Light-activated synthetic protein illuminates disease destruction

Illustration of collagen’s rope-like structure. Click to watch video. (INBT Animation Studios)

Johns Hopkins researchers have created a synthetic protein that, when activated by ultraviolet light, can guide doctors to places within the body where cancer, arthritis and other serious medical disorders can be detected. The synthetic protein does not zero in directly on the diseased cells. Instead, it binds to nearby collagen that has been degraded by disease or injury.

“These disease cells are like burglars who break into a house and do lots of damage but who are not there when the police arrive,” said S. Michael Yu, a faculty member in the Whiting School of Engineering’s Department of Materials Science and Engineering. “Instead of looking for the burglars, our synthetic protein is reacting to evidence left at the scene of the crime,” said Yu, who was principal investigator in the study.

The technique could lead to a new type of diagnostic imaging technology and may someday serve as a way to move medications to parts of the body where signs of disease have been found. In a study published in the Aug. 27-31 Online Early Edition of Proceedings of the National Academy of Sciences, the researchers reported success in using the synthetic protein in mouse models to locate prostate and pancreatic cancers, as well as to detect abnormal bone growth activity associated with Marfan syndrome.

Collagen, the body’s most abundant protein, provides structure and creates a sturdy framework upon which cells build nerves, bone and skin. Some buildup and degradation of collagen is normal, but disease cells such as cancer can send out enzymes that break down collagen at an accelerated pace. It is this excessive damage, caused by disease, that the new synthetic protein can detect, the researchers said.

A key collaborator was Martin Pomper, a School of Medicine professor of radiology and co-principal investigator of the Johns Hopkins Center of Cancer Nanotechnology Excellence. Pomper and Yu met as fellow affiliates of the Johns Hopkins Institute for NanoBioTechnology. “A major unmet medical need is for a better non-invasive characterization of disrupted collagen, which occurs in a wide variety of disorders,” Pomper said. “Michael has found what could be a very elegant and practical solution, which we are converting into a suite of imaging and potential agents for diagnosis and treatment.”

The synthetic proteins used in the study are called collagen mimetic peptides or CMPs. These tiny bits of protein are attracted to and physically bind to degraded strands of collagen, particularly those damaged by disease. Fluorescent tags are placed on each CMP so that it will show up when doctors scan tissue with fluorescent imaging equipment. The glowing areas indicate the location of damaged collagen that is likely to be associated with disease.

In developing the technique, the researchers faced a challenge because CMPs tend to bind with one another and form their own structures, similar to DNA, in a way that would cause them to ignore the disease-linked collagen targeted by the researchers.

To remedy this, the study’s lead author, Yang Li, synthesized CMPs that possess a chemical “cage” to keep the proteins from binding with one another. Just prior to entering the bloodstream to search for damaged collagen, a powerful ultraviolet light is used to “unlock” the cage and allow the CMPs to initiate their disease-tracking mission. Li is a doctoral student from the Department of Chemistry in the Krieger School of Arts and Sciences at Johns Hopkins. Yu, who holds a joint appointment in that department, is his doctoral adviser.

Yu’s team tested Li’s fluorescently tagged and caged peptides by injecting them into lab mice that possessed both prostate and pancreatic human cancer cells. Through a series of fluorescent images taken over four days, researchers tracked single strands of the synthetic protein spreading throughout the tumor sites via blood vessels and binding to collagen that had been damaged by cancer.

Similar in vivo tests showed that the CMP can target bones and cartilage that contain large amounts of degraded collagen. Therefore, the new protein could be used for diagnosis and treatment related to bone and cartilage damage.

Although the process is not well understood, the breakdown and rebuilding of collagen is thought to play a role in the excessive bone growth found in patients with Marfan syndrome. Yu’s team tested their CMPs on a mouse model for this disease and saw increased CMP binding in the ribs and spines of the Marfan mice, as compared to the control mice.

