Profile: Terrence Dobrowsky, PhD student

Terrence Dobrowsky has his hands full working in two labs at Johns Hopkins: Denis Wirtz (chemical and biomolecular engineering) and Robert Siliciano (rheumatology and molecular biology and genetics). Dobrowsky moves between the East Baltimore and Homewood campuses in order to investigate binding kinetics for HIV envelope proteins in living cells.

After completing an undergraduate degree in chemical engineering at Notre Dame, Dobrowsky chose to pursue his PhD in chemical and biomolecular engineering at Hopkins to explore research connections between engineering and biology.

“In the past five years, universities around the country have renamed their departments ‘chemical and biological engineering’ but I found that many of them are not really doing bioengineering,“ he says. “I’m glad I chose Hopkins because I feel the experience I’m getting here as a student in the Howard Hughes Medical Institute Graduate Training Program in Nanotechnology for Biology and Medicine will truly prepare me for a career in this interdisciplinary field.“

Dobrowsky says he enjoys working in “two worlds“ with different ways of approaching a problem. “In attempting to affect a system as complicated as HIV infection, it just makes sense to understand the biology involved as well as relevant physical and chemical interactions.“

Dobrowsky acknowledges that work in the lab for 60 hours or so each week can sometimes get tedious, but even then he wouldn’t want to be anywhere else. “When your experiment works, you have a brief moment of enlightenment that inspires you to keep going,“ he says.

Seminar: Designing DNA-Binding Proteins

On Dec. 6, Carl O. Pabo presented a talk on the structure and design of DNA-binding proteins to the Johns Hopkins Department of Biophysics and Biophysical Chemistry.

Pabo, a visiting professor at Harvard University, discovered that several proteins involved in transcription have zinc fingers that allow them to bind to DNA. Pabo began much of his groundbreaking work on protein-DNA interaction while a faculty member at Hopkins from 1982 to 1991.

Pabo discussed his initial crystallographic studies that focused on major DNA-binding proteins. “The discovery of more areas of surface contact was like finding more lottery tickets,“ he said. “We had found more chances to win.“

Pabo said it was clear to him after initial investigations of protein-DNA crystal structures that there is no “simple code“ for recognition. His team pursued geometric analysis and computational modeling of spatial relationships based on the hypothesis that the way a protein approaches DNA may determine the ability for interactions. The group found a wide variety of docking arrangements but discovered the average arrangement had a similar ridge structure.

Pabo then focused on designing new DNA-binding proteins based on observations. His work on engineered zinc fingers, the most abundant and versatile DNA-binding motif in nature, simulated a very complex interaction with diverse applications including targeted DNA cleaving, gene correction, and genome editing.

His current work continues to explore the limits of specificity in zinc finger-DNA interactions for further work in gene editing.

Bacteria Combined with Chemo Helps Fight Cancer

Clostridium novyi bacteria.
Clostridium novyi bacteria. Credit: CDC

A new mouse study at the Johns Hopkins Kimmel Cancer Center demonstrates that combining liposome-encapsulated chemotherapy drugs with bacterial therapy dramatically improves the prospects for cancer eradication. [Read more...]

Biosensor Targets Retina Cells

Layered anatomy of the DNA tethered nanoparticle.
Layered anatomy of the DNA tethered nanoparticle. Credit: Tarl Prow and Gerard A. Lutty / JHU

Researchers affiliated with the Institute for NanoBioTechnology at Johns Hopkins have created a new biosensor that treats damaged cells in the eye’s retina with targeted gene therapy. The approach also may be useful in designing treatments for diseases such as cancer and psoriasis, according to the researchers, since it targets uncontrolled growth of new blood vessels.

Led by cell biologist Gerard Lutty and Research Associate Tarl Prow of the Wilmer Eye Institute at Johns Hopkins, the project includes collaborations with chemists, pathologists, and biomedical engineers.

