….researchers are hoping to engineer entirely new circuits into cells to help diabetes patients. Martin Fussenegger, a bioengineer at the Swiss Federal Institute of Technology, described a molecular system in which cells are modified with genes that can detect low pH levels in the blood, a sign of a diabetic state. In response, he says, the engineered cells will produce insulin to better regulate blood sugar levels and calm the diabetic state.
This kind of engineering typically depends on viruses to modify genes so that cells will perform useful tasks. But that method is risky: the introduced DNA could integrate into the genome at an unfortunate location that might lead to cancer. Harvey Lodish, a cell biologist at MIT, is working on a technology that could avoid that problem: lab-made red blood cells. After these cells are modified, they will kick out the virus in the course of their natural development process.
“The beauty of red blood cells is they are pretty much the only cell in body without a nucleus,” says Lodish. “By the time they get into circulation, they have lost their DNA and are stable for 120 days with no risk of tumors.”
In Lodish’s method, a retrovirus carries a new gene into the genome of progenitor cells that will eventually produce red blood cells. The cell uses that new gene to produce a modified version of proteins that sit on the surface of the mature red blood cell even after the cell has lost its DNA. The modified surface protein has been engineered so that other compounds can easily be attached to it—antibodies that could mop up toxic substances in the blood, or small-molecule drugs to attack cancers or other diseased cells. Lodish believes the technology is a safer approach to putting synthetic biology to use in the human body.
As Glenn Reynolds of Instapundit says, “faster please”