Hand-held device will quickly ID bacteria

Tza-Huei (Jeff)Wang, a mechanical engineering professor affiliated with Johns Hopkins Institute for NanoBioTechnology, received a $6 million grant from the National Institutes of Health to develop a hand-held device that will quickly indentify bacteria.

Droplet-chip-photo-Wang-Lab-crop-1020x1024

This illustration depicts a microfluidic chip for bacterial detection and drug testing in picoliter-sized droplets. Graphic by Jeff Wang Lab/Johns Hopkins University.

“We need to be faster and more precise in the way we diagnose and treat people with bacterial infections,” said Wang, who is leading the team that will build the new microfluidic testing devices. “Instead of waiting three days to figure out what the infection is and what’s the best drug to treat it, we believe our technology will deliver both answers within just three hours.”

Wang explained that delays in bacterial identification lead physicians to rely on broad spectrum antibiotics, which in turn can lead to drug resistance. Discovering quickly which bug is causing the infection, Wang said “should lead to more effective treatment and a lower risk of promoting antibiotic resistance.”

Wang’s award, which will be distributed over five years toward the development of this life-saving microfluidic device, came from National Institute of Allergy and Infectious Diseases (NIAID).

Read more here.

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

The challenge of accurately measuring drug permeability

In our seventh NanoBio Lab, Erin Gallagher, a predoctoral candidate from the lab of professor Peter Searson, demonstrated the use of a cell permeability assay as a means of modeling drug diffusion through the blood brain barrier (BBB) endothelium. Assays such as this one enable us to better understand the cellular processes that govern what drug molecules are able to cross the BBB and the role of efflux pumps and transporters. Development of more accurate in vitro models is a highly valuable avenue of research, as it will allow for rational drug design to more effectively treat diseases such as Alzheimer’s, Parkinson’s and mood disorders with potentially fewer side effects.

The blood brain barrier (BBB) presents a challenge for delivery of drug molecules to the central nervous system, as many of the mechanisms it employs were evolved specifically to prevent introduction of dangerous substances into the central nervous system. Understanding the mechanisms by which various substances are able to cross the BBB will allow for more rational design of future generations of drug molecules and carrier systems.

The blood brain barrier (BBB) presents a challenge for delivery of drug molecules to the central nervous system, as many of the mechanisms it employs were evolved specifically to prevent introduction of dangerous substances into the central nervous system. Understanding the mechanisms by which various substances are able to cross the BBB will allow for more rational design of future generations of drug molecules and carrier systems.

For the assay, canine kidney cells (MDCK II) were seeded on transwells in a 24 well plate, 24 hours prior to the assay to allow the cells to form a confluent endothelial layer with functional tight junctions. When cells have formed a confluent endothelial layer, ion movement must occur through the cells themselves instead of through the much higher resistivity tight junctions. As a result, the overall resistivity measured is higher than for non-confluent cells, for which ions are able to simply diffuse through the transwell. Therefore, assessment of the integrity of the endothelial layer was done to measure the conductivity through the layer of cells.

Following assessment of the endothelial layer integrity, we ran a permeability assay for the fluorescent molecule Lucifer Yellow (LY) to determine its apparent permeability as a model for drugs diffusing across the BBB. Utilizing a standard concentration curve of LY fluorescence, the amount of LY that diffused through the layer was determined at specific time points to imply apparent permeability. For more typical non-fluorescent drug molecules, high performance liquid chromatography (HPLC) can be used to measure the amount of drug having diffused.

As a tool, assays modeling the blood brain barrier are indispensible to the pharmaceutical industry, but finding a model system that effectively reproduces in vivo conditions for less expensive, high throughput in vitro testing is a challenge. Permeability models, such as the one used in this lab, also allow development of novel strategies for moving drugs across the BBB. These strategies include molecular engineering of drug molecules to take advantage of cellular active transport mechanisms or peptide engineering that facilitates vesicle transport across the endothelium.

David Wilson is a first year PhD student in biomedical engineering working in the drug delivery laboratory of associate professor Jordan Green in biomedical engineering.

Image Citation:  Wong, A. D., Ye, M., Levy, A. F., Rothstein, J. D., Bergles, D. E., & Searson, P. C. (2013). The blood-brain barrier: an engineering perspective. Frontiers in Neuroengineering, 6(August), 1–22. doi:10.3389/fneng.2013.00007

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

Thoughts on stereotyping of Latina women in science

Angela Jimenez

Angela Jimenez

Recently an article in the Washington Post entitled, “Black and Latina women scientists sometimes mistaken for janitors,” was brought to my attention. The Nano-Bio blog editor and INBT science writer, Mary Spiro, asked me if I would be willing to write a response to it. After considering this topic and my experience in the States, I cannot say that I have felt stereotyped due to being a female Hispanic scientist.