The biosensor is a DNA promoter sequence tethered to multi-layered magnetic nanoparticles. When activated by oxidative stress, the biosensor allows the cell to regulate its own therapeutic gene expression and quickly respond to damage caused by free radicals. [Read more...]

Assessing Nanotech Risk

Imaging particle distribution in the lungs. John Links / JHU
Imaging particle distribution in the lungs. Credit: John Links / JHU

From drug delivery tools to environmental sensors to “super“ cleaners, the very small products resulting from nanotechnology are demonstrating big potential to improve the quality of life. Researchers at the Institute for NanoBioTechnology (INBT) are involved in both developing new nanotechnologies and analyzing their potential risks.

At the nanoscale, a material’s physical and chemical properties – such as strength, optical absorption, and electrical conductivity – change. These very small materials with different properties are enabling new technologies like nano-sized capsules that can deliver medicine directly to damaged cells in the body. [Read more...]

Life, Synthetically

Piecing together DNA - Sarah Richardson, JHU
The Synthetic Yeast Project is piecing together yeast DNA to create the organism from the bottom up. Credit: Sarah Richardson/Johns Hopkins University

Johns Hopkins biomedical engineer Joel Bader has a lofty goal – keeping a yeast organism alive while painstakingly replacing its DNA piece by piece to construct it synthetically.

Synthetic biology is a relatively new field that aims to make it easier to design and build useful organisms by addressing complex biological questions.

We are working to synthesize yeast chromosomes, and eventually the genome, using a ‘bottom up’ approach,“ says Bader, who is affiliated with the Institute for NanoBioTechnology at Johns Hopkins. [Read more...]

Seminar: Adding Function to Nano

On Oct. 18, Dotsevi Y. Sogah presented a talk on the functionalization of nanoparticles to the Johns Hopkins Department of Materials Science and Engineering. Sogah, a chemistry and chemical biology professor at Cornell University, helped invent group transfer polymerization during previous work at DuPont.

Sogah discussed his group’s research in developing nanocomposites and protein-based polymers. He said he was recently “bitten by the nano bug,“ and is now developing functionalized nanoparticles. “We didn’t just wake up one morning and decide to work on nanoparticles,“ he said. “We had made discoveries about growing polymer chains on silicate from two directions and thought we could make a difference in this area.“ His group aims to apply knowledge of polymerization chemistry to nanotechnology.

Sogah and collaborators have successfully functionalized nanoparticles and carbon nanotubes with biotin by attaching a chemical initiator to the nanoparticle’s surface. Using the streptavidin protein, the researchers have created a template for layered construction of the nanomaterials. The end result is well-dispersed and layered polymer-functionalized nanoparticles.

Incubating Tech Entrepreneurs

For technology entrepreneurs interested in starting a business, the Maryland Technology Development Corporation (TEDCO) supports business incubators in Baltimore and around the state.

The following incubators are located within 10 miles of a Johns Hopkins research institution:

Emerging Technology Center at Canton
2400 Boston Street, Suite 300
Baltimore, MD 21224
http://www.etcbaltimore.com

Emerging Technology Center at Johns Hopkins Eastern
1101 East 33rd Street
Baltimore, MD 21228
http://www.etcbaltimore.com

Techcenter@UMBC
1450 South Rolling Road
Baltimore, MD 21227
http://www.umbc.edu/Business/Research/index.html

Neotech Incubator
9250 Bendix Road
Columbia, MD 21045
http://www.hceda.org/thecenter/center.html

For more information about business incubation in Maryland and TEDCO programs for technology entrepreneurs, visit http://www.marylandtedco.org.

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 inbt@jhu.edu for consideration. Include a caption for each image and your name, lab group, and contact information.

Submit Proposals with INBT

INBT faculty have the opportunity to submit nano-bio related proposals through INBT and receive 10 percent return of indirect costs to the principal investigators. Contact Sue Porterfield, INBT Administrative Manager, by email at sporterfield@jhu.edu or phone at 410-516-3423 for information and guidelines.