Multidrug resistance (MDR)—a process in which tumors
become resistant to multiple medicines—is the main cause of failure
of cancer chemotherapy. Tumor cells often acquire MDR by boosting
their production of proteins that pump drugs out of the cell,
rendering the chemotherapies ineffective. Now, researchers
reporting in ACS’ Nano Letters have developed nanoparticles that
release bursts of calcium inside tumor cells, inhibiting drug pumps
and reversing MDR.