Lab-on-a-chip helps understand cardiovascular disease

Cardiovascular disease is the leading cause of death in the United States accounts for over 600,000 mortalities and $400 billion dollars in health related costs annually. If we can study vascular behavior in an in vivo mimicking environment, we can better understand how the roadblocks of chemical inflammation, elevated blood pressure, plaque formation and blood vessel narrowing contribute to cardiovascular disease.

Endothelial colony forming cells with shear stress.

Endothelial colony forming cells with shear stress.

The circulatory system contains a dense network of blood vessels, which are the highways that sustain underlying tissue by mediating the transfer of nutrients and removal of waste. These highways are lined with mechanosensing endothelial cells (ECs) that direct the travel of sustenance contained within the blood by acting as selective barriers.

One hallmark behavior of ECs is their ability to align and elongate in response to blood flow generated from heart contraction. By recapitulating this scenario in the lab using microfluidic (lab-on-a-chip) systems, ECs can be cultured in dynamic environments that circumvent the limitations of traditional in vitro culture platforms.

About the author: Quinton Smith is a third year graduate student in the Department of Chemical and Biomolecular Engineering, studying the effects of physio-chemical cues governing stem cell behavior and maturation under the mentorship of Sharon Gerecht, associate professor. 

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

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: http://ins.sjtu.edu.cn/people/jakob/)

Figure 1: Membrane Active Peptide Schematic (Source: http://ins.sjtu.edu.cn/people/jakob/)

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, mspiro@jhu.edu 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:
(1) http://www.cdc.gov/drugresistance/national-strategy/
(2) http://www.niaid.nih.gov/topics/antimicrobialResistance/understanding/Pages/quickFacts.aspx

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.

microfluidicdevice

Figure 1: A picture of a general microfluidic device. Source: http://blogs.nature.com/spoonful/2012/02/chip-promises-better-diagnosis-for-common-blood-disorder.html)

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, mspiro@jhu.edu 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: www.nanoaxisllc.com

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 mspiro@jhu.edu. If you wish to become an affiliated faculty member visit this link. http://inbt.jhu.edu/apps/faculty/join/

 

 

 

 

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, mspiro@jhu.edu 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, mspiro@jhu.edu 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 Sciencescape.org 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, mspiro@jhu.edu or 410-516-4802.

Podcast: Artificial blood vessel visualizes cancer cell journey

Researchers from Johns Hopkins Institute for NanoBioTechnology are visualizing many of the steps involved in how cancer cells break free from tumors and travel through the blood stream, potentially on their way to distant organs.  Using an artificial blood vessel developed in the laboratory of Peter Searson, INBT director and professor of materials science and engineering, scientists are looking more closely into the complex journey of the cancer cell.

Figure 1. 3D projection of a confocal z-stack shows human umbilical vein endothelial cells (HUVECs) forming a functional vessel immunofluorescently stained for PECAM-1 (green) and nuclei (blue).

Figure 1. 3D projection of a confocal z-stack shows human umbilical vein endothelial cells (HUVECs) forming a functional vessel immunofluorescently stained for PECAM-1 (green) and nuclei (blue). (Wong/Searson Lab)

INBT’s science writer, Mary Spiro, interviewed device developer Andrew Wong, a doctoral student Searson’s  lab, for the NanoByte Podcast. Wong is an INBT training grant student. Listen to NANOBYTE #101 at this link.

Wong describes the transparent device, which is made up of a cylindrical channel lined with human endothelial cells and housed within a gel made of collagen, the body’s structural protein that supports living tissues. A small clump of metastatic breast cancer cells is seeded in the gel near the vessel while a nutrient rich fluid was pumped through the channel to simulate blood flow. By adding fluorescent tags the breast cancer cells, the researchers were able to track the cells’ paths over multiple days under a microscope.

VIDEO: Watch how a cancer cell approaches the artificial blood vessel, balls up and then forces its way through the endothelial cells and into the streaming fluids within the channel of the device. (Video by Searson Lab)

The lab-made device allows researchers to visualize how “a single cancer cell degrades the matrix and creates a tunnel that allows it to travel to the vessel wall,” says Wong. “The cell then balls up, and after a few days, exerts a force that disrupts the endothelial cells. It is then swept away by the flow. “

Wong said his next goal will be to use the artificial blood vessel to investigate different cancer treatment strategies, such as chemotherapeutic drugs, to find ways to improve the targeting of drug-resistant tumors.

Results of their experiments with this device were published in the journal Cancer Research in September.

Andrew Wong (left) and Peter Searson. (Photo by Will Kirk/Homewood Photography)

Andrew Wong (left) and Peter Searson. (Photo by Will Kirk/Homewood Photography)

Check out this gallery of images from the Searson Lab. The captions are as follows:
Figure 1. 3D projection of a confocal z-stack shows human umbilical vein endothelial cells (HUVECs) forming a functional vessel immunofluorescently stained for PECAM-1 (green) and nuclei (blue).
Figure 2. 3D projection of a confocal z-stack shows human umbilical vein endothelial cells (HUVECs) forming a vessel with dual-labeled MDA-MB-231 breast cancer cells on the periphery.
Figure 3. Phase-contrast and fluorescence overlays depicting a functional vessel comprised of human umbilical vein endothelial cells (HUVECs) with dual-labeled MDA-MB-231 breast cancer cells on the periphery (green in the nucleus, red in the cytoplasm).

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

 

Don’t believe everything (peer-reviewed) you read on the web

Recently, my attention was drawn to an article the same way I find many articles: through Facebook. Several of my many science-minded friends referenced a recent article from sciencemag.org entitled “Who’s Afraid of Peer Review?”, where a spoof paper with clearly bad controls was submitted to 304 open access journals and was accepted by 157. After reading a variety of comments with tones ranging from outrage to, “damn, I need to start writing some fake papers,” there was no way I wasn’t going to check out the article.

peer review image

Image used with permission from http://strange-matter.net/screen_res/nz060.jpg

Basically, some writers from Science generated a fake paper the claimed a chemical extracted from a lichen had shown anticancer properties. While the article claimed that there was a strong dose-dependent effect of the drug on the cancer cells, the effect barely varied over 5 orders of magnitude. The paper claimed that the chemical was dissolved in large amounts of ethanol before being added to cells, but the control cells were given no ethanol, meaning that likely what was killing the cells was not in fact the chemical, but the ethanol itself. Testing controls with the same solvent as the other conditions is standard, especially when large amounts of the solvent itself can have toxic effects. The spoof paper also went on to make large claims about how the molecule tested has potential as an anticancer drug.

It would seem likely, given the inherent flaws in the article, that the academics reviewing this paper would immediately raise a red flag about its content. However, the majority of the journals accepted the paper, including 45% of the journals in the Directory of Open Access Journals (DOAJ), which is meant to identify the credible open access journals. Many of the journals that offered the authors any feedback ignored the glaring scientific mistakes and simply made suggestions for changes in formatting.

As a grad student, I read peer-reviewed papers nearly every day. And while I’ve always known that I should be critical of everything I read, I was still shocked that this spoof article with such glaringly bad science was accepted by so many publishers. While I’m not as tempted to submit my own fake articles as some of my Facebook friends, this sting operation performed by the writers at Science is making me much more skeptical of papers I find on the web.

Amanda Levy is a doctoral student in the materials science and engineering laboratory of Peter Searson, director of INBT.

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