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Movers And Shakers

Chemical engineer Paula T. Hammond on discovery and diversity

Head of MIT’s Chemical Engineering Department, who is building an arsenal of layered drug-delivery systems, wants to take on the toughest challenges

by Bethany Halford
March 20, 2019 | A version of this story appeared in Volume 97, Issue 12


A photo of Paula Hammond.
Credit: Dominick Reuter

To get a glimpse of Paula T. Hammond’s personality, she says, one simply has to enter her office at the Koch Institute for Integrative Cancer Research at the Massachusetts Institute of Technology. Shelves full of texts and journals surround the self-described bookworm’s desk. Splashes of color—something she says has always been a source of delight and inspiration—come from a dozen richly hued glass vases artfully arranged within the office’s large window. The space puts one at ease, something that Hammond also has a knack for doing with her broad smile and friendly manner.

But on paper, Hammond can be intimidating. Not only is she MIT’s David H. Koch Professor in Engineering, but she’s also head of the school’s Chemical Engineering Department. Reflecting her broad interest in both engineering and medicine, she’s part of the MIT Energy Initiative and a founding member of the MIT Institute for Soldier Nanotechnologies. She holds memberships in both the National Academy of Medicine and the National Academy of Engineering. She’s director and cofounder of the medical polymer start-up LayerBio. And in case that isn’t enough, she serves on numerous advisory boards, including C&EN’s.


Hometown: Detroit

Education: BS, chemical engineering, Massachusetts Institute of Technology; MS, chemical engineering, Georgia Institute of Technology; PhD, chemical engineering, MIT

Favorite earworm: Bebop jazz

Preferred reading material: Fiction

Favorite book: Maya Angelou’s I Know Why the Caged Bird Sings

Professional highlight: Meeting President Obama in 2009 when he came to MIT to speak about energy policy.

Key to success: “I’m a planner. I put stuff in my calendar and it happens,” Hammond says. Whether it’s a meeting with a journalist or lunch with her son, it gets inked into her schedule. “That allows me to commit myself entirely to being with who I’m with.”

Hammond’s lab uses electrostatics to build materials from atomically thin polymer layers that have opposite charges. So, for instance, if the first layer is negatively charged, the second layer would be positively charged, followed by a third, negatively charged layer, and so on.

Films and nanoparticles made using this layer-by-layer assembly technique can hold charged species for a vast array of applications, including electrochemical energy storage and drug delivery. For instance, her team has used layer-by-layer films to create nanoparticles that can incorporate drugs and nucleic acids.

“The idea was to use electrostatics, hydrogen bonding, and other interactions to generate polymeric assemblies that would give us unique properties,” Hammond explains. The technique, she says, allows her to combine materials that wouldn’t come together as ordinary polymers. Although she was originally working on systems for energy storage, the water-based assembly process allowed her to incorporate charged entities into the layers. “It naturally became a way we can incorporate biologic materials,” she says.

Hammond says she’s always been interested in solving big problems, and that’s what drew her to cancer research. “As we understand that cancer is more than one disease with many different characteristics, it’s clear that we’re going to need an arsenal of different ways to deliver drugs,” she says. Hammond’s layer-by-layer polymer nanoparticles can deliver drugs specifically to tumors. “The basic idea is that we can control the assembly of these materials systems so that they are responsive to their environment,” she explains. So, for example, the pH of a tumor can trigger a layered nanoparticle to release its cancer-fighting cargo.

What’s more, the materials have other applications in biological systems. They can deliver DNA and RNA. They can deploy their payload to fight infectious diseases and inflammatory conditions, such as cardiovascular disease. “These are really important problems that we want to address, so that’s what gets me excited,” Hammond says.

Hammond’s parentage suggests she was destined for a career in biomedical sciences: her father had a doctorate in biochemistry, and her mother had a master’s in nursing. But Hammond says that although her parents were enthusiastic about science, their primary focus was on education. “Achieving high levels of excellence and seeking your education were key things in my household because both of my parents were the first in their families to get degrees,” she says. “You can tell that there wasn’t an overemphasis on science because one brother is an urban planner and the other is a poet.”

Science as a career choice came to Hammond’s attention when she took chemistry at her all-girls Catholic high school—an environment she thinks helped her flourish in math and science. Hammond’s chemistry teacher was the first woman she had as an instructor for a science class. “I was really fascinated that you could combine molecules to create something that didn’t exist before,” Hammond recalls. She found herself staying after class to help clean up. Her teacher, seeing Hammond’s interest and aptitude for the class, suggested chemical engineering as a career. “I didn’t understand everything about the career, but I decided to check it out,” she says.

Hammond finished high school a year early and, at only 16 years old, began her undergraduate studies at MIT, where she learned how chemical engineers manage reactions via heat and mass transport. “You combine the creative spark of making something—the pure chemistry of it—with the ability to control it and design and generate something that has the properties that you want. Those were all things that made me think chemical engineering is very cool.”

Chemical engineering has continued to hold Hammond’s interest throughout her education and career. She earned master’s and doctoral degrees in the field and then became a professor of chemical engineering at her alma mater. Now, as head of MIT’s Chemical Engineering Department, a position she’s held since 2015, Hammond says she’s focused on what makes her department excellent. One of those things, she says, “is realizing that excellence is gained from diversity.”

Diversity, she says, includes ethnicity, race, gender, and educational and scientific background. “When we are working across this broader range of experiences and perspectives,” she says, “we make inroads into difficult problems because we put together people who have different ways in which they approach problems.”


While Hammond says she sees more diversity among undergraduates, she thinks gains still need to be made among graduate students and the rest of the academic hierarchy. Women are increasingly represented in chemical engineering, she acknowledges, but not as much at higher levels of education and leadership, and there’s still a dearth of underrepresented minorities. As an African American woman, she has experienced this problem firsthand. She says she’s often the only person of color when she attends certain academic conferences.

“One of the key things that we have to work on is the ability to spot talent outside of the framework of the more traditional metrics that we have been using,” Hammond says. “I think that by being conventional and conservative we perhaps walk away feeling more confident about the people we’ve brought in, but we miss shining stars who may excel and haven’t been given an opportunity,” she says.

“There has to be some agility in how we address looking at the potential of a graduate student,” Hammond adds. “We also have to be more active in nurturing and mentoring the talent that we have underfoot—trying to ensure that students don’t get turned away from pursuing careers in which they can excel, getting students into graduate school, getting students to think about the range of research careers where they can have an impact.”

Hammond says her own approach to mentoring is to be encouraging and to be present. “Those are the simplest things. But that, to a large extent, is what mentoring is about,” she says. “Providing the opportunity for students to learn and understand from you what may be helpful for them and also to get a shot of confidence from you about what they’re capable of.”


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