developed the products and now advising on which to use and how to use them,” he explains. And before working with filters, he worked on paint-coating products for automobile manufacturing—joking that he went from working on materials science challenges for auto bodies to challenges for human bodies.

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Zach Zhou and his sons

A trained materials scientist, Zhou grew up in China and remembers being fascinated with physics and chemistry beginning in middle school and then through to high school when he did some lab experiments. In college at Zhejiang University in China, he decided to enroll in the materials science program, as it incorporated both physics and chemistry. That led him to obtain his PhD at Nanyang Technological University in Singapore. Zhou then went on to do postdoctoral work at Northwestern University in the United States, focusing on chemistry and biotechnology. 

The biggest challenge along his educational path was learning to cut his own path and bounce back when things didn’t work in the lab. “Research is not easy,” he says. “When you go through a year or two without getting any results, you can feel frustrated.” For him, that frustration led to a fruitful change, however; after spending a long time doing experiments without the results he wanted, he changed to working with new materials. “And I flourished,” he says. “Frustration can become an integral part of a research career because you can then see the barrier and figure out how to overcome it.”

For Zhou now, one of the best parts of his job is getting to discuss new technology. That involves not only using his technical skills and background but also his communication skills. “We have to maintain a very strong and healthy relationship with all our suppliers,” he says. And he also has to work with various team members to problem solve. “My role is often as a bridge between different parties,” he says. “Strong, layered communication is key.”