Funding for the research was provided by the National Science Foundation, the National Institutes of Health and the Department of Defense. The synthetic protein process used in this research is protected by patents obtained through the Johns Hopkins Technology Transfer Office.

Along with Yu, Li and Pomper, co-authors of this study were instructor Catherine A. Foss and medical resident Collin M. Torok from the Department of Radiology and Radiological Science at the Johns Hopkins School of Medicine; Harry C. Dietz, a professor, and Jefferson J. Doyle, a doctoral student, both of the Howard Hughes Medical Institute and Institute of Genetic Medicine at the School of Medicine; and Daniel D. Summerfield a former master’s student in the Department of Materials Science and Engineering.

Adapted from an original press release by Phil Sneiderman.

 

Light-activated synthetic protein illuminates disease destruction

Illustration of collagen’s rope-like structure. Click to watch video. (INBT Animation Studios)

Johns Hopkins researchers have created a synthetic protein that, when activated by ultraviolet light, can guide doctors to places within the body where cancer, arthritis and other serious medical disorders can be detected. The synthetic protein does not zero in directly on the diseased cells. Instead, it binds to nearby collagen that has been degraded by disease or injury.

“These disease cells are like burglars who break into a house and do lots of damage but who are not there when the police arrive,” said S. Michael Yu, a faculty member in the Whiting School of Engineering’s Department of Materials Science and Engineering. “Instead of looking for the burglars, our synthetic protein is reacting to evidence left at the scene of the crime,” said Yu, who was principal investigator in the study.

The technique could lead to a new type of diagnostic imaging technology and may someday serve as a way to move medications to parts of the body where signs of disease have been found. In a study published in the Aug. 27-31 Online Early Edition of Proceedings of the National Academy of Sciences, the researchers reported success in using the synthetic protein in mouse models to locate prostate and pancreatic cancers, as well as to detect abnormal bone growth activity associated with Marfan syndrome.

Collagen, the body’s most abundant protein, provides structure and creates a sturdy framework upon which cells build nerves, bone and skin. Some buildup and degradation of collagen is normal, but disease cells such as cancer can send out enzymes that break down collagen at an accelerated pace. It is this excessive damage, caused by disease, that the new synthetic protein can detect, the researchers said.

A key collaborator was Martin Pomper, a School of Medicine professor of radiology and co-principal investigator of the Johns Hopkins Center of Cancer Nanotechnology Excellence. Pomper and Yu met as fellow affiliates of the Johns Hopkins Institute for NanoBioTechnology. “A major unmet medical need is for a better non-invasive characterization of disrupted collagen, which occurs in a wide variety of disorders,” Pomper said. “Michael has found what could be a very elegant and practical solution, which we are converting into a suite of imaging and potential agents for diagnosis and treatment.”

The synthetic proteins used in the study are called collagen mimetic peptides or CMPs. These tiny bits of protein are attracted to and physically bind to degraded strands of collagen, particularly those damaged by disease. Fluorescent tags are placed on each CMP so that it will show up when doctors scan tissue with fluorescent imaging equipment. The glowing areas indicate the location of damaged collagen that is likely to be associated with disease.

In developing the technique, the researchers faced a challenge because CMPs tend to bind with one another and form their own structures, similar to DNA, in a way that would cause them to ignore the disease-linked collagen targeted by the researchers.

To remedy this, the study’s lead author, Yang Li, synthesized CMPs that possess a chemical “cage” to keep the proteins from binding with one another. Just prior to entering the bloodstream to search for damaged collagen, a powerful ultraviolet light is used to “unlock” the cage and allow the CMPs to initiate their disease-tracking mission. Li is a doctoral student from the Department of Chemistry in the Krieger School of Arts and Sciences at Johns Hopkins. Yu, who holds a joint appointment in that department, is his doctoral adviser.

Yu’s team tested Li’s fluorescently tagged and caged peptides by injecting them into lab mice that possessed both prostate and pancreatic human cancer cells. Through a series of fluorescent images taken over four days, researchers tracked single strands of the synthetic protein spreading throughout the tumor sites via blood vessels and binding to collagen that had been damaged by cancer.