Although stereotyping is a more profound issue, it is not completely unreasonable. Let me explained myself: I recently defended my PhD work at Johns Hopkins University and in the five and a half years that I have spent here, most of the janitors are blacks including a few Hispanics. When I would walk to lab, I could hear construction guys talking in Spanish all the time. Unfortunately, this stereotype is sometimes our current reality. This could be partly explained from the fact that some of us come from developing countries, and it is difficult when we come to the States to be up to speed with everyone else who has been born and raised here. This gap could be due to a variety of factors, such as the lack of education, the cultural differences, the language barrier, and even the influence of our family.

One of the reasons that I have not felt particularly stereotyped is probably because when I moved to the States 13 years ago, I came to New York City, which is known as the melting pot of this country. I went to City College of New York and out of a class of 30, there was only one person originally from the States. Everyone else was from somewhere around the world.

After arriving to the US, I was aware that I was coming from a developing country, and that I needed to work hard to succeed, which I would define as getting educated. When I decided to come here, I moved without my family and without knowing any English and I feel that the most important thing that made me succeed was the great desire and determination to learn and get educated. This determination probably made me so focus on achieving my goals that I never really thought about being stereotyped or discriminated even when this could had been the case.

Looking back, I can only say that yes, I worked really hard, but I have been extremely fortunate to be able to earn a PhD from one of the leading Universities. Now, do I think it is fair that women, in particular Blacks and Hispanics, are stereotyped or even discriminated? Of course not, but the issue here is greater than this. Stereotyping and discrimination depend on several variables. For instance, geography, demographics, education, and income all play a role.

I have Hispanic Engineer friends who work in different industries in non-traditional roles, and I have observed that the ones who work in New York City are less likely to be stereotyped or discriminated than the ones elsewhere. Do I think that as women we should support each other and create societies that inspire and help us navigate the system? Of course yes! Motivating and helping women pursue a career in the field of science will help increase the percentage of women in these challenging positions. Over time, this will lead to a greater representation of the number of blacks and Latina women scientists, and this current stereotype and discrimination will eventually vanish.

About the author: Angela Jimenez recently completed her PhD in Chemical and Biomolecular engineering in the laboratory of Denis Wirtz, associate director of INBT and Vice Provost for Research at Johns Hopkins University.

Top poster presenters awarded Nikon cameras at Neuro X symposium.

More than 300 people attended the Neuro X symposium hosted May 1 by Johns Hopkins Institute for NanoBioTechnology at the Owens Auditorium on the medical campus. The morning featured six faculty experts from several disciplines (see pdf of agenda here). In the afternoon, nearly 70 posters were on display and three presenters earned top honors for their work.  Posters were judged on research value, quality of content and overall graphic presentation. Prizes included three different Nikon Coolpix cameras, provided by Nikon.

Maria Barbano

1at prize winner Maria Barbano with INBT director Peter Searson

First prize went to Maria Flavia Barbano, a senior research specialist in the Department of Psychological and Brain Sciences, for her poster Differential effects of photoactivating GABAergic lateral hypothalamic neurons projecting to ventral tegmental area in feeding and reward.

Second prize was awarded to Ran Lin (not pictured), a predoctoral candidate in the Department of Chemical and Biomolecular Engineering, for her poster A Dual Peptide Conjugation Strategy for Improved Cellular Uptake and Mitochondria.

Third prize was presented to Jennifer Dailey, predoctoral candidate in the Department of Material Science and Engineering, for her poster Optoelectronic Signaling for detecting Methicillin-resistant Staphylococcus Aureus (MRSA) and Related Pathogens by Multidentate Antigen-Nanoparticle Agglomeration.

Jennifer Dailey

3rd prize winner Jennifer Dailey

INBT would like to thank our judges who came from the university and from industry. They included Chao Wang, assistant professor in chemical and biomolecular engineering, Peter Searson, INBT director and professor of materials science and engineering, Esther Kieserman of Nikon, and assistant professor Seulki Lee and professor Robert Ivkov both from the Johns Hopkins School of Medicine.

