A temporary tattoo could help control chronic autoimmune diseases such as multiple sclerosis in near future, reports a study involving nanoparticles and conducted at Rice University.
Generally, autoimmune diseases are treated by immunosuppressant drugs that suppress the immune system altogether, including T lymphocyte, B lymphocyte and macrophages. When the immune system is greatly compromised, it elevates the risk of infection as well as the development of cancer.
While antioxidants help in treating the condition, those obtained from diet are not sufficient for the purpose. Antioxidant carbon nanoparticles that are capable of scavenging reactive oxygen species are more efficient than endogenous and dietary antioxidants. In addition, carbon nanoparticles have affinity toward specific immune cells and the attribute is used by the researchers to develop antibody-based treatment for certain autoimmune diseases.
A team of researchers led by Christine Beeton from Baylor College of Medicine attached carbon nanoparticles to non-toxic polyethylene glycol (PEG-HCC), which are internalized only by T lymphocytes and not by splenic immune cells. These particles form a dark spot when placed under the skin but disappear in one week's time as the particles gradually enter the circulation.
Once in the circulation, the carbon nanoparticles are internalized by T lymphocyte cells, which are responsible for causing diseases like multiple sclerosis. The superoxide formation is the signaling step that indicates that the T-cells are activated. Eventually, the PEG-HCCs present in the system neutralize the superoxide and deactivate them without killing them.
Since the process takes place only between T-cells and carbon nanoparticles, the other immune cells are unaffected and therefore the body's immune system remains healthy and intact. The soluble particles that are developed by the Rice lab of chemist James Tour were tested on rodents in previous studies and were found to show no toxic effects.
Beeton said that PEG-HCCs are released slowly in the body and at the same time don't stay for a long time. Also injecting the nanoparticles under the skin instead of the blood stream helps the particles stay in the body for a longer time. The only disadvantage, the author said, was the black mark left by the particles on the skin.
"We saw it made a black mark when we injected it, and at first we thought that's going to be a real problem if we ever take it into the clinic," said Beeton. "But we can work around that. We can inject into an area that's hidden, or use micropattern needles and shape it. I can see doing this for a child who wants a tattoo and could never get her parents to go along."
The study was published in Nature's online journal Scientific Reports on Sept. 22.
Photo: Michael De Volder | Flickr