Abstract

Multidrug resistance (MDR), which is caused by drug efflux via ATP-binding cassette (ABC) transporters, is one of the major obstacles in cancer drug delivery. MDR may be overcome by using inhibitors. But the use of MDR inhibitors unnecessarily may lead to drug toxicity, resulting in failures in previous clinical trials. We now employ a new method called microfluidic single cell biochip (SCB) technology to measure drug uptake in patients’ cancer cells in vitro to determine whether the cancer cells are MDR or not. We measure the drug uptake in the single MDR cancer cells, and its enhancement by using MDR inhibitors. The use of this new SCB method allows us to include patients who would necessarily benefit from MDR inhibitors and exclude patients who do not have MDR at all. Although MDR is an old concept, the use of the SCB method sheds a new hope to reopen clinical trials using MDR inhibitors.