Finding new tasks for the disruptive proteins in bee venom

When a bee stings you, it leaves its stinger within your body releasing a peptide toxin called melittin. Melittin is toxic to cells because it is able to insert and bind to the cell membrane, which destabilizes the membrane.

Melittin is able to interact with the hydrophobic lipid layer of the cell membrane by forming unique helixes where hydrogen bonding occurs between both peptides. Consequently, charged (polar) amino acid residues are generally not observed in such proteins and pH can change the binding affinity. Such proteins are called membrane active proteins (MAPs).

Now this is not good for your bee-stung cells, but researchers are looking to repurpose nature’s disruptive proteins as anti-microbial drugs, cancer therapeutics, and HIV drugs. Specifically, researchers in the Kalina Hristova lab in the Department of Materials Science and Engineering at Johns Hopkins are engineering proteins based off of the melittin protein.

Figure 1: Membrane Active Peptide Schematic (Source:

Figure 1: Membrane Active Peptide Schematic (Source:

The Hristova lab researchers study their developed MAPs by using lab-produced vesicles from phosphatidylcholine (the major component of a cell membrane). They use the natural fluorescence from tryptophan (which increases in a hydrophobic environment), and circular dichroism spectroscopy (which is able to detect the chiral structure of proteins) to verify the peptide’s interactions with the vesicles, and what affinity they will bind.

About the author: John Hickey is a second year Biomedical Engineering PhD candidate in the Jon Schneck lab researching the use of different biomaterials for immunotherapies and microfluidics in identifying rare immune cells.

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.


What is microfluidics?

Microfluidics continues to find applications in many fields as researchers are realizing the benefits of scaling down to micron scales. This has implications in saving money from reagents and time from completing lengthy assays.

It also means that researchers are able to control experimental parameters at the micron scale more effectively, and use the fluidic flow to provide a dynamic environment. Applications for these devices include, but are not limited to, examples such as pathogen and cancer detection from blood, forming microparticles, studying antibiotic drug-resistant bacteria, understanding nanoparticle blood transport, and observation of the kinetics of chemical reactions.


Figure 1: A picture of a general microfluidic device. Source:

One reason that microfluidics has become so widespread is that the process to develop and create these devices is relatively simple and inexpensive. The process, called photolithography, is based off of a technology developed for the semiconductor industry in developing small features for circuits.

Photolithography uses special polymers that are reactive to certain wavelengths of light to create the forms used to make the device. Then another polymer, typically polydimethylsiloxane (PDMS), is poured into the casted photo-cured polymer mold to produce the microfluidic device. Many devices can be made from this mold and used in research and diagnostics for low-volume, high-throughput experiments.

John Hickey is a second year Biomedical Engineering PhD candidate in the Jon Schneck lab researching the use of different biomaterials for immunotherapies and microfluidics in identifying rare immune cells.

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

Chakravarthy: edging toward breakthroughs in nanomedicine

Krishnan Chakravarthy is a resident physician in the Department of Anesthesiology and Critical Care Medicine at the Johns Hopkins Hospital. He is also the founder of a company called NanoAxis. He is seeking potential faculty collaborators through Johns Hopkins Institute for NanoBioTechnology, where he is a recently affiliated faculty member.

Krishnan Chakravarthy

Krishnan Chakravarthy

Chakravarthy launched NanoAxis in 2009 while earning an MD and PhD at SUNY Buffalo. He won the Henry A. Panasci Jr. Technology Entrepreneurship Competition sponsored by the University of Buffalo School of Management with a business plan for creating a new drug delivery mode for seasonal and pandemic flu using quantum dots and gold nano particles.

He is the remaining founder and owner of NanoAxis and says the company has grown significantly since 2009. NanoAxis now has active labs and collaborators both nationally and internationally. The company is now taking root in Maryland, and Chakravarthy says he is actively working on collaborating with local biotech businesses in the area.

INBT: Can you briefly summarize your company’s main goals?

KC: At inception, we were primarily interested as a business to commercialize quantum dot technology for various industrial applications. Over the course of six years, our business goals have shifted from large-scale nano materials manufacturing to being the world leader in developing paradigm-shifting technologies in the field of nano medicine. For us, this comprises nano particle enabled advances in drug delivery and smart design point-of-care devices using nanotechnology.

At present, we have four main preclinical candidates that we are working on with the eventual goal of beginning FDA clinical trials. One project involves a novel antiviral therapy for seasonal and pandemic influenza that we are actively developing with the US Centers for Disease Control. This antiviral therapy also has shown to have therapeutic benefits in the treatment of Ebola virus.

