In a new way to inject drugs, researchers say today they can make bacteria that deliver regular doses of an anticancer toxin deep inside a tumor, usually beyond the reach of conventional chemotherapy. In animal experiments of interest to pharmaceutical companies, the researchers report today in the journal Nature that their genetically engineered bugs can shrink a tumor by directly delivering repeated, synchronized doses of an anti-tumor toxin.
To modulate the drug dose, the researchers engineered the anticancer microbes to grow or self-destruct based on the rise or fall of their overall population, through a technique called quorum sensing.
The bioengineered bacteria burst open in unison to release the toxin. Not all of them die. The survivors grow and seed the next round of attack.