Similar in vivo tests showed that the CMP can target bones and cartilage that contain large amounts of degraded collagen. Therefore, the new protein could be used for diagnosis and treatment related to bone and cartilage damage.

Although the process is not well understood, the breakdown and rebuilding of collagen is thought to play a role in the excessive bone growth found in patients with Marfan syndrome. Yu’s team tested their CMPs on a mouse model for this disease and saw increased CMP binding in the ribs and spines of the Marfan mice, as compared to the control mice.

Funding for the research was provided by the National Science Foundation, the National Institutes of Health and the Department of Defense. The synthetic protein process used in this research is protected by patents obtained through the Johns Hopkins Technology Transfer Office.

Along with Yu, Li and Pomper, co-authors of this study were instructor Catherine A. Foss and medical resident Collin M. Torok from the Department of Radiology and Radiological Science at the Johns Hopkins School of Medicine; Harry C. Dietz, a professor, and Jefferson J. Doyle, a doctoral student, both of the Howard Hughes Medical Institute and Institute of Genetic Medicine at the School of Medicine; and Daniel D. Summerfield a former master’s student in the Department of Materials Science and Engineering.

Adapted from an original press release by Phil Sneiderman.

 

INBT Seminar Aug. 22: New Questions in Aging

Everyone ages; it’s a fact. But as we age, must we also get sick? Scientists, engineers and clinicians are studying how cells change as we age. What they learn may help prevent the onset of disease.

Johns Hopkins Institute for NanoBioTechnology will host a half-day seminar “New Questions in Aging,” Aug. 22 from 10 a.m. until noon in the Hackerman Hall Auditorium (B-17).

Speakers include experts in the field of aging research.

Felipe Sierra

Felipe Sierra, PhD is director of the National Institute of Aging Division of Aging Biology at the National Institutes of Health. He will present the talk “Geroscience: Aging as the Major Risk Factor for Chronic Disease”  from 10-10:45 a.m.

Denis Wirtz, PhD, is the Theophilus H. Smoot Professor in the Chemical and Biomolecular Engineering at Johns Hopkins University and director of the Johns Hopkins Physical Sciences-Oncology Center. His talk is entitled “Single Cell Phenotyping for Studies in Aging;” 10:45 -11:00 a.m.

Denis Wirtz

Jeremy Walston, MD, is the Raymond and Anna Lublin Professor of Geriatric Medicine from the Johns Hopkins University School of Medicine, Division of Geriatric Medicine and Gerontology. His talk is entitled “A Biological Platform for Chronic Disease and Late Life Decline;” 11:00 to 11:15.

Questions and discussion on this interesting topic will follow the talks. This seminar is free and open to the entire Hopkins community. Faculty, students and staff are encouraged to attend for any or all portions of this seminar. For further information about the Johns Hopkins Physical Sciences-Oncology Center, go to http://psoc.inbt.jhu.edu/about/

Jeremy Walston

The Institute for NanoBioTechnology at Johns Hopkins University brings together 223 researchers from the Johns Hopkins Bloomberg School of Public Health, Krieger School of Arts and Sciences, School of Medicine, Applied Physics Laboratory, and Whiting School of Engineering to create new knowledge and new technologies at the interface of nanoscience and medicine.

 

Meet INBT’s summer interns, already digging into their research

Research does not take a holiday during the summer at Johns Hopkins University in Baltimore, Md. In fact, it ramps up with the addition of many new faces from across the country.

The Johns Hopkins Institute for NanoBioTechnology summer research interns have arrived and are already busy at work in various laboratories. This year’s group is the largest the institute has ever hosted, with 17 undergraduates from universities nationwide.

