"A Glucose BioFuel Cell Implanted in Rats"

Within the last few months, a group of researchers at Joseph Fourier University in France have developed a BioFuel Cell that uses glucose as an electrical energy source. While so called BioFuel cells have been produced that use enzymes to oxidize glucose molecules, they have been up until this point only able to function in vitro as they use enzymes that function at non-physiological conditions, namely at a low pH and in very specific buffer solutions. While the performance of this cell is highest in vitro, it is nonetheless able to function at a significant power level in vivo when the researchers used rats as test subjects. The power produced is on the order of milliwatts, but this is on a similar order of magnitude as what is required by many implants, including heart pacemakers.

In addition to functioning at physiological conditions, the fuel cells are noteworthy for being exceptionally biocompatible. The section of the implant containing the enzymes was not rejected by the rat’s immune system and, on the contrary, was enveloped by a neo-vascular network of tissue. Also, the byproducts of the glucose oxidation, namely H2O2 and other free radicals, were converted to more biologically acceptable chemicals like water by additional enzymes. This means the waste products have minimal impact on the health of the subject.

I find this article interesting because using chemicals already present in an organism as a power source has a wide array of applications, including replacing metal-based battery implants in favor of more biocompatible, and possibly longer-lived, fuel cells. With an ever increasing amount of implants requiring power being used in treating certain diseases, particularