217P - Carbon nanotube devices for the detection of circulating tumor cells

Date 30 September 2012
Event ESMO Congress 2012
Session Poster presentation II
Topics Translational Research
Presenter Goetz Kloecker
Authors G. Kloecker1, B. King2, B. Panchapakesan2
  • 1Dept. Medical Oncology & Hematology, Brown Cancer Center University of Louisville, 40205 - Louisville/US
  • 2Department Of Mechanical Engineering, University of Louisville, 40292 - Louisville/US

Abstract

Introduction

Combining clinical and imaging tools with the presence and level of circulating cancer cells (CTC) has great potential. Carbon nanotube electrical devices are a promising technique to detect CTCs in small samples of blood. This study tests, if free energy change for specific interactions is higher than for non-specific interactions. Cell surface receptors found on breast cancer cells are targeted by functionalizing the carbon nanotube electronic devices with cancer-specific antibodies. The study also tested, if the concentration of CTCs correlates with the change in the electronic properties of the nanotube device.

Methods

Antibodies, specific for IGF1R, EPCAM, Her2, and a nonspecific antibody (EMD Biosciences, San Diego CA) in PBS are adsorbed on to the individual nanodevices. One ml drops of fresh human donor blood is mixed with 1 micro-liter of cancer cells (1000 cells). This mixture is applied to the device using a micro-pipette and the change in conductivity is measured. Negative control cell lines that do not overexpress IGF1R, EPCAM, or Her2, such as human Jurkat cells, human nontumorigenic MCF10A cells, and nontumorigenic R- mouse embryonic fibroblast cells with targeted disruption of the IGF1R gene are used as negative controls to test the device efficacy.

Results

Functionalized nanotubes with specific antibodies elicited significant changes in conductivity (10 times change per 100 cells, r∧2 0.95) while non-specific interaction caused negligible conductivity changes. Larger conductivity drops were seen in blood containing cancer cells than blood alone or isolated white blood cells (change in resistance from 2-6 kW for 200 cells in blood, r∧2 0.95). Changes in conductance were linear with an increasing number of cells in the range of 10-300 cells/5 ml. (5 kW per 100 cells, 20 kW per 200 cells and 30 kW per 300 cells, r∧2 0.95).

Conclusion

The specific and proportional changes in conductivity suggest that this approach could be useful in sensing cancer cells in a small volume of blood. Monitors based on nano-technology may be of clinical utility in the detection of a wide variety of cancer types. This non-invasive test would give clinicians immediate results (similar to a glucometer), which can improve screening, response assessment and surveillance.

Disclosure

All authors have declared no conflicts of interest.