Circulating tumor cells (CTCs) cause metastases of cancer, but can have a redeeming quality if we can use them as biomarkers for these cancers. For most neoplasms, biopsies are performed to definitively diagnose the disease, but circulating tumor cells offer the possibility of "liquid biopsies" that require only blood collection.
Researchers at the University of Michigan have now developed a wearable device that can continuously track total blood for CTCs and make them available for inspection by pathologists.
"Nobody wants to do a biopsy. If we could get enough cancer cells from the blood, we could use them to learn about the biology of the tumor and direct care to the patients. That's the thrill of why we're doing it, "said Daniel F. Hayes, MD, senior author of the study, in a statement.
Catching CTCs is difficult because of how rare they are. Typically, a blood sample is collected and a highly sensitive device is used to identify the few CTCs within that sample. The new M U device stays with the patient for a long period of time, so you have the chance to actually use a lot more blood for your sample.
Also, since the tumor does not always release the same amount of CTCs, a sample obtained at any time may have very few target cells to find. The new device can collect samples as often as needed, which should help prevent precision problems related to blood collection time.
So far, the technology has been tested on dogs that have received injections of human CTCs (do not worry, this has not led to cancer in these dogs). The wearable device was set up to collect samples every 20 minutes and, in fact, located the CTCs. It was small enough for dogs to wear for a period of hours, and could be turned into a simple bracelet that a patient could wear.
Some details about what the research team needed to do to achieve this latest development, according to U of M:
They developed protocols to mix blood with heparin, a drug that prevents clotting, and sterilization methods that killed the bacteria without damaging the immune markers, or antibodies, on the chip. Kim also packaged some of the smallest medical grade pumps in a 3D printed box with the electronics and the cancer cell capture chip.
The chip itself is a novelty in one of the devices with the highest capture rate in Nagrath's lab. It uses graphene oxide nanomaterial to create dense forests of antibody-tipped molecular chains, allowing it to trap more than 80% of the cancer cells in the whole blood that flows through it. The chip can also be used to grow captured cancer cells, producing larger samples for further analysis.
Study in Communications of nature: A temporary intravascular aphaerectic system for in vivo enrichment of circulating tumor cells …
Via: University of Michigan …