Making therapeutic proteins last longer

Happy TRAILs to you: PEGylation of proteins through complementary interactions between a His-tag and a Ni2+ complex of nitrilotriacetic acid (NTA, see picture), a well-established practice in protein research, was used to improve the half-life of therapeutic proteins in the blood following systemic administration in vivo. Animal models show that this site-specific modification improves the efficacy of modified TRAIL proteins.

Happy TRAILs to you: PEGylation of proteins through complementary interactions between a His-tag and a Ni2+ complex of nitrilotriacetic acid (NTA, see picture), a well-established practice in protein research, was used to improve the half-life of therapeutic proteins in the blood following systemic administration in vivo. Animal models show that this site-specific modification improves the efficacy of modified TRAIL proteins.

Proteins are responsible for pretty much everything in the human body. When there is a problem with the proteins, it usually leads to disease.

Protein therapy shows enormous potential for treating disease. But sometimes the proteins in a therapeutic treatment break down or are metabolized before they ever reach their target destination.

In a recent paper published in Angewandte Chemie, researchers from the laboratories of Martin Pomper (radiology oncology) and Seulki Lee (radiology, Center for Nanomedicine) at the Johns Hopkins School of Medicine and developed a simple method to validate protein drugs in animal models, said Lee. An illustration related to the paper appeared on the cover of the journal.

“We show that we can extend the half-life, that is, the amount of time the drug stays in the blood, while maintaining the activity of the model protein drug, TRAIL,” said one of the lead authors Maggie Swierczewska. “This has great implications for drug screening and validation methods, especially for the growing protein drug market.”

According to the paper, by attaching a molecule of  polyethylene glycol (PEG) to certain sites on the TRAIL protein drugs through an already well known method, the half-life of the drug could be extended without affecting its beneficial activity.

Authors on this paper include Tae Hyung Kim, Magdalena Swierczewska, Yumin Oh, AeRyon Kim, Dong Gyu Jo, Jae Hyung Park,  Youngro Byun, Scheherazade Sadegh-Nasseri, Martin G. Pomper, Kang Choon Lee, Seulki Lee. Author affiliations include the departments of Radiology and Pathology at the Johns Hopkins School of Medicine, the Johns Hopkins Center of Cancer Nanotechnology Excellence, the Johns Hopkins Institute for NanoBioTechnology, Center for Nanomedicine and collaborators at Sungkyunkwan University and Seoul National University, both in Korea.

Reference: Kim, T. H., Swierczewska, M., Oh, Y., Kim, A., Jo, D. G., Park, J. H., Byun, Y., Sadegh-Nasseri, S., Pomper, M. G., Lee, K. C. and Lee, S. (2013), Mix to Validate: A Facile, Reversible PEGylation for Fast Screening of Potential Therapeutic Proteins In Vivo. Angew. Chem. Int. Ed.. Vol. 52, Issue 27, pages 6880-6884, doi: 10.1002/anie.201302181

Lindau: where the Nobel Laureates gather

If you want to rub elbows with Nobel Laureates, the place to be this week is Lindau, Germany. Three of the four Johns Hopkins University graduate students attending the 63rd Annual Lindau Nobel Laureate meeting, which is dedicated to chemistry thie year, work in Institute for NanoBioTechnology affiliated laboratories. The meeting runs from June 30 to July 5 and will host more than 550 young researchers from 78 countries.

Allison Chambliss, a doctoral student in chemical and biomolecular engineering from the laboratory of Denis Wirtz; Sravanti Kusuman, a doctoral student in biomedical engineering from the laboratory of Sharon Gerecht; and Allix Sanders, a graduate student in chemistry from the laboratory of J.D. Tovar,  were chosen to attend along with 71 other top U.S. graduate student researchers. This year’s group is sponsored by the U.S. Department of Energy, Mars, Incorporated, the National Science Foundation, and the Oak Ridge Associated Universities (ORAU).

Before she left, Allison said she was excited about the opportunity to interact with successful and well known researchers, which is harder to do at big conferences. Essentially, she and the others will be chatting with the “rockstars” of science. Allison was able to attend despite also having a summer internship with Novozyme in Raleigh, NC, where she is working in their R&D department on biofuels.