In the realm of neuroscience, we have efforts to target Alzheimer’s disease, chronic pain, and depression using nano particles that deliver micro RNA and signal interference RNA designed to up-regulate and down-regulate key proteins. The preclinical data from both in vitro and in vivo studies look extremely promising.

Furthermore, we are currently in developing of two hand-held devices for screening for infections related to prosthetic implants (such as joint replacement). They could be used in the operating room and clinics across the US. Our goal is for orthopedic surgeons to be able to measure specific infection markers at their fingertips to enable them to make safe and cost-effective medical management decisions based on an accurate and precise screening tool. One of the devices will be iPhone compatible, while the other we are developing as a stand-alone device that would be ideal for markets in developing countries.

Our hope is that our platform will extend to diagnosing infectious diseases, be used in the Intensive Care Unit for basic metabolic panel measurements and be extended to a host of other medical applications. We will likely begin FDA clinical trials for these devices by early 2016.  I am also working on developing a platform for detection of various disease processes using nanotechnology and breath as a medium for detecting specific breath-based biomarkers.

INBT: What sort of collaborations are you hoping to establish?

KC: I am hoping to use the extensive knowledge at INBT and at Hopkins to help further our development efforts. As an affiliated faculty, I feel honored to be part of such an impressive think tank of scientists and entrepreneurs. I believe nanotechnology is at the heart of the bench-to-bedside paradigm. It is one component of the growing medical revolution that is happening around the world. In addition, unlike any other industry or science, nano medicine advances are going to be interdisciplinary and collaborative. So teamwork, collaboration, and collective ideas are going to push ongoing advances and development.

INBT: What are the main research challenges you would like to address?

KC: At present, the main stumbling block will be pushing our technology through FDA clinical trials. The process is long, tedious, and expensive. In addition, preclinical data has to be sound. So refinement of the nano materials to find the ideal candidate to deliver the gene or drug will require creativity and repeated experimentation. In addition, when thinking about the ultimate goal of seeing these drugs being used in patients, large-scale production becomes an important component to address.  It has to be of consistent quality, safe, and easily reproducible in large quantities.  So these are things we need to think about from an industrial perspective when you are no longer in the academic realm.

INBT: Anything else people should know?

KC: I am looking forward to working with other INBT faculty.  We are always open to new ideas, and my research team would be more than willing to start new projects.  Likewise, we will also try and suggest areas that we think specific faculty would be suitable for project development.

Visit the Chakravarthy Research Group Website:

Recent Publications:

Jacob A, Chakravarthy K (2014-04-06 14:52:34 UTC) Engineering Magnetic Nanoparticles for Thermo-Ablation and Drug Delivery in Neurological Cancers. Cureus 6(4): e170. doi:10.7759/cureus.170

Jacob A, Chakravarthy K, Law M, et al. (2014-04-21 18:33:15 UTC) Neuroradiology, Anesthesia, Bioengineering, and Hardware Programming in the Clinical Applications of Deep Brain Stimulation. Cureus 6(4): e172. doi:10.7759/cureus.172

Upcoming Invited Talks:

Designing smart nano-systems for effective gene and drug delivery across the blood brain barrier.  12th Annual World Brain Mapping and Therapeutics Congress.  March 6-8, 2015, Los Angeles, USA

Selective abrogation of IL-12/IL-23 production provides novel therapeutic modality in combating lethal synergism of influenza and secondary pneumonia.  5th World Congress on Cell Science and Stem cell research.  March 23-25, 2015, Chicago, USA

Periodically Johns Hopkins Institute for NanoBioTechnology (INBT) features a brief profile on one of its affiliated faculty members. If you are an affiliated faculty member of INBT and would like to be featured, contact INBT’s science writer, Mary Spiro at If you wish to become an affiliated faculty member visit this link.





Poster presenters sought for Neuro X symposium

Johns Hopkins Institute for NanoBioTechnology (INBT) hosts its ninth annual symposium on May 1, 2015 in the Owens Auditorium on the Johns Hopkins medical campus. The theme for the speakers this year is Neuro X, where X stands for medicine, nanotechnology, engineering, science and more! Posters on any multidisciplinary theme are now being accepted. You do not have to be a member of an INBT affiliated laboratory to participate. Undergraduates, graduate students and postdoctoral fellows welcome. The event is free for Johns Hopkins associated persons. There is a fee for those outside of JHU/JHMI/JHH and is listed on the registration form.

