Symposium speakers 2015: Jordan Green

Neuro X is the title and theme for the May 1 symposium hosted by Johns Hopkins Institute for NanoBioTechnology. The event kicks off with a continental breakfast at 8 a.m. in the Owens Auditorium, between CRB I and CRB II on the Johns Hopkins University medical campus. Talks begin at 9 a.m. Posters featuring multidisciplinary research from across many Hopkins divisions and departments will be on display from 1 p.m. to 4 p.m.

One of this year’s speakers is Jordan J. Green, PhD.

Jordan Green, PhD

Jordan Green, PhD

Jordan Green is an associate professor in the Department of Biomedical Engineering at Johns Hopkins University. He graduated from Carnegie Mellon University with a bachelor’s degree in Biomedical Engineering, Chemical Engineering and then attended Massachusetts Institute of Technology to earn his doctorate in Biological Engineering. Green joined the Johns Hopkins faculty in 2008 His research focuses on cellular engineering and nanobiotechnology, with special interests in biomaterials, controlled drug delivery, and gene therapy. The potential of gene therapy and genetic medicine to benefit human health is tremendous as almost all human diseases have a genetic component, from cancer to cardiovascular disease. Methods for drug and gene delivery that are both safe and effective have remained elusive. New insights into understanding and controlling the mechanisms of delivery are required to further advance the field. To accomplish this, Green’s research team is developing a framework where biomaterials and nanoparticles can be rationally designed and computationally modeled. These same biomedical insights can also be used more broadly in the fields of regenerative medicine and nanomedicine.

Dr. Green is working at the chemistry/biology/engineering interface to answer fundamental scientific questions and create innovative technologies and therapeutics that can directly benefit human health. In 2014, Dr. Green was named one of Popular Science magazine’s “Brilliant Ten” list, highlighting young scientists who are revolutionizing their fields. He is also a member of the USA Science and Engineering Festival’s Nifty Fifty, which includes 200 of the most dynamic scientists and engineers in the United States who were selected for their unique ability to inspire the next generation of students to pursue careers in the STEM fields. He and Dr. Alfredo Quiñones-Hinojosa recently won a BioMaryland Center Biotechnology Development Award to advance their work on a biodegradable nanoparticle therapy enabling effective transfection of a patient’s stem cells derived from adipose tissue that are applied directly to the post-operative site of brain cancer.

Additional speakers will be profiled in the next few weeks. To register your poster and for more details visit

For all press inquiries regarding INBT, its faculty and programs, contact Mary Spiro, or 410-516-4802.




Podcast: Shaping polymers for biomedical use

In this edition of the Johns Hopkins Institute for NanoBioTechnology Nanobyte podcast, Hai-Quan Mao, professor of materials science and engineering at Johns Hopkins University, discusses his work with polymers and their potential applications for medicine.

Slide1 In the Mao lab, researchers are using multi-molecule structures called polymers and forming them into different shapes for biomedical applications such as tissue engineering, nerve regeneration, and drug delivery. Mao uses natural models, such virus, as shape templates for designing nanoparticles with specific capabilities.

Listen to the podcast on Mixcloud here.

Visit the Mao Research Group here.

For all press inquiries regarding INBT, its faculty and programs, contact Mary Spiro, or 410-516-4802.

Engineering bacteria for medical uses

According to the National Institutes of Health and Centers for Disease Control, drug resistant pathogens are responsible for 2 million illnesses, 23,000 premature deaths, and an estimated $20 billion dollars in health care costs per year (1,2). The rapid emergence of drug resistant pathogens threatens to undo nearly a century’s worth of biomedical advances, and the situation has become so dire that President Obama has recently made fighting antibiotic resistant pathogens a top national priority.

Engineering Bacteria

Figure 1. Azido modified KDO was used to metabolically glycoengineer the LPS core of E. Coli

Newly emerging molecular engineering techniques may lead the way for next generation therapies designed to attack resistant microbes. One such strategy is metabolic glycoengineering, which is using unnatural monosaccharides to intercept the metabolic machinery of a cell to artificially install chemical “handles” on the surface. These chemical handles can then be exploited by performing reactions known as “click chemistry” to connect almost anything a researcher can think of to the surface of any cell.

Some of the most important structures of bacteria such as the peptidoglycan layer, lipopolysaccharides (LPS), teichoic acids, and capsule are comprised of extensive amounts of carbohydrates. Using glycoengineering, a physician may one day be able engineer those structures with unnatural monosaccharides to disrupt the adhesive properties, directly image, or target drugs to bacteria in a species specific manner–an unprecedented level of selectivity currently unachievable with our current regimen of antibiotics (Fig. 1).

