By: Kevin Murnane
A recently developed liquid biopsy that makes use of carbon nanotube (CNT) semiconductors is a promising technology that may increase the likelihood of early detection for a range of different types of cancer. The research was carried out by a team from Worcester Polytechnic Institute, the University of Louisville and Thomas Jefferson University and was reported in the journal Nanotechnology.
Liquid biopsies use a blood sample to detect cancer cells or genetic material from cancer cells that are circulating in the bloodstream. They are obviously much less invasive than surgical biopsies because they only involve taking a blood sample. They are also especially good for early detection because they can detect the presence of cancer before a tumor is noticed and before the cancer has metastasized.
There are a number of different methods for performing a liquid biopsy. For example, microfluidic liquid biopsies capture cancer cells as blood flows past detectors. The success of this method depends on the flow rate. Faster blood flow reduces the chance of detection because the cancerous cells are swept past the detectors before they can be captured.
The CNT liquid biopsy uses a deceptively simple approach that avoids this problem by detecting cancer cells in a stationary drop of blood that is placed on a CNT semiconductor chip. The chip has an array of CNT semiconductors that sit at the bottom of shallow wells. Cancer cells are relatively dense and they sink to the bottom of the wells where they come into contact with antibodies that are attached to the CNTs. The antibodies bind to the cancer cells which triggers a change in electrical conductance on the CNT chip. If cancer cells are present, the signal from the chip can tell the diagnostician what type of cancer it is.
The CNT liquid biopsy was tested with samples of blood that were spiked with two types of mammary gland adenocarcinoma cells. Antibodies that bind to the two different types of cells were attached to the CNTs. Each antibody captured its associated type of cancer cell and cell capture varied from 55% to 100% depending on the size of the area of contact between the CNT chips and the blood drops.
Liquid biopsies that use CNT chips have several positive features. For example, multiple cancers can be detected with one liquid biopsy by attaching a range of cancer-specific antibodies to different CNTs. Another benefit is that the CNT liquid biopsies can be carried out in minutes which means patient anxiety can be quickly relieved if no cancer is detected.
The CNT liquid biopsy reported in the Nanotechnology article is a proof-of-concept that looks promising. My wife and I were very fortunate that her breast cancer was detected so early. With further refinement, the CNT liquid biopsy may turn what was a lucky break for us into a normal occurrence for others.
Barbara Jacoby is an award winning blogger that has contributed her writings to multiple online publications that have touched readers worldwide.