“I liked hearing about how it was so interactive and that there will be people from all over the world. And then the fact that there will be Nobel Laureates, you don’t get the chance to meet someone like that every day, “ Allison said. She also sees this as an opportunity to network in case she wants to do a postdoctoral fellowship in another country. “I will be meeting people from labs all over the place and also people in both academia and industry.”

Allison’s current research in the Wirtz lab involves using high-throughput cell phenotyping to look at the physical characteristic of cells on a single cell basis and how physical attributes can impact a cell genetically. Allison did her undergraduate work at Virginia Tech.

Sravanti’s did her undergraduate work at MIT. Her research in the Gerecht lab involves using pluripotent stem cells and a specially engineered synthetic matrix to grow a micro-vasculature (tiny blood vessels).

“These are the seminal leaders in their field, and in many cases, they are the ones that created their fields, so I just think it will be great to learn the science from their standpoint,” Sravanti said. “You know, like what obstacles did they have to overcome to prove their point, since all their findings would be really novel.”

She is also interested in learning what inspires and keeps these leading figures going. “This is also a more intimate setting,” Sravanti added. “There are lectures in the morning but in the afternoon there are smaller roundtable discussions where you can get more intimate with whichever Nobel Laureate you choose to talk to.

Allix Sanders is working on a project in the Tovar lab that incorporates large, unique chromophores comprised of extended pi-conjugated networks into peptide chains. Following self-assembly, the photophysical characterizations of the supramolecular polymers will be investigated with the future goal of creating useful electronic materials. Allix did her undergraduate studies at Lebanon Valley College.

The fourth Johns Hopkins University student is Joseph Schonhoft, a doctoral student in the biophysics department, which is part of the Krieger School of Arts and Sciences. He works in the laboratory of James Stivers at the School of Medicine. His research involves facillitated diffusion mechanisms of DNA repair enzymes.

According to information from ORAU, Nobel Laureates have annually convened in Lindau since 1951 to have open and informal meetings with students and young researchers from around the world. Laureates and students exchange ideas, discuss projects and build international networks throughout the week. All attendees must pass through a competitive application and selection process managed by the Council for the Lindau Nobel Laureate Meetings. Throughout the week, the 35 participating Laureates will lecture in the mornings on the topic of their choice related to chemistry and participate in smaller question and answer sessions in the afternoons. Students will also interact with the Laureates and other international students during the week for more informal discussions. This year, with the addition of science master classes, a select few researchers will have the opportunity to present their research to a Nobel Laureate and a small group of their peers.

For more information regarding the 63rd Lindau Meeting of Nobel Laureates and Students, visit the ORAU–Lindau website. The ORAU-Lindau website and all logistical arrangements for the participants are being administered by the Oak Ridge Institute for Science and Education, a DOE institute managed by ORAU.

Lab coats are summer gear for high school researchers

You don’t think of a lab coat as summer wear for teens, but we don’t quite feel like it’s summer around here until our research interns have arrived. Early in June, INBT’s undergraduate nano-bio researchers arrived. This week our high schoolers in the Summer Academic Research Experience (SARE) scholars got started.

SARE pairs specially selected teens with university mentors who guide them through a mini research project. At the end of their time here, they hold a small poster session. The students gain valuable work skills, learn about scientific careers, get tutoring help, practice their writing, gather data for their projects and earn some cash for the future. Students in the program are recruited from the Boys Hope Girls Home of Baltimore program, The SEED School of Maryland and The Crossroads School, all of which assist in differing ways with in the education, housing, tutoring  and counseling of promising young people from disadvantaged circumstances.

The SARE program was launched in 2009 by Doug Robinson, professor in the cell biology department at the School of Medicine, and is funded jointly by the medical school and Johns Hopkins Institute for NanoBioTechnology.

This year’s SARE scholars include: Diana Bobb is being mentored by Makoto Tanigawa in the Takanari Inoue Lab in the Department of Cell Biology; Kaleel Byrd is being mentored by Ryan Vierling in the Caren Meyers Lab in the Department of Pharmacology; Milan Dower is being mentored by Tom Lampert in the Peter Devreotes Lab in the Department of Cell Biology; Jewel Herndon is being mentored by Herschel Wade in his lab in the Department of Biophysics; De’Sean Markley is being mentored by Hoku West-Foyle in the Douglas Robinson Lab in the Department of Cell Biology

2013 summer nano-bio research interns get to work

Johns Hopkins Institute for NanoBioTechnology welcomes its summer 2013 research interns. Students arrived from universities from across the nation to conduct 10 weeks of research in INBT sponsored laboratories. Interns are supported by the National Science Foundation Research Experience for Undergraduates  program through INBT and receive housing and a stipend during their tenure at Hopkins. At the end of their research project, students will present posters describing their work with other Hopkins students in a university-wide poster session.