Full details on poster guidelines and current information on the symposium can be found on the Neuro X website. To submit a poster or to simply register to attend the symposium, click here.

neuro-x-ad-flatThe symposium will begin at 8 a.m. with continental breakfast. Talks will begin at 9 a.m. and continue through 12:15 p.m. Speakers include: Alfredo Quiñones-Hinojosa, MD, FAANS, Professor of Neurological Surgery and Oncology Neuroscience and Cellular and Molecular Medicine; Jordan J. Green, PhD, Associate Professor of Biomedical Engineering, Ophthalmology, Neurosurgery, and Materials Science & Engineering; Ahmet Hoke MD, PhD, FRCPC, Professor, Neurology and Neuroscience; Patricia H. Janak, Professor, Department of Psychological and Brain Sciences/Department of Neuroscience in the Krieger School of Arts and Sciences; Piotr Walczak, MD, PhD, Associate Professor, Department of Radiology and Radiological Science; and Martin G. Pomper, MD, PhD, the William R. Brody Professor of Radiology and Radiological Science. This year’s symposium chairs are INBT director Peter Searson, Reynolds Professor, Materials Science and Engineering, and Dwight Bergles, Professor, the Solomon H. Snyder Department of Neuroscience, Department of Otolaryngology, Head & Neck Surgery.

The poster session will begin at 1:15 p.m. and conclude at 3:30 p.m. with poster prize presentations. Speaker talk titles, poster prizes and other details will be announced in the next few weeks. Don’t miss your chance to participate in one of Johns Hopkins largest, most popular and most well attended symposiums. Plan now to attend and present.

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




Winter professional development seminars slated

Johns Hopkins Institute for NanoBioTechnology (INBT) will present two professional development seminars this winter to keep you informed and help you on your career path. RSVP is required to attend.

Financial careers for scientists and engineers

Sheryl Zhou

Sheryl Zhou

Sheryl Zhou of Brown Advisory, an independently owned investment firm, will visit on January 26 at 3:30pm in the Mason Hall boardroom. She will discuss opportunities and career paths for PhD scientists in the financial and consultant fields.

Zhou is a member of the equity research team covering the health care sector. Prior to joining Brown Advisory, she covered the biotech/pharmaceutical sector at Adage Capital and Cayuga Fund during business school.

Zhou received her Ph.D. in Biomedical Sciences from Cornell Medical School and worked at Memorial Sloan Kettering Cancer Center for six years. She also received an MBA from the Johnson School at Cornell University.

Pathways to entrepreneurship

Jennifer Hammaker, Director of the Maryland Innovation Initiative at Maryland Technology Development Corporation (TEDCO) will join us on February 10, also at 3:30pm in the Mason Hall boardroom. She will
discuss opportunities in entrepreneurship and business formation.

Jennifer Hammaker

Jennifer Hammaker

Prior to joining TEDCO, Hammaker was Director of the Innovation Transfer Network, a first-of-its-kind Pennsylvania network of thirteen small colleges and universities focused on commercialization.

INBT presents these professional development seminars as a service and outreach to the Johns Hopkins Community. To attend any of INBT’s professional development seminars, please RSVP to Ashanti Edwards at

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


Drug-chemo combo destroys challenging breast cancer stem cells

Gregg Semenza

Gregg Semenza

Researchers affiliated with Johns Hopkins Physical Sciences-Oncology Center (PS-OC) have shown that combining chemotherapy with an agent that blocks a certain cancer survival protein holds the key to fighting one of the the toughest forms of breast cancer.

Only 20 percent of patients with what are known as “triple-negative” breast cancer cells respond to chemotherapy. PS-OC associate director and Johns Hopkins professor of  medicine Gregg Semenza demonstrated in a recent study that chemotherapy actually enhances triple-negative cancer stem cell survival by switching on proteins called hypoxia-inducible factors (HIF). But when combined with currently available and FDA-approved HIF-inhibiting drugs, such as digoxin, Semenza said, chemotherapy shrank tumors.

Mice with implanted triple-negative breast cancer stem cells were treated with a combination therapy comprised of the HIF-inhibiting drug plus the chemotherapeutic drug paclitaxel. That combo treatment decreased tumor size by 30 percent more than treatment with chemotherapy. Furthermore, Semenza’s study showed that combining digoxin with the a different chemotherapeutic agent called gemcitabine “brought tumor volumes to zero within three weeks and prevented the immediate relapse at the end of treatment that was seen in mice treated with gemcitabine alone,” a press release on the study stated. Clinical trials will be needed to verify these results.

Debangshu Samanta, Ph.D., a postdoctoral fellow in the Semenza lab, was the lead author on this research published online in the Proceedings of the National Academy of Sciences. Additional authors include Daniele Gilkes, Pallavi Chaturvedi and Lisha Xiang of the Johns Hopkins University School of Medicine.

Read the PNAS article here.

