Profile: Kate Stebe, Department of Chemical and Biomolecular Engineering

Stebe's research interests include the engineering of fluid interfaces, nanomaterials, and microfluidics.Stebe’s research interests include the engineering of fluid interfaces, nanomaterials, and microfluidics.

Kate Stebe is chair of the department of Chemical & Biomolecular Engineering at Johns Hopkins University and program director for one of INBT’s graduate degree programs. The following interview was previously published in Johns Hopkins Engineering, the magazine of the Johns Hopkins Whiting School of Engineering, winter 2007 (PDF).

Last July, professor Kate Stebe became chair of the Whiting School’s Department of Chemical and Biomolecular Engineering, a rapidly growing department with a faculty of 13. A member of the engineering school’s faculty since 1991, Stebe has served on the university’s Academic Council and was previously director of her department’s graduate program. Her research interests include the engineering of fluid interfaces, nanomaterials, and microfluidics. She holds a joint appointment with the Department of Biomedical Engineering and secondary appointments in Materials Science and Engineering and Mechanical Engineering. At the start of the fall semester, the magazine’s Abby Lattes sat down with Stebe, to talk about her vision for the future of Chemical and Biomolecular Engineering.

ChemBE is a fast-growing department. Can you discuss that growth and how you’re managing it?

This year alone we have 120 freshmen and have increased our graduate student yield by 100 percent— from 8 to 16 new graduate students. At the graduate level, we introduced a revised curriculum this past fall. We’ve returned to the fundamental courses in each discipline and amended them to include more timely examples. We’ve added required non-classical courses in topics such as interfaces and materials and others that emphasize opportunities and techniques in biomolecular engineering. At the undergraduate level, we’ve also seen explosive growth. This growth is due in part to students’ understanding of the scope of the problems we attack and their relevance to bio-related industries, such as protein-based pharmaceuticals and lab-on-a-chip devices. Meeting the challenges this growth presents while honoring our commitment to quality education will require care, focus, creativity, and plain old hard work.

In 2002 the department changed its name from Chemical Engineering to Chemical and Biomolecular Engineering. What prompted that change?

This department is built on a clear understanding of our strengths. We were a chemical engineering department with half of our faculty working as applied scientists on biological themes. Our redefinition was a recognition of this strength and where we knew we could make the greatest impact. We have two centers of excellence in the
Department — biomolecular engineering and our deep expertise in interfaces. We’re configured very tightly around these areas and poised to do fundamental work at their intersection.

How do you view advances in the field and your role as department chair?

Chemical engineering expertise in interfaces, made possible through our ability to control surfaces at the molecular level, now has important applications in micro- or nano-fluidics devices, micro mechanical electrical systems, and controlling the interactions of nanomaterials. Since the early 1990s, there’s been a lot of elegant work done by chemical engineers in bio-related problems—where complex ideas about chemical systems far from equilibrium are applied to our understanding of synthesis in cells and cell-cell interactions, for example. There are important applications to this work that range from using cells to produce chemical products to understanding plaque formation in heart disease or metastatic events in cancer. As a department, we all took part in the process of redefining who we are and have a highly unified vision about the direction in which we’re going. Now I’m in the driver’s seat to implement the vision.

What is the most fundamental element to the program’s success?

Our faculty. They are individual experts in their fields and highly integrated throughout the department and across other departments, divisions, and research centers and institutes. They’re young and ready to move in a common direction to pull us forward. This balance of individual expertise and shared vision makes the department a special place.

What message do you give to female students looking at careers in academia?

The life balance issues will always be there for women and I talk about this with my students. For example, when I go home, I’m “Mom,“ and turn my attention to my 5-year-old daughter. A tremendous advantage to working in academia is that we’re measured according to whether or not we’re productive and creative, not the hours we’ve logged. It’s an incredibly demanding profession, but it is also flexible. I don’t know if the opportunities created by that flexibility are always made clear to young people of either gender considering academic careers. It is possible to make it all work and it can be very rewarding.

What’s on the horizon?

We’re defining what the field should be. We’re attacking problems on the molecular and nano scale. We are poised to make a strong contribution to the fundamental issues in our field. It’s an exciting time in our department.

More info:

Nanomedicine Research Day at the University of Maryland

The Center for Nanomedicine and Cellular Delivery at the University of Maryland School of Pharmacy will organize their first Nanomedicine Research Day on March 23, 2007. The purpose of this symposium is to provide an overview of the research activities of the center and the local/regional nanomedicine community in an attempt to foster interactions in this new area of research.