For further reading:

About the Author: Christopher Saeui is a fourth year Biomedical Engineering PhD student in the Kevin J. Yarema Laboratory for Cell and Carbohydrate Engineering studying the epigenetic and metabolic mechanisms that alter glycosylation in cancer.


REU student profile: Christopher Glover

Christopher Glover is a rising senior in bioengineering at the University of Missouri. He worked this summer as an REU intern in the laboratory of professor Jeff Tza-Huei Wang, who has joint appointments in mechanical engineering, biomedical engineering and oncology. The Research Experience for Undergraduates, hosted by Johns Hopkins Institute for NanoBioTechnology, attracts nearly 800 undergraduate applicants for just 10 research positions.

Christopher Glover

Christopher Glover

Christopher’s project involved a proof-of-concept experiment to test a device used to digitally sort and amplify DNA samples.

The device consists of a silicone chip imprinted with 3,000 tiny wells to contain DNA. A thermoplastic lid covers the top of the chip to keep the DNA in place in the wells. After a segment of DNA is added to the chip, the number of copies of that DNA segment is amplified using a device called a thermal cycler. “The goal is to either get zero or one copy of the DNA segment in each well, which makes the device “digital,” he said.

“We aren’t concerned about the type of DNA we are amplifying but just to see if it will work,” Christopher said. “This could be used for medical screening where a specific allele could be detected within a gene to see if someone is more susceptible to getting a disease,” he said.

Christopher said that working in the Wang lab has helped him learn much more about nanotechnology than he had previously known. His future plans include earning a PhD in biomedical engineering.

For all press inquiries regarding INBT, its faculty and programs, contact Mary Spiro, or 410-516-4802.

REU student profile: Rebecca Majewski

DNA, the genetic sequence that tells cells what proteins to manufacture, typically resides inside the nucleus of a cell, but not always. Rebecca Majewski is studying the uptake of DNA into cell nuclei using a different polymer chains. Rebecca is a rising senior in BioMolecular Engineering from the Milwaukee School of Engineering and is working as a summer intern in the Johns Hopkins Institute for Nanobiotechnology’s REU program.

“We are interested in how much of the DNA with the polyplex can get into the nucleus,” she said, but explains that DNA associated outside of the nucleus can cause false higher measurements.

Rebecca Majewski. Photo by Mary Spiro

Rebecca Majewski. Photo by Mary Spiro

Rebecca is washing the cells with the nuclei to get rid of DNA outside the nucleus and then comparing the measurement of uptake of the DNA by the cell versus the measurement of the uptake of DNA by the nucleus.

“We are interested in what DNA gets inserted into the nucleus because that is what is ultimately expressed. It is important to find out how much makes it to the final destination and then is expressed. The goal of this work is to test different polymer chains to see which one actually does the better job of getting the DNA into the nucleus,” she said.

Rebecca works alongside PhD students and postdoctoral fellows in the biomedical engineering lab of Jordan Green lab at the Johns Hopkins School of Medicine. She says she highly values the opportunity for a research experience through INBT’s REU because her undergraduate institution does not train graduate students.

For all press inquiries regarding INBT, its faculty and programs, contact Mary Spiro, or 410-516-4802.

REU student profile: Ian Reucroft

Sitting at what looks like a pottery wheeled turned on its side, Ian Reucroft is using a method called electrospinning to create a nano-scale polymer fiber embedded with a drug that encourages nerve growth. The strand is barely visible to the eye, but the resulting fibers resemble spider web.

Ian Reucroft, a rising junior in Biomedical Engineering at Rutgers University, is working in the medical school campus laboratory of Hai-Quan Mao, professor of materials sciences and engineering at Johns Hopkins University. He is part of Johns Hopkins Institute for NanoBioTechnology’s summer REU, or research experience for undergraduates program.

Ian Reucroft in the Mao lab. Photo by Mary Spiro.

Ian Reucroft in the Mao lab. Photo by Mary Spiro.

“We are developing a material to help regrow nerves, either in central or peripheral nervous systems,” said Ian. One method of doing that he explained is to make nanofibers and incorporating a drug into those fibers, drugs that promote neuronic growth or cell survival or various other beneficial qualities. The Mao lab is looking into a relatively new and not well-studied drug called Sunitinib that promotes neuronal survival.