Visit the PS-OC website here.

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


Gerecht nets American Heart Association grant

Sharon Gerecht, associate professor in the Department of Chemical and Biomolecular Engineering and affiliated faculty member of Johns Hopkins Institute for NanoBioTechnology, has received the prestigious American Heart Association Established Investigator Award.

sharongerecht_cropThe AHA awarded only four such grants this year, funding designed to support mid-career of investigators who show unusual promise and accomplishments in the study of “cardiovascular or cerebrovascular science.”

Gerecht’s research focuses on engineering platforms, specifically hydrogels, that are designed to coax stem cells to develop into the building blocks of blood vessels. The hope is that these approaches could be used to help repair circulatory systems that have been damaged by heart disease, diabetes, and other illnesses.

Additionally, Gerecht leads a research project in the Johns Hopkins Physical Science-Oncology Center where she is studying the effects of low oxygen (hypoxia) on the tumor growth and blood vessel formation. The AHA funding will support her work on regulating hypoxia in hydrogels for vascular regeneration. The award is worth approximately $400,000 over five years.

Learn more about the Gerecht lab here.

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


Sciencescape rescues researchers from never-ending flow of published data

Screen Shot 2014-12-03 at 1.28.38 PMI like to listen to as much new music as I can. But I realized long ago that there would never be enough hours in the day or days in my lifetime to sift through all the new stuff to discover cool new tunes, even in the genres I preferred.

Scientists and engineers have similar problems staying current with research relevant to their disciplines. A report published in November 2012 by the International Association of Scientific, Technical and Medical Publishers estimated that 1.8 million papers are published in 28,000 academic journals every year. That’s a lot of data and a lot of discussion about that data. Another study published in 2007, reported that very little of this research is ever read by anyone. Only a wee bit of it is going to help you finish your dissertation, refine your protocol or provide the foundations to your next big breakthrough.

Thankfully some smart folks at have figured out a nifty way for you to sift through this mountain of virtual paper. Sciencescape pulls in data from available online journal databases, like PubMed, Google Scholar and many more going back to 1880. Using your chosen criteria, Sciencescape creates sort of a news feed of published research that may be important for you. You can use search criteria such as author, topic, journal name, and publication date. You can even keep track of research coming out of a specific lab or follow authors as you would follow people on Twitter.  Sciencescape uses Eigenfactor metrics, which pinpoints papers that are highly cited and by high impact journals, both good indicators that a paper is worth checking out. It helps you find the quality research. Sciencescape can even assist with finding papers on topics for your undergraduate journal club.

One especially cool feature of Sciencescape is the ability to set up a laboratory profile where the work of lab members can feed into one stream. That way you know what your colleagues at the next lab bench or down the hall are publishing. By breaking down these virtual walls between labs, departments and even universities, Sciencescape facilitates collaborations, which is something Johns Hopkins Institute for NanoBioTechnology has fostered since inception.

The Sciencescape user interface is attractive and easy to read, which entices even someone like me (who is not actively engaged in research) into exploring a topic. It did not take me very long before I had fallen down a rabbit hole of knowledge! You can save papers to a library or share them on social media like Facebook and Twitter, because of course your mom and your college buddies want to know you are keeping up with current research in nanobiotechnology!

Sciencescape was listed by The Scientist magazine as a Top Innovation for 2014, and it is evident as to why. Now if they could only come up with an Eigenfactor metric that would work for music so I could avoid listening to music I probably wouldn’t like. PS, this is not a paid advertisement for Sciencescape, I just thought it seemed really useful. I am now keeping track of several INBT faculty researchers on Sciencescape.

Watch a video on Sciencescape here.


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

Research Remix calls for posters

Johns Hopkins Digital Media Center (DMC) is inviting artists and researchers to collaborate on works of visual art that expand on the theme of the original science. The goal of the project is to make research more accessible and engaging to the public.

research-remix-draft-feature1To begin the collaboration process students, staff or faculty are asked to submit posters (presumably ones you don’t need anymore) to the DMC, located in the Mattin Center on the Homewood campus. The posters will be used as source material and to be reimagined and re-interpreted by a group of visual artists, including some artists from MICA. The posters and the ideas they present could be visualized as an illustration, painting, sculpture, computer animation or something else entirely.

Both researchers and artists are needed for this project, which begins now. During the visualization process, artists and researchers will meet to discuss the poster content and the resulting artist’s interpretation. The meet-and-greet will take place in February 2015. The project will culminate in April 2015 with a gallery exhibition at JHU.

Read more about this project at this link. If you are interested in participating in the DMC’s Research Remix send an email to and put REMIX in the subject line.