Download the complete program (PDF format).

Visit the website of the Center for Nanomedicine at UMD.

Cellular and Molecular Dynamics – Winning Proposals Announced

After soliciting and reviewing proposals in one of INBT’s core research areas, Cellular & Molecular Dynamics, INBT recently awarded a total of $75,000 in seed funding, or $25,000 for each project, to three multi-disciplinary research teams at Johns Hopkins. The awards will jumpstart new investigations into nanobiotechnology.

Winning Proposals:

1) Andre Levchenko (Biomedical Eng) and Jin Zhang (Pharmacology and Neuroscience) “Nano- and micro-scale analysis of PKA regulation of cell locomotion”

2) Y. C. Lee (Biology), Hai-Quan Mao (Materials Science & Eng) and Shau-Ku Huang (Medicine) “Glyco-nanoparticles targeting dendritic cells for enhanced immune tolerance”

3) Chien-Fu Hung (Pathology) and Justin Hanes (Chemical Eng) “Polymeric nanoparticle drug delivery systems for the development of an immunogenic ovarian tumor cell-based vaccine”

Nanobiotechnologist – An interview with Peter Searson

In a recent interview conducted by Cogito, Peter Searson, JHU professor of Materials Science & Engineering and Director of the Institute for NanoBioTechnology, gives insightful answers to questions about his work, INBT, and nanobiotechnology in general.

What’s the coolest thing that’s happened at the Institute so far this year?

“…One of the most exciting things for me is that we have established many new collaborations between researchers in engineering/physical sciences and life sciences / medicine. I am convinced that we will start to see some incredible new technologies as a result of these collaborations in the future…” says Searson.

Read the full interview here;

Interview with Peter Searson on

Coated Nanoparticles Slip Through Mucus

Researchers at Johns Hopkins University have discovered a way to make larger nanoparticles slip through mucus. The secret is to coat them with the molecule polyethylene glycol (PEG), says Justin Hanes, Associate Professor of Chemical and Biomolecular Engineering and member of the Institute for NanoBiotechnology at Johns Hopkins. “This method of drug delivery could be used for literally most pharmaceuticals that are swallowed”, according to Hanes… >> read more on Headlines at Hopkins

also covered on:

Genetic Insights into Parkinsons Disease

diagram demonstrates how the LRRK2 gene is related to kinase activity and neural cell toxicity.
The diagram demonstrates how the LRRK2 gene is related to kinase activity and neural cell toxicity. Credit: Ted M. Dawson/Johns Hopkins

A chronic disorder of the central nervous system, Parkinson’s Disease (PD) is currently treated with drugs that may slow progression of its physical symptoms – including tremors, impaired balance, and rigidity – but lack significant effect on the progression of the disease itself. Ted Dawson and members of his research team at Johns Hopkins have been at the forefront of research identifying the role and function of genes in the pathogenesis of PD for years. [Read more…]

Environmental Impact of Carbon Nanotubes

image of vials containing carbon nanotubes.
The vials contain similar concentrations of carbon nanotubes in water with different levels of oxidation, displayed as a percentage on the vial’s cap. Credit: Billy Smith/Johns Hopkins

Carbon nanotubes (CNTs) are among the most widely manufactured and commercialized nanomaterials, but what happens to them in the environment? Environmental engineer William Ball and surface chemist Howard Fairbrother at Johns Hopkins recently received funding from INBT to investigate the fate and effects of CNTs in aquatic environments.

“The production and use of CNTs has skyrocketed as their commercial applications, including flat panel displays, biomedical imaging, and targeted drug delivery, grow,“ says Ball. “But research on the health and environmental consequences of these engineered materials has unfortunately lagged behind commercial advancement.“

Concern about the potential impacts of CNTs and other nanoscale materials are being raised by environmental scientists because the roles of the materials’ chemical and physical properties on environmental fate and effect are not fully understood. Such properties are sometimes deliberately altered to enable manipulation or can be incidentally altered by natural environmental processes after the particles are released, says Ball. Thus, scientists do not yet know how these new materials interact with toxic contaminants and how they behave in and move through the natural environment.

Ball and Fairbrother began collaborating on the surface chemistry and environmental fate of black carbon a few years ago. Not long into their work together, the two started discussing CNTs. When INBT announced seed funding to jumpstart new projects at Hopkins focused on health and environmental issues of nanotechnology last fall, Ball and Fairbrother applied and received $25,000 to initiate a study and fund post-doctoral researcher Huyn-Hee Cho.

