A new study published in the Online Early Edition of Proceedings of the National Academy of Sciences reveals that Johns Hopkins researchers have developed a synthetic protein, which, when activated under ultraviolet lighting, can show doctors exactly where certain medical disorders are located, such as arthritis and cancer.
This amazing breakthrough paves way to a new kind of diagnostic imaging technology and may eventually lead to doctors being able to insert medication in places where the the imaging has detected disease.
During the trial, the experts were successful in using the synthetic protein to find prostate and pancreatic cancer in mouse models. They also were able to find bone growth abnormalities consistent with Marfan syndrome.
The authors note that the synthetic protein does not pinpoint exactly where the diseased cells are. However, it connects to damaged collagen near the diseased site.
Collagen is the body's most prevalent protein. Its main job is to provide a structured environment in which cells can build skin, bone and nerves. The scientists say that damaged collagen is normal, but cancer and other diseased cells can hurt collagen faster than usual. Because of all this damage that cancer and other disease cause, the synthetic protein can do its job in finding the site that needs help.
S. Michael Yu, a faculty member from the Whiting School of Engineering's Department of Materials Science and Engineering commented:
"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. Instead of looking for the burglars, our synthetic protein is reacting to evidence left at the scene of the crime."
Martin Pomper, co-principal investigator of the Johns Hopkins Center of Cancer Nanotechnology Excellence and a School of Medicine professor of radiology met Yu while they were both involved in the Johns Hopkins Institute for NanoBioTechnology.
"A major unmet medical need is for a better non-invasive characterization of disrupted collagen, which occurs in wide variety of disorders. 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 that were used during the study are collagen mimetic peptides (CMPs). These certain types of proteins are naturally pulled in the direction of disease damaged collagen, where they then attach themselves.
For the doctors to be able to see where the proteins are traveling, they place fluorescent tags on every CMP so it will be easy to detect with the imaging technology. Wherever the area is glowing, it is an indication of collagen that has most likely been damaged by disease.
At the beginning of the trial, the scientists thought they might have a problem because the CMPs would often cling to each other instead of the damaged collagen, making it difficult for them to distinguish the areas in need of treatment.
In order to fix this issue, Yang Li, a doctoral student from the Department of Chemistry in the Krieger School of Arts and Sciences at Johns Hopkins and the lead author of the study, developed CMPS which had a chemical box around it, therefore prohibiting the binding between proteins. Right before the protein is entered into the blood, the scientist used the ultraviolet lighting to "unlock" the box and CMPs can then continue their mission in finding the diseased area.
To test Li's method,Yu and his team injected the proteins into mice that were infected with pancreatic and prostate human cancer cells.
Over a 4 day span, fluorescent images were taken which showed researchers were able to watch strands of the synthetic protein, which was traveling through the tumor areas by means of blood vessels and sticking itself to cancer damaged collagen.
Tests similar to this one have shown that CMP may be able to detect the site of cartilage and bones which are harvesting high levels of damaged collagen as well. This would lead to treatment and diagnosis of bone and cartilage damage.
The authors note that this method is not completely understood yet, however, finding and rebuilding collagen will help promote bone growth in patients who are suffering with Marfan syndrome, and could lead to major breakthroughs in the future.
Written by Christine Kearney