Of the total, three students are affiliated with the Center of Cancer Nanotechnology Excellence and four are affiliated with the Physical Sciences-Oncology Center. The remaining 10 are part of the National Science Foundation Research Experience for Undergraduates program. All are hosted through INBT, which serves as a hub for their academic and social activities.

INBT summer interns conduct 10 weeks of research in a laboratory either on the Homewood or the medical campus of the University. At the end of that time, students have learned how to work in a multidisciplinary team and how to manage a short term research project.  They also discover if research is a pathway they want to pursue after earning their bachelor’s degrees.

In August, interns from many of the science, medicine, engineering and public health summer programs will gather for a  poster session to be held on August 2 at 3 p.m. in Turner Concourse. The poster session will allow students to show off the results of their their work.

This year’s INBT/PS-OC/CCNE interns include:

At the Whiting School of Engineering…

Amani Alkayyali from Wayne State University is an REU student in the laboratory of Honggang Cui assistant professor in the Department of Chemical and Biomolecular Engineering. Also in the Cui lab are CCNE intern Matthew Fong from the University of California, Berkeley and Michelle LaComb, an REU student from Rice University.

Sharon Gerecht, assistant professor in the Department of Chemical and Biomolecular engineering, is hosting three interns. Josh Porterfield of Cornell University and Carolyn Zhang from the University of California are both PS-OC interns, and Bria Macklin of Howard University is an REU intern.

Jacqueline Carozza of Cornell University is a PS-OC student working in the lab of Denis Wirtz, professor in the Department Chemical and Biomolecular Engineering. Cassandra Loren from Oregon State University is a PS-OC intern also working in the Wirtz lab.

Eric Do from the University of Washington is an REU working in the lab of assistant professor Margarita Herrara-Alonso in the Department of Materials Science and Engineering.

Olivia Hentz from Cornell is an REU student working in the lab of Jonah Erlebacher, professor in the Department of Materials Science and Engineering.

Justin Samorajski from the University of Dallas is a returning summer intern, once again working in the materials science and engineering lab of professor Peter Searson as part of the CCNE.

At the School of Medicine…

Lauren Lee of Cornell University is an REU working in the lab of biomedical engineering lab of associate professor Hai-Quan Mao.

Albert Lu from the University of California Berkeley is a CCNE intern working in the biomedical engineering lab of associate professor Jeff Wang.

Bianca Lascano from Norfolk State University is an REU in assistant professor Jordan Green’s biomedical engineering lab.

Charlie Nusbaum of the Richard Stockton College is an REU intern in the radiation oncology lab of assistant professor Robert Ivkov.

At the Krieger School of Arts and Sciences…

Anthony Loder of Rowan University is an REU working in the biology lab of assistant professor Xin Chen.

Daniel McClelland is also REU from Bethany College works in the chemistry laboratory of professor Howard Fairbrother.

 

 

 

 

 

 

 

 

 

In vivo visualization of angiogenesis during wound healing featured on journal cover

Laser speckle contrast images showing (l-r) sequential images of the in vivo blood flow changes that occur on days 0, 3, 5, 7, 10 and 12 after wound creation.

Innovative ways of imaging wound healing can reveal much about blood vessel remodeling and blood flow following an injury. Researchers in the Russell H. Morgan Department of Radiology and Radiological Science and Department of Biomedical Engineering at the Johns Hopkins University School of Medicine have developed a method for using laser speckle contrast imaging (LSCI) to elucidate the changes that occur in the microvasculature over time as a wound heals. Researchers in the laboratory of Arvind P. Pathak have visualized the wound healing process in a mouse ear model by capturing images of angiogenesis—or the development of new blood vessels—over a 12-day period.

“LSCI is a powerful tool for observing the architecture and remodeling of microvasculature as well as the hemodynamic changes (blood flow) during angiogenesis,” said Pathak, an assistant professor of radiology and oncology and principal investigator on the study. “Being able to watch this process occur in a living animal helps us better understand the role of the vasculature during various phases of the wound healing process.”