This year’s students include:

Shantel Angstadt is from Elizabethtown College. She is working in the cell biology laboratory of Doug Robinson at the Johns Hopkins School of Medicine.

Hamsa Gowda is from UMBC. She is working in the materials science and engineering laboratory of Peter Searson at the Whiting School of Engineering.

Toni-Rose Guiriba is currently studying at Baltimore County Community College. She is working in the radiation oncology laboratory of Robert Ivkov at the School of Medicine.

Sarah Hansen is from the University of Virginia and is working with Jordan Green in his biomedical engineering laboratory at the School of Medicine.

Devante Horne studies at Clemson University and is conducting research with Honggang Cui in his chemical and biomolecular engineering laboratory at the Whiting School of Engineering.

Cameron Nemeth is from the University of Washington and is working in the materials science and engineering laboratory of Hai-Quan Mao at the Whiting School of Engineering.

Victoria Patino studies at Carnegie Mellon University and also works in the materials science and engineering laboratory of Hai-Quan Mao.

Camilo Ruiz studies at MIT and works with Deniz Wirtz in his chemical and biomolecular engineering laboratory at the Whiting School of Engineering.

Marc Thompson studies at North Carolina A & T State University and is conducting research in the biomedical engineering laboratory of Warren Grayson at the School of Medicine.

Breanna Turner is from Fort Valley State University and works in the materials science and engineering laboratory of Margarita Herrera-Alonso at the Whiting School of Engineering.

Jordan “Jo” Villa is from The College of William and Mary and conducts research in the chemistry laboratory of J.D. Tovar in the Krieger School of Arts and Sciences.





Fraley nets $500K Burroughs Wellcome Fund award for microfluidics work

Stephanie Fraley (Photo: Homewood Photography)

Stephanie Fraley (Photo: Homewood Photography)

A Johns Hopkins research fellow who is developing novel approaches to quickly identify bacterial DNA and human microRNA has won the prestigious $500,000 Burroughs Wellcome Fund (BWF) Career Award at the Scientific Interfaces. The prize, distributed over the next five years, helps transition newly minted PhDs from postdoctoral work into their first faculty positions.

Stephanie Fraley is a postdoctoral fellow working with Samuel Yang, MD, in Emergency Medicine/Infectious Disease at the Johns Hopkins School of Medicine and Jeff Wang, PhD, in Biomedical Engineering with appointments in the Whiting School of Engineering and the medical school. The goal of her work is to develop engineering technologies that can diagnose and guide treatment of sepsis, a leading cause of death worldwide, while simultaneously leading to improved understanding of how human cells and bacterial cells interact.

“Sepsis is an out of control immune response to infection,” Fraley said. “We are developing tools that are single molecule sensitive and can rapidly sort and detect bacterial and host response markers associated with sepsis. However, our devices are universal in that they can be applied to many other diseases.”

Fraley is using lab-on-chip technology, also known as microfluidics, to overcome the challenges of identifying the specific genetic material of bacteria and immune cells. Her technology aims to sort the genetic material down to the level of individual sequences so that each can be quantified with single molecule sensitivity.

“Bacterial DNA is on everything and contamination is everywhere, so trying to find the ones associated with sepsis is like the proverbial search for the needle in the haystack,” Fraley said. “With microfluidics, we can separate out all the bacterial DNA, so instead of a needle in a haystack, we have just the needles.”

Another advantage to Fraley’s novel technology is that it will assess all the diverse bacterial DNA present in a sample, without presuming which genetic material is important. “Bacteria are constantly evolving and becoming drug resistant,” she said. “With this technology, we can see all the bacterial DNA that is present individually and not just the strains we THINK we need to look for.”

Fraley’s award will follow her wherever her career takes her. The first two years of the prize fund postdoctoral training and that last three years help launch her professional career in academia. During the application process, she had to make a short presentation on her proposal to BWF’s panel of experts. “It was like the television show ‘Shark Tank’ but for scientists,” she laughs. “ The panelists gave me many helpful suggestions on my idea.”