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

Chien’s magnetism work recognized with prestigious award

Chia-Ling Chien

Chia-Ling Chien

Professor Chia-Ling Chien, a condensed matter physicist at Johns Hopkins University and long-time affiliated faculty member of INBT, will receive the prestigious 2015 IUPAP Magnetism Award and Néel Medal from the Commission on Magnetism within the International Union of Pure and Applied Physics. Chien directs the Nanostructured Materials Lab in the Department of Physics and Astronomy at the Krieger School of Arts and Sciences.

The award, which will be presented this summer,  recognizes Chien’s pioneering discoveries in magnetic materials and nanostructures. The IUPAP Magnetism Award and Néel Medal are awarded every three years to a scientist who has made extraordinary contributions to the field of magnetism. The award is the highest honor bestowed by the IUPAP Commission on Magnetism.

Congratulations to Dr. Chien.

Read more about Dr. Chien’s award and research in this story on the JHU Hub.

 

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 http://inbt.jhu.edu/news/symposium/

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

 

 

 

Symposium speakers 2015: Alfredo Quiñones-Hinojosa

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 Alfredo Quiñones-Hinojosa, MD

Alfredo Quiñones-Hinojosa, MD

Alfredo Quiñones-Hinojosa, MD

Alfredo Quiñones-Hinojosa is an internationally renowned neurosurgeon and neuroscientist who leads cutting edge research to cure brain cancer at Johns Hopkins Hospital. He directs the Brain Tumor Surgery Program at Bayview Medical Center, the Pituitary Surgery Program at Johns Hopkins Hospital, and the Brain Tumor Stem Cell Laboratory at the Johns Hopkins School of Medicine. Named as one of the 100 most influential Hispanics in 2008, he was also selected by Popular Science magazine as one of their 6th Annual Brilliant Ten in their search for young researchers influencing the course of science. Dr. Quiñones has published over 260 peer-reviewed articles and over 40 book chapters and has edited two books on stem cells.  He is the lead editor for the 6th edition of Schmidek and Sweet’s Operative Neurosurgical Techniques, the world’s preeminent encyclopedia of neurosurgery, as well as an upcoming Video-Atlas of Neurosurgery: Tumors and Contemporary Skull Base Surgery.

Dr. Quiñones conducts numerous research efforts on elucidating the role of stem cells in the origin of brain tumors and the potential role stem cells can play in fighting brain cancer and regaining neurological function.  He has received R01 funding from the National Institutes of Health for his work with stem cells and cancer. His awards also include grants from the Howard Hughes Medical Institute Physician-Scientist Early Career Award, the Robert Wood Johnson Foundation, and the Maryland Stem Cell Foundation.  He has been invited to give more than 250 lectures nationally and internationally, including visiting professorships at several universities. An active science communicator, he has appeared in print and broadcast media, including NOVA, CNN, CBS News, NBC’s The Today Show, and National Public Radio. In 2014, he was the recipient of Voices Against Brain Cancer’s Neurosurgeon of the Year Award for his patient care and research strides to find a cure for brain cancer. He has also published an autobiography, “Becoming Dr. Q”, about his journey from migrant farm worker to brain surgeon, in both English and Spanish.

Additional speakers will be profiled in the next few weeks. To register your poster and for more details visit http://inbt.jhu.edu/news/ symposium/

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

 

Symposium speakers 2015: Martin Pomper

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 Martin G. Pomper, MD, PhD.

Martin Pomper, MD, PhD

Martin Pomper, MD, PhD

Martin Pomper is the William R. Brody Professor of Radiology at the Johns Hopkins School of Medicine, with a joint appointment in Chemical and Biomolecular Engineering at the Whiting School of Engineering. He received his undergraduate, graduate (organic chemistry) and medical degrees from the University of Illinois at Urbana-Champaign. His postgraduate medical training was at Johns Hopkins and included an internship (Osler Medical Service), residencies (diagnostic radiology and nuclear medicine) and fellowship (neuroradiology). He is board-certified in diagnostic radiology and nuclear medicine. He has been on the Radiology faculty at Johns Hopkins since 1996. He is currently the director of the Johns Hopkins Small Animal Imaging Resource and associate director of the In Vivo Cellular and Molecular Imaging Center, both funded by the National Cancer Institute to support molecular imaging research.