Stunning images obtained from their experiments were featured on the cover of the March issue of the journal Angiogenesis. The LSCI images shown on the cover from left to right are sequential images of the in vivo blood flow changes that occur on days 0, 3, 5, 7, 10 and 12 after wound creation. The “hotter” colors indicate higher blood flow. The background image is a grayscale LSCI image from an uninjured mouse ear.

Wound healing typically proceeds in three phases, Pathak explained: inflammation (which initiates the immune response and recruits immune cells and molecules to the injury), proliferation (the formation of new blood vessels and epithelium) and remodeling (which removes the vascular scar created during blood vessel formation). LSCI is ideal for imaging the progression of each phase because it can monitor in vivo changes in microvascular architecture and hemodynamics at the same time, he said.

LSCI images are created when tissue illuminated by a laser is photographed through a small aperture, explained Pathak. “The resulting images exhibit a random interference pattern, also called a ‘speckle’ pattern. In blood vessels, this speckle pattern shifts due to the orderly motion of red blood cells, causing a blur over the exposure time of the camera. The degree of blurring in the LSCI image is proportional to the velocity of blood in the vessels and constitutes the biophysical basis of LSCI. Therefore, LSCI can distinguish blood vessels in tissue without any fluorescent dye or contrast agent.”

In this way, Pathak added, LSCI is capable of “wide area mapping” of the tissue, allowing us to measure not only the length and perfusion of blood vessels but their tortuosity (twistiness) and the overall flow of blood to the wound site as healing progresses.

In addition to angiogenesis research, the imaging method has practical applications in drug testing, Pathak said. “Using LSCI alongside a drug study would provide better insight into the efficacy of drug delivery and therapeutic outcome,” he said.

The lead author of the paper was Abhishek Rege, a graduate student in biomedical engineering co-mentored by Pathak and Nitish V. Thakor, professor of biomedical engineering in whose neuroengineering laboratory LSCI was developed. Kevin Rhie, a research technician in Pathak’s laboratory was the other author on this study.

This work was supported jointly by a Johns Hopkins Institute for NanoBiotechnology (INBT) Junior Faculty Pilot Award to Pathak, and grants from the National Institute of Aging and the Department of Health and Human Services to Thakor.

Story by Mary Spiro

Johns Hopkins and UVa co-host 2-day imaging workshop

Learn about state-of-the-art imaging methods at the In Vivo Preclinical Imaging: an Introductory Workshop, March 20-21 at Johns Hopkins University’s School of Medicine Turner Auditorium. Co-hosted by Johns Hopkins University, the University of Virginia and the Society of Nuclear Medicine (SNM), this workshop will bring together gifted lecturers to cover the fundamentals of in vivo small animal imaging.

The workshop will cover an incredible breadth of material of interest and value to physicians, scientists (including postdoctoral fellows and graduate students) and scientific laboratory professionals interested in using molecular imaging for in vivo biomedical applications. Individuals with experience in small animal imaging as well as beginners are welcome. Participants learn the fundamentals of various small animal imaging modalities. A limited number of participants will also have the opportunity to register to attend a half-day, hands on workshop held on the afternoon of the second day, March 21. Registration for this unique opportunity is on first-come first-served, so don’t wait to register.

Speakers will address imaging modalities including MRI and MRS, PET, SPECT, optical imaging (bioluminescence & fluorescence imaging/tomography), ultrasound, x-ray CT, photoacoustic imaging and multimodality imaging. Speakers will also examine instrumentation, acquisition and reconstruction, MR/SPECT/PET imaging probes, targets and applications, small animal handling, techniques for imaging infectious disease models and data analysis.

More information about the workshop, including a full agenda of topics, registration and details about transportation and lodging can be found at the workshop website. www.snm.org/pci2012.