Fraley earned her bachelor’s degree in chemical engineering from the University of Tennessee at Chattanooga and her doctorate in chemical and biomolecular engineering with Denis Wirtz, professor and director of Johns Hopkins Physical Sciences-Oncology Center. Wirtz is associate director for the Institute for NanoBioTechnology and Yang and Wang also are INBT affiliated faculty members.

BWF’s Career Awards at the Scientific Interface provides funding to bridge advanced postdoctoral training and the first three years of faculty service. These awards are intended to foster the early career development of researchers who have transitioned or are transitioning from undergraduate and/or graduate work in the physical/mathematical/computational sciences or engineering into postdoctoral work in the biological sciences, and who are dedicated to pursuing a career in academic research. These awards are open to U.S. and Canadian citizens or permanent residents as well as to U.S. temporary residents.

INBT professional development seminars schedule announced

As an outreach to its students and the university community at large, Johns Hopkins Institue for NanoBioTechnology offers four professional development seminars during the summer.  All seminars are held on select Wednesdays in Remsen 101 from 10:45am – 12pm.

The seminar schedule is as follows:

  • June 12 – Topic: I got my PhD, now what? A panel discussion 

Panel: Justin Galloway, PhD, Entrepreneurship; Associate Professor of Chemical and Biomolecular Engineering Honggang Cui, Academia; Kate Malachowski, ChemBE doctoral candidate, Industry/ Government; Ramsay Kraya, postdoctoral fellow in the Searson Lab, materials science and engineering

  • June 26 – Topic: How to promote yourself and the benefits of networking

Speaker: Tom Fekete, INBT’s director of corporate partnerships

  • July 10 – Topic: Why you should consider grad school and how do you prepare?

Speaker: Eric Hall,  associate director of the JHU Career Center

  • July 24 – Topic: INBT Film Festival, featuring short films made by students in Science Communication for Scientists and Engineers

Hosted by: Mary Spiro, INBT’s science writer

No RSVP is needed. The seminars are free and open to university students, faculty, staff and visitors.

Landmark physical characterization of cancer cells completed

An enormous collaborative effort between a multitude of academic and research centers has characterized numerous physical and mechanical properties on one identical human cancer cell line. Their two-year cooperative study, published online in the April 26, 2013 journal Science Reports, reveals the persistent and agile nature of human cancer cells as compared to noncancerous cells. It also represents a major shift in the way scientific research can be accomplished.

Human breast cancer cells like these were used in the study. (Image created by Shyam Khatau/ Wirtz Lab)

Human breast cancer cells like these were used in the study. (Image created by Shyam Khatau/ Wirtz Lab)

The research, which was conducted by 12 federally funded Physical Sciences-Oncology Centers (PS-OC) sponsored by the National Cancer Institute, is a systematic comparison of metastatic human breast-cancer cells to non-metastatic breast cells that reveals dramatic differences between the two cell lines in their mechanics, migration, oxygen response, protein production and ability to stick to surfaces. They have also discovered new insights into how human cells make the transition from nonmalignant to metastatic, a process that is not well understood.

Denis Wirtz, a Johns Hopkins professor of chemical and biomolecular engineering with joint appointments in pathology and oncology who is the corresponding author on the study, remarked that the work adds a tremendous amount of information about the physical nature of cancer cells. “For the first time ever, scientists got together and have created THE phenotypic signature of cancer” Wirtz said. “Yes, it was just one metastatic cell line, and it will require validation with many other cell lines. But we now have an extremely rich signature containing many parameters that are distinct when looking at metastatic and nonmetastatic cells.”

Wirtz, who directs the Johns Hopkins Physical Sciences-Oncology Center, also noted the unique way in which this work was conducted: all centers used the same human cell line for their studies, which makes the quality of the results unparalleled. And, since human and not animal cells were used, the findings are immediately relevant to the development of drugs for the treatment of human disease.

“Cancer cells may nominally be derived from the same patient, but in actuality they will be quite different because cells drift genetically over just a few passages,” Wirtz said.  “This makes any measurement on them from different labs like comparing apples and oranges.” In this study, however, the genetic integrity of the cell lines were safeguarded by limiting the number times the original cell cultures could be regrown before they were discarded.