Dr. Pomper is director of the Johns Hopkins Center for Translational Molecular Imaging. He is co-director of the Johns Hopkins Center of Cancer Nanotechnology Excellence and the Positron Emission Tomography Center. His interests are in the development of new radiopharmaceuticals, optical probes and techniques for molecular imaging of cancer and central nervous system disease. His research group consists of chemists, physicists, molecular biologists and clinicians working together toward clinical molecular imaging. He is Editor-in-Chief of Molecular Imaging and a past President of the Society of Nuclear Medicine’s Molecular Imaging Center of Excellence. He has numerous patents related to medical imaging, many of which have been licensed, as well as several imaging agents in clinical trials.

Additional speakers will be profiled in the next few weeks. To register your poster and for more details visit http://inbt.jhu.edu/news/symposium/

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

Symposium speakers 2015: Patricia Janak

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 Patricia Janak, PhD.

Patricia Janak, PhD

Patricia Janak, PhD

Patricia Janak is a Bloomberg Distinguished Professor, with joint appointments in the Department of Psychological and Brain Sciences at the Krieger School of Arts and Sciences and at the Department of Neuroscience at the Johns Hopkins School of Medicine. She is known for her research on behavioral and neurobiological mechanisms of associative learning to better understand how stimuli associated with drugs and alcohol can cause addicts to relapse. Dr. Janak is interested in neural mechanisms underlying reward learning, for both natural and drug rewards. She earned her bachelor’s degree in psychology and biology from Rutgers University and her PhD in biopsychology from the University of California, Berkeley.

Dr. Janak conducted postdoctoral research at the Wake Forest School of Medicine and the National Institute on Drug Abuse, National Institutes of Health. From 1999 to 2014, Dr. Janak was faculty at the University of California, San Francisco where she was the Howard J. Weinberger, MD Endowed Chair in Addiction Research at the University of California, San Francisco, where she researched potential treatments for addiction. She joined the Hopkins faculty in 2014 as a Bloomberg Distinguished Professor. She serves on numerous advisory boards and committees, including serving as an NIH study section chair and as an associate editor for Science Advance. In addition, she is involved with the newly created Science of Learning Institute Signature Initiative, an interdisciplinary effort dedicated to improving how people think and learn.

Additional speakers will be profiled in the next few weeks. To register your poster and for more details visit http://inbt.jhu.edu/news/symposium/

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

Nano-bio lab course: microvasculature scaffolds

Editor’s note: Over the next several days, we will share the student impressions of some of the techniques learned in INBT’s nano-bio laboratory course (670.621). These reports demonstrate the wide variety of techniques students trained at the Johns Hopkins Institute for NanoBioTechnology are expected to understand. Each technique is taught in a different affiliated faculty lab. More lab techniques to come.

Tiny scaffolds build microvessels

In the Sharon Gerecht lab led by her PhD candidate Sebastian Barreto, we learned about the protocol they use for constructing microvasculature using a 250-micron diameter fibrin fiber scaffold. The scaffold has endothelial colony forming cells seeded on the surface that rapidly proliferate and excrete ESM to form a cell-based structure around the fibrin fiber scaffold.

Lab6 Figure DRW

A) Confocal microscopy image of collagen IV from endothelial colony forming cells seeded on fibrin fibers of various diameters. (B) Scatter plot of angle of collagen IV deposition showing significance between the 445 um fiber and 105-370 um fibers. The significance of the finding is that the endothelial cells are unable to sense the curvature of the fiber above 445 um.

The addition of plasmin to the media allows the fibrin scaffold to be rapidly degraded leaving the cell construct in the shape of a micro-vessel, after which media can be perfused through the vessel with a pulsatile pump to simulate heart powered blood flow and stimulate the cells within the construct. The method of creating the cell construct also allows for the seeding of perivascular cells on the surface of the endothelial cells to study the interaction between the two cell types.

Confocal microscopy following fixing and staining of the cell construct allows the orientation of the ECM and cell proliferation to be analyzed. As a tool for studying endothelial blood vessel formation this platform technology is very interesting. Of particular interest is the fact that above a certain diameter of the fibrin fiber the endothelial cells do not rearrange, indicating that they have a mechanism for sensing the effective radius of curvature of the vessel.

Reference: Barreto-Ortiz SF, Zhang S, Davenport M, Fradkin J, Ginn B, et al. (2013) A Novel In Vitro Model for Microvasculature Reveals Regulation of Circumferential ECM Organization by Curvature. PLoS ONE 8(11): e81061. doi:10.1371/journal.pone.0081061

About the author: David Wilson is a first year PhD student in biomedical engineering working in the drug delivery laboratory of Jordan Green.

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