 

INBT launches Johns Hopkins Center of Cancer Nanotechnology Excellence

Martin Pomper and Peter Searson will co-direct INBT’s new Center of Cancer Nanotechnology Excellence (Photo: Will Kirk/Homewood-JHU)

Faculty members associated with the Johns Hopkins Institute for NanoBioTechnology have received a $13.6 million five-year grant from the National Cancer Institute to establish a Center of Cancer Nanotechnology Excellence. The new Johns Hopkins center brings together a multidisciplinary team of scientists, engineers and physicians to develop nanotechnology-based diagnostic platforms and therapeutic strategies for comprehensive cancer care. Seventeen faculty members will be involved initially, with pilot projects adding more participants later.

The Johns Hopkins Center of Cancer Nanotechnology Excellence, which is part of the university’s Institute for NanoBioTechnology, is one of several NCI-supported centers launched through a funding opportunity started in 2005. According to the NCI, the program was established to create “multi-institutional hubs that integrate nanotechnology across the cancer research continuum to provide new solutions for the diagnosis and treatment of cancer.”

Peter Searson, who is the Joseph R. and Lynn C. Reynolds Professor of Materials Science and Engineering in the Whiting School of Engineering and director of the Institute for NanoBioTechnology, will serve as the center’s director. The co-director will be Martin Pomper, professor of radiology and oncology at the School of Medicine and the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins.

“A unique feature of the center is the integration of research, education, training and outreach, and technology commercialization,” Searson said.

To move these new technologies toward use by physicians, a Cancer Nanomedicine Commercialization Working Group will be established and headed by John Fini, director of intellectual property for the university’s Homewood campus. This group will be responsible for managing and coordinating the translational process.

Another special feature of the center will be its Validation Core, led by Pomper, who is also associate director of the Johns Hopkins In Vivo Cellular and Molecular Imaging Center and director of the Johns Hopkins Small Animal Imaging Resource Program.

“Validation is about assuring that the experimental products and results we generate are on target and able to measure the biological effects for which they’re intended,” he said.

Searson and Pomper said the center will consist of four primary research projects.

One project will seek methods to screen bodily fluids such as blood or urine for indicators of cancer found outside of the genetic code, indicators called epigenetic markers. Led by Tza-Huei “Jeff” Wang, associate professor of mechanical engineering in the Whiting School of Engineering; Stephen Baylin, the Virginia and Daniel K. Ludwig Professor of Cancer Research in the School of Medicine; and James Herman, a professor of cancer biology in the School of Medicine, this project will use semiconductor nanocrystals, also known as quantum dots, and silica superparamagnetic particles to detect DNA methylation. Methylation adds a chemical group to the exterior of the DNA and is a biomarker frequently associated with cancer.

A second project, led by Anirban Maitra, associate professor of pathology and oncology at the School of Medicine and the Johns Hopkins Kimmel Cancer Center, will focus on curcumin, a substance found in the traditional Indian spice turmeric. In preclinical studies, curcumin has demonstrated anti-cancer properties but, because of its physical size, it is not readily taken up into the bloodstream or into tissues. Engineered curcumin nanoparticles, however, can more easily reach tumors arising in abdominal organs such as the pancreas, Maitra said. This team will try to determine whether nanocurcumin, combined with chemotherapeutic agents, could become a treatment for highly lethal cancers, such as pancreatic cancer.

Hyam Levitsky, professor of oncology at the Johns Hopkins Kimmel Cancer Center, will lead a third project, which will seek to use a noninvasive method to monitor the effectiveness of vaccines for cancer and infectious diseases.

A final project will build on the work of Justin Hanes and Craig Peacock, professors in the School of Medicine, to deliver therapies directly to small cell lung cancer tissue via mucus-penetrating nanoparticles.

All research efforts will be supported by a nanoparticle engineering core, led by Searson, which will make and characterize a variety of nanomaterials. Another core, centering on bioinformatics and data sharing, will be led by Rafael Irizarry, professor of biostatistics at the Johns Hopkins Bloomberg School of Public Health.

Johns Hopkins Institute for NanoBioTechnology

Sidney Kimmel Comprehensive Cancer Center