The nationwide PS-OC brings together researchers from physics, engineering, computer science, cancer biology and chemistry to solve problems in cancer, said Nastaran Zahir Kuhn, PS-OC program manager at the National Cancer Institute.

“The PS-OC program aims to bring physical sciences tools and perspectives into cancer research,” Kuhn said. “The results of this study demonstrate the utility of such an approach, particularly when studies are conducted in a standardized manner from the beginning.”

For the nationwide project, nearly 100 investigators from 20 institutions and laboratories conducted their experiments using the same two cell lines, reagents and protocols to assure that results could be compared. The experimental methods ranged from physical measurements of how the cells push on surrounding cells to measurements of gene and protein expression.

“Roughly 20 techniques were used to study the cell lines, enabling identification of a number of unique relationships between observations,” Kuhn said.

Wirtz added that it would have been logistically impossible for a single institution to employ all of these different techniques and to measure all of these different parameters on just one identical cell line. That means that this work accomplished in just two years what might have otherwise taken ten, he said.

The Johns Hopkins PS-OC made specific contributions to this work. Using particle-tracking microrheology, in which nanospheres are embedded in the cell’s cytoplasm and random cell movement is visually monitored, they measured the mechanical properties of cancerous versus noncancerous cells. They found that highly metastatic breast cancer cells were mechanically softer and more compliant than cells of less metastatic potential.

Using 3D cell culturing techniques, they analyzed the spontaneous migratory potential (that is, migration without the stimulus of any chemical signal) of cancerous versus noncancerous cells. They also analyzed the extracellular matrix molecules that were deposited by the two cell lines and found that cancerous cells deposited more hyaluronic acid (HA). The HA, in turn, affects motility, polarization and differentiation of cells.  Finally, the Hopkins team measured the level of expression of CD44, a cell surface receptor that recognizes HA, and found that metastatic cells express more CD44.

The next steps, Wirtz said, would be to validate these results using other metastatic cell lines.  To read the paper, which is published in an open access journal, follow this link:

Excerpts from original press release by Princeton science writer Morgan Kelly were used.





Recent publications from the Johns Hopkins Physical Sciences-Oncology Center

Johns Hopkins Physical Sciences-Oncology Center has had a productive quarter publishing from February to May 2013. Here are some of the most recent publications in support or the center’s core research projects, including a huge collaborative work drawing on the knowledge and research findings of the entire PS-OC network.

Screen Shot 2013-05-15 at 4.27.37 PMThat paper, A physical sciences network characterization of non-tumorigenic and metastatic cells, was the work of 95 authors from all 12 of the National Cancer Institute’s PS-OC  program centers. JHU’s PS-OC director Denis Wirtz, the Theophilus H. Smoot Professor in the Johns Hopkins Department of Chemical and Ciomolecular Engineering, is the corresponding author on this massive effort. We will be discussing the findings of that paper in a future post here on the PS-OC website. Until then, here is a link to that network paper and 13 other recent publications from the Johns Hopkins PS-OC.

