- Cancer detection can be improved by using imaging techniques with nanoparticles loaded with contrast dyes
- Commonly used tattoo inks and food dyes approved by the FDA have interesting optical properties that can be exploited for imaging
- Nanoparticles loaded with commonly used dyes accumulate in the tumor and under imaging they function with better selectivity and sensitivity
Tattoo ink and common food dyes could play an important role in the detection of cancer, according to a new research study.
The research work has been published in Biomaterials Science .
Detection of cancer can be challenging without good imaging agents. These imaging agents, when injected into the patients, allow imaging such as MRI and CT to function efficiently with sensitivity and specificity.
These images allow medical professionals to diagnose cancer with accuracy and for surgeons to identify the exact margins of the tumors.
Colon cancer is detected with endoscopy. An endoscopy will only give information about the structure of the colon. If a polyp is seen, a further biopsy would be needed.
Usage of imaging tools would help doctors to observe the polyp and understand if that particular polyp is cancerous or benign. This observation would determine further treatment options.
Cancer Detection using Tattoo Ink and Food Dyes
The research team discovered optical contrasting agents from household coloring dyes and pigments.
The coloring dyes were incorporated into nanoparticles which would move through a blood vessel to find cancer.
The inspiration for using tattoo inks struck Christina Zavaleta in an unusual place- an animation class with Pixar artists. She was intrigued by the paints and inks that the artists had brought to the class.
She wondered if these high pigment paints would have interesting optical properties. This idea led her to a tattoo artist, Adam Sky, who works with bright dyes.
"I remember I brought a 96-well plate and he squirted tattoo ink into each of the wells," Zavaleta said.
"Then I took the inks to our Raman scanner (used to detect the tumor-targeting nanoparticles) and discovered these amazing spectral fingerprints that we could use to barcode our nanoparticles. "
One of the safety challenges when using nanoparticles is that often they have prolonged retention in liver and spleen, organs which are responsible for their break down.
It is crucial to consider biodegradable nanoparticles for safety concerns.
As there are only a few optical contrast agents for clinical use, the research team considered common food dyes that have been approved by the FDA.
The research team found many FDA-approved drugs that have interesting optical properties that they could exploit for imaging.
The research team designed nanoparticles which would carry these highly pigmented imaging agents as a 'payload'. The particles are of a specific size where they would passively penetrate the tumor and be retained. The contrasting agents they used were small molecule dyes.
"With small molecules, you may be able to see them accumulate in tumor areas initially, but you would have to be quick before they end up leaving the tumor area to be excreted," Zavaleta said.
"Our nanoparticles happen to be small enough to seep through, and big enough to be retained in the tumor, and that is what we call the enhanced permeability and retention effect."
The nanoparticle could also be decorated using a larger payload than small molecule imaging agents. These particles under fluorescent imaging provide a brighter signal and significant localization in the tumors.
In summary, the researchers have developed an efficient dye-based nanoparticle that could help in the detection of cancers.