Their study is focused on the effects that surface oxidation and adsorbed natural organic matter exert on the properties of CNTs in aquatic environments.

“The surface chemistry of a carbon nanotube is particularly important in determining its stability in water,“ says Fairbrother. “As oxygen-containing functional groups (e.g. hydroxyl, carbonyl, and carboxylic) are added to its surface, the carbon nanotube’s stability in aquatic environments increases. We expect the effects of surface oxidation to have profound implications for the fate, transport, and environmental impact of carbon nanotubes.“

The researchers are looking at how CNTs behave in water, to what extent they aggregate, and to what extent they harbor and interact with toxic contaminants. Lab experiments include functionalizing CNTs through surface oxidation and exposing the materials to natural organic matter to test adsorption. The effect of surface oxidation and natural organic matter on the sorption of pollutants is also being studied using new sorption methods for finely dispersed black carbon materials developed by Ball’s research group.

Ball is professor of environmental engineering at Johns Hopkins and faculty member of the following university centers and institutes: Institute for NanoBioTechnology; Center for Contaminant Transport, Fate and Remediation; Center for Hazardous Substances in Urban Environments; Center for Applied and Environmental Fluid Mechanics; and Center for Water and Health.

Fairbrother is associate professor of chemistry and materials science and engineering at Johns Hopkins and faculty member of the Institute for NanoBioTechnology and the Center for Hazardous Substances in Urban Environments.

Nanofiber Scaffolds Grow Neural Stem Cells

Fluorescence microscopic image of rat neural stem cells
Fluorescence microscopic image shows rat neural stem cells (blue with DAPI nuclear staining) cultured on functionalized nanofiber scaffold (green). Credit: G. Christopherson, X.Y. Liu, H.J. Song, and H.Q. Mao/Johns Hopkins

Cells can be controlled in culture, but once they are placed inside the body their environment – and the probability of their survival and growth – changes. Neuroscientist Hongjun Song and materials engineer Hai-Quan Mao at Johns Hopkins are investigating nanofiber scaffolds that can create artificial 3-D local environments for neural stem cells.

Song and Mao have developed nanofibers to which they can attach adult neural stem cells by first binding bioreactive proteins. The nanofiber scaffolds provide an environment for neural stem cells to grow, proliferate, and develop.

“One of the benefits of using nanofibers is the ability to have successful cell self-renewal without requiring a high concentration of growth factors,“ says Song.

The collaborators are exploring new projects together and have recently started to expand their initial work to include embryonic stem cells. Song says stem cell science has much to offer biology. “By studying the mechanisms of stem cell behavior, we can learn how cells do it: what is happening in the body, how an animal can start with one cell type and develop specificity,“ he explains.

“Eventually, stem cells will be very important for treating disease using cell replacement therapy, but more immediately stem cells offer the opportunity to model human disease and find ways to screen for therapeutic drugs to treat the disease.“

Song is assistant professor of neurology and neuroscience, faculty member of the Institute for Cell Engineering and the Institute for NanoBioTechnology at Johns Hopkins, and member of the Johns Hopkins Stem Cell Policy and Ethics Program. Mao is assistant professor of materials science and engineering and faculty member of the Whitaker Biomedical Engineering Institute and the Institute for NanoBioTechnology at Johns Hopkins.

Student Prizes for Cool NanoBio Images

INBT will award one $25 gift certificate each month for a “cool“ nanobio research image, illustration, or graphic submitted by an undergraduate student, graduate student, or post-doctoral fellow.

Images must be the student or post-doc’s original material and it must be relevant to a current nanobiotechnology research project. Each student and post-doc can submit up to three images per month. Images will be judged on visual appeal and depiction of scientific findings. INBT staff will choose one image each month to be featured on the INBT website with credit to the student or post-doc, who will also receive a $25 gift certificate for Barnes & Noble bookstore.

Please submit your image(s) by the 1st of each month to for consideration. Include a caption for each image and your name, lab group, and contact information.

Spring Symposium

INBT will hold a spring symposium on Friday, April 27, 2007 at the Homewood Campus of Johns Hopkins University. Events will include nanobiotechnology research presentations, a student poster session, and more. Additional details will be announced in coming weeks.

Update (2-22-2007):

More details here.