  • A physical sciences network characterization of non-tumorigenic and metastatic cells.Physical Sciences – Oncology Centers Network, Agus DB, Alexander JF, Arap W,Ashili S, Aslan JE, Austin RH, Backman V, Bethel KJ, Bonneau R, Chen WC,Chen-Tanyolac C, Choi NC, Curley SA, Dallas M, Damania D, Davies PC, Decuzzi P,Dickinson L, Estevez-Salmeron L, Estrella V, Ferrari M, Fischbach C, Foo J,Fraley SI, Frantz C, Fuhrmann A, Gascard P, Gatenby RA, Geng Y, Gerecht S,Gillies RJ, Godin B, Grady WM, Greenfield A, Hemphill C, Hempstead BL, HielscherA, Hillis WD, Holland EC, Ibrahim-Hashim A, Jacks T, Johnson RH, Joo A, Katz JE,Kelbauskas L, Kesselman C, King MR, Konstantopoulos K, Kraning-Rush CM, Kuhn P,Kung K, Kwee B, Lakins JN, Lambert G, Liao D, Licht JD, Liphardt JT, Liu L, LloydMC, Lyubimova A, Mallick P, Marko J, McCarty OJ, Meldrum DR, Michor F,Mumenthaler SM, Nandakumar V, O’Halloran TV, Oh S, Pasqualini R, Paszek MJ,Philips KG, Poultney CS, Rana K, Reinhart-King CA, Ros R, Semenza GL, Senechal P,Shuler ML, Srinivasan S, Staunton JR, Stypula Y, Subramanian H, Tlsty TD, TormoenGW, Tseng Y, van Oudenaarden A, Verbridge SS, Wan JC, Weaver VM, Widom J, Will C, Wirtz D, Wojtkowiak J, Wu PH.  Sci Rep. 2013 Apr 25;3:1449. doi:10.1038/srep01449. PubMed PMID: 23618955; PubMed Central PMCID: PMC3636513.
  • Procollagen Lysyl Hydroxylase 2 Is Essential for Hypoxia-Induced Breast Cancer Metastasis. Gilkes DM, Bajpai S, Wong CC, Chaturvedi P, Hubbi ME, Wirtz D, Semenza GL.Mol Cancer Res. 2013 May 7. [Epub ahead of print] PubMed PMID: 23378577.
  • Predicting how cells spread and migrate: Focal adhesion size does matter. Kim DH, Wirtz D. Cell Adh Migr. 2013 Apr 29;7(3). [Epub ahead of print] PubMed PMID: 23628962.
  • Hypoxia-inducible Factor 1 (HIF-1) Promotes Extracellular Matrix Remodeling under Hypoxic Conditions by Inducing P4HA1, P4HA2, and PLOD2 Expression in Fibroblasts. Gilkes DM, Bajpai S, Chaturvedi P, Wirtz D, Semenza GL. J Biol   Chem. 2013 Apr 12;288(15):10819-29. doi: 10.1074/jbc.M112.442939. Epub 2013 Feb 19. PubMed PMID: 23423382; PubMed Central PMCID: PMC3624462.
  • Perivascular cells in blood vessel regeneration. Wanjare M, Kusuma S, Gerecht S. Biotechnol J. 2013 Apr;8(4):434-47. doi: 10.1002/biot.201200199. PubMed PMID: 23554249.
  • Focal adhesion size uniquely predicts cell migration. Kim DH, Wirtz D. FASEB J. 2013 Apr;27(4):1351-61. doi: 10.1096/fj.12-220160. Epub 2012 Dec 19. PubMed PMID: 23254340; PubMed Central PMCID: PMC3606534.
  • Notch4-dependent Antagonism of Canonical TGFβ1  Signaling Defines Unique Temporal Fluctuations of SMAD3 Activity in Sheared Proximal Tubular Epithelial Cells. Grabias BM, Konstantopoulos K. Am J Physiol Renal Physiol. 2013 Apr 10. [Epub ahead of print] PubMed PMID: 23576639.
  • Integration and regression of implanted engineered human vascular networks during deep wound healing. Hanjaya-Putra D, Shen YI, Wilson A, Fox-Talbot K, Khetan S, Burdick JA, Steenbergen C, Gerecht S. Stem Cells Transl Med. 2013 Apr;2(4):297-306. doi: 10.5966/sctm.2012-0111. Epub 2013 Mar 13. PubMed PMID: 23486832.
  • Collagen Prolyl Hydroxylases are Essential for Breast Cancer Metastasis. Gilkes DM, Chaturvedi P, Bajpai S, Wong CC, Wei H, Pitcairn S, Hubbi ME, Wirtz D, Semenza GL. Cancer Res. 2013 Mar 28. [Epub ahead of print] PubMed PMID: 23539444.
  • Simultaneously defining cell phenotypes, cell cycle, and chromatin modifications at single-cell resolution.Chambliss AB, Wu PH, Chen WC, Sun SX, Wirtz D.FASEB J. 2013 Mar 28. [Epub ahead of print] PubMed PMID: 23538711.
  • Interstitial friction greatly impacts membrane mechanics. Wirtz D. Biophys J.2013 Mar 19;104(6):1217-8. doi: 10.1016/j.bpj.2013.02.003. Epub 2013 Mar 19.PubMed PMID: 23528079; PubMed Central PMCID: PMC3602747.
  • Functional interplay between the cell cycle and cell phenotypes. Chen WC, Wu PH, Phillip JM, Khatau SB, Choi JM, Dallas MR, Konstantopoulos K,Sun SX, Lee JS, Hodzic D, Wirtz D.Integr Biol (Camb). 2013 Mar;5(3):523-34. doi:10.1039/c2ib20246h. PubMed PMID: 23319145
  • High-throughput secretomic analysis of single cells to assess functional cellular heterogeneity. Lu Y, Chen JJ, Mu L, Xue Q, Wu Y, Wu PH, Li J, Vortmeyer AO, Miller-Jensen K, Wirtz D, Fan R. Anal Chem. 2013 Feb 19;85(4):2548-56. doi:10.1021/ac400082e. Epub 2013 Feb 1. PubMed PMID: 23339603; PubMed Central PMCID:  PMC3589817.\