“We make a solution of the component to make the fiber, which is this case is polylactic acid (PLA), and the drug, which I have to dissolve into the solution,” Ian said. Although the drug seems to remain stable in solution, one of the challenges Ian has faced has been improving the distribution of the drug along the fiber.

This is Ian’s first experience with electrospinning but not his first time conducting research. He plans to pursue a PhD in biomedical engineering and remain in academia.

For all press inquiries regarding INBT, its faculty and programs, contact Mary Spiro, or 410-516-4802.

Konstantopoulos to present distinguished lecture on tumor cell migration

Biomedical Engineering 8 5 x 11 4-7Biomedical Engineering 8 5 x 11 4-7Biomedical Engineering 8 5 x 11 4-7Professor and Chair of the Department of Chemical and Biomolecular Engineering, Konstantinos Konstantopoulos will present a distinguished lecture for the Department of Biomedical Engineering on Monday, April 7 at 4 p.m. in the Mason Hall Auditorium on the Homewood campus of Johns Hopkins University.  His talk. “Joining Forces with Biology: A Bioengineering Perspective on Tumor Cell Migration,” will reveal some of his laboratory’s current findings on metastasis. The talk is free and open the Johns Hopkins University community. Refreshments follow the lecture.

Here’s the abstract of his talk:

“Understanding the mechanisms of cell migration is a fundamental question in cell, developmental and cancer biology. Unraveling key, physiologically relevant motility mechanisms is also crucial for developing technologies that can control, manipulate, promote or stop cell migration in vivo. Much of what we know about the mechanisms of cell migration stems from in vitro studies using two-dimensional (2D) surfaces. Cell locomotion in 2D is driven by cycles of actin protrusion, integrin-mediated adhesion and myosin-dependent contraction. A major pitfall of 2D assays is that they fail to account for the physical confinement that cells  encounter within the physiological tissue environment. The seminar will challenge the conventional wisdom regarding cell motility mechanisms, and show that migration through physically constricted spaces does not require beta1 integrin dependent adhesion or myosin contractility. Importantly, confined migration persists even when filamentous actin is disrupted. This seminar will also discuss a novel mechanism of confined cell migration based on an osmotic en

Nanotechnology for gene therapy

Editor’s Note: The following is a summary of one of the talks from the 2013 Nano-bio Symposium hosted by Johns Hopkins Institute for NanoBioTechnology held May 17. This summary was written by Randall Meyer, a doctoral candidate in the biomedical engineering and a member of the Cancer Nanotechnology Training Center. Look for other symposium summaries on the INBT blog.

One of the key features of nanotechnology is its wide range of applicability across multiple biological scenarios ranging from gene therapy to immune system modulation. Jordan Green, an assistant professor of Biomedical Engineering at Johns Hopkins University, summarized some of the fascinating applications of nanotechnology on which his laboratory has been working. Green is an INBT affiliated faculty member.

One of the Green lab projects involves the design and implementation of nanoparticle based vectors for delivery of genetic material to the cell. Green demonstrated how these particles could be used to deliver DNA and induce expression of a desired gene, or small interfering RNA (siRNA) to silence the expression of a target gene. These genetic therapeutics are being developed to target a wide variety of retinal diseases and cancers.

Jordan Green (Photo by Marty Katz)

Jordan Green (Photo by Marty Katz)


As opposed to viral based vectors for gene therapy, nonviral vectors such as nanoparticles are safer, more flexible in their range of cellular targets, and can carry larger cargoes than viruses, Green explained.


Another project in the Green lab involves the development of micro and nano dimensional artificial antigen presenting cells (aAPCs) for cancer immunotherapy. These aAPCs mimic the natural signals that killer T-cells receive when there is an invader (bacteria, virus, cancer cell, etc.) in the body. The Green lab is currently working with these particles to stimulate the immune system to fight melanoma.


Green Group

Nanoscale scaffolds spur stem cells to cartilage repair

Scanning electron micrographs showing chondroitin sulfate (CS) and poly(vinyl alcohol)-methacrylate (PVA) nanofibers after electrospinning and processing to render the nanofiber scaffolds water-insoluble. Image by Jeannine Coburn/JHU first appeared in PNAS.

A spun 3-D scaffold of nanofibers did a better job of producing larger quantities of and a more durable type of the cartilage protein than flat, 2-D sheets of fibers did. 

Johns Hopkins tissue engineers have used tiny, artificial fiber scaffolds thousands of times smaller than a human hair to help coax stem cells into developing into cartilage, the shock-absorbing lining of elbows and knees that often wears thin from injury or age.

Reporting online June 4 in the Proceedings of the National Academy of Sciences, investigators say they have produced an important component of cartilage in both laboratory and animal models. While the findings are still years away from use in people, the researchers say the results hold promise for devising new techniques to help the millions who endure joint pain.

“Joint pain affects the quality of life of millions of people. Rather than just patching the problem with short-term fixes, like surgical procedures such as microfracture, we’re building a temporary template that mimics the cartilage cell’s natural environment, and taking advantage of nature’s signals to biologically repair cartilage damage,” says Jennifer Elisseeff, Ph.D., Jules Stein Professor of Ophthalmology and director of the Translational Tissue Engineering Center at the Johns Hopkins University School of Medicine. Elisseeff is also an affiliated faculty member of Johns Hopkins Institute for NanoBioTechnology.

Unlike skin, cartilage can’t repair itself when damaged. For the last decade, Elisseeff’s team has been trying to better understand the development and growth of cartilage cells called chondrocytes, while also trying to build scaffolding that mimics the cartilage cell environment and generates new cartilage tissue. This environment is a three-dimensional mix of protein fibers and gel that provides support to connective tissue throughout the body, as well as physical and biological cues for cells to grow and differentiate.

In the laboratory, the researchers created a nanofiber-based network using a process called electrospinning, which entails shooting a polymer stream onto a charged platform, and added chondroitin sulfate — a compound commonly found in many joint supplements — to serve as a growth trigger. After characterizing the fibers, they made a number of different scaffolds from either spun polymer or spun polymer plus chondroitin. They then used goat bone marrow-derived stem cells (a widely used model) and seeded them in various scaffolds to see how stem cells responded to the material.

Elisseeff and her team watched the cells grow and found that compared to cells growing without scaffold, these cells developed into more voluminous, cartilage-like tissue.

“The nanofibers provided a platform where a larger volume of tissue could be produced,” says Elisseeff, adding that three-dimensional nanofiber scaffolds were more useful than the more common nanofiber sheets for studying cartilage defects in humans.

The investigators then tested their system in an animal model. They implanted the nanofiber scaffolds into damaged cartilage in the knees of rats, and compared the results to damaged cartilage in knees left alone.

They found that the use of the nanofiber scaffolds improved tissue development and repair as measured by the production of collagen, a component of cartilage. The nanofiber scaffolds resulted in greater production of a more durable type of collagen, which is usually lacking in surgically repaired cartilage tissue. In rats, for example, they found that the limbs with damaged cartilage treated with nanofiber scaffolds generated a higher percentage of the more durable collagen (type 2) than those damaged areas that were left untreated.

“Whereas scaffolds are generally pretty good at regenerating cartilage protein components in cartilage repair, there is often a lot of scar tissue-related type 1 collagen produced, which isn’t as strong,” says Elisseeff. “We found that our system generated more type 2 collagen, which ensures that cartilage lasts longer.”

“Creating a nanofiber network that enables us to more equally distribute cells and more closely mirror the actual cartilage extracellular environment are important advances in our work and in the field. These results are very promising,” she says.

Other authors included Jeannine M. Coburn, Matthew Gibson, Sean Monagle and Zachary Patterson, all from The Johns Hopkins University.

From a press release by Audrey Huang.


It’s a small world: Micro/nanotechnology in regenerative medicine and cancer

Sageeta Bhatia

Nanotechnology, regenerative medicine and cancer will be the topic of a special biomedical engineering seminar on March 6 at 3 p.m. in the Darner Conference Room, Ross Building, Room G007 at the Johns Hopkins School of Medicine. Speaker Sangeeta Bhatia, MD, PhD, director, of the Laboratory for Multiscale Regenerative Technologies at Massachusetts Institute of Technology will present “It’s a small world: Micro/Nanotechnology in Regenerative Medicine and Cancer. ” She will discuss the role of micro and nanotechnology for mimicking, monitoring and perturbing the tissue microenvironment.

“I will present our work on reconstructing normal liver microenvironments using microtechnology, biomaterials and induced pluripotent stem cells as well as our work on normalizing diseased cancer microenvironments using both inorganic and organic nano materials,” Bhatia noted in an announcement.  Bhatia is a professor of Health Sciences and Technology and professor of Electrical Engineering and Computer Science at MIT.

The talk is hosted by associate professor of Materials Science and Engineering and affiliated faculty member of the Institute for NanoBioTechnology Hai-Quan Mao. The event is free and open to the Johns Hopkins Community. Refreshments will be served.