Microscopic grippers used successfully in animal biopsies

Tiny, untethered microscale grippers have been successfully used to perform tissue biopsies in live animals, a study in the journal Gastroenterology reports. Researchers affiliated with the Johns Hopkins School of Medicine, Whiting School of Engineering and Institute for NanoBiotechnology developed the self-assembling microgrippers, called mu-grippers. The star-shaped devices use the animal’s own body heat to trigger them to clamp down around tissue to grab a sample like a tiny hand. Because the grippers are magnetic, they can later be retrieved for a minimally invasive procedure.

Dozens of dust-sized surgical mu- grippers in a vial. (Photo by  Evin Gultepe, Gracias Lab, Johns Hopkins University)

Dozens of dust-sized surgical mu- grippers in a vial. (Photo by Evin Gultepe, Gracias Lab, Johns Hopkins University)

David Gracias, the principal investigator for the study and associate professor of chemical and biomolecular engineering, was quoted in a Johns Hopkins press release about the work: “This is the first time that anyone has used a sub-millimeter-sized device — the size of a dust particle — to conduct a biopsy in a live animal … That’s a significant accomplishment. And because we can send the grippers in through natural orifices, it is an important advance in minimally invasive treatment and a step toward the ultimate goal of making surgical procedures noninvasive.”

Read more here.


Regenerative medicine theme of science-writer bootcamp

Screen Shot 2013-04-01 at 3.19.05 PMJohns Hopkins invites you to the fifth annual science-writer boot camp. This year’s topic will be Regenerative Medicine. Join Johns Hopkins experts in regenerative medicine to learn the latest in stem cell research, tissue regeneration and organ transplantation.

Three of the 11 presenters are affiliated faculty members of the Johns Hopkins Institute for NanoBioTechnology. This event is sponsored by the Johns Hopkins Institute for Basic Biomedical Sciences.  There is no cost but reservations are required. Working press as well as freelance writers are invited to attend.

WHAT: Body Building: Recent Advances in Regenerative Medicine

WHEN: Monday, April 29, 2011, 9 a.m. to 4 p.m. (lunch will be provided)

WHERE: Bernstein-Offit Building, room LL7, Johns Hopkins SAIS Campus, 1717 Massachusetts Ave., NW, Washington, D.C. 20036

RSVP: Vanessa McMains at or 410-502-9410 by April 19

Confirmed speakers:

  • Gerald Brandacher, M.D. Scientific Director, Composite Tissue Allotransplantation (Reconstructive Transplant) Program
  • Robert Brodsky, M.D. Director, Division of Hematology
  • Jeff Bulte, Ph.D. Director, Cellular Imaging Section, Institute for Cell Engineering (INBT affiliated faculty)
  • Mark Donowitz, M.D. Director, Center for Epithelial Disorders; Director, Conte GI Core Research Center
  • Gary Gerstenblith, M.D. Professor, Medicine
  • Warren Grayson, Ph.D. Assistant Professor, Biomedical Engineering (INBT affiliated faculty)
  • Jun Liu, Ph.D. Professor, Pharmacology and Molecular Sciences
  • Erika Matunis, Ph.D. Associate Professor, Cell Biology
  • Guo-li Ming, M.D., Ph.D. Professor, Neurology and member of the Institute for Cell Engineering (INBT affiliated faculty)
  • Ronald Schnaar, Ph.D. Professor, Pharmacology and Molecular Sciences; Director, Lung Inflammatory Disease Program of Excellence in Glycoscience

We look forward to seeing you on April 29!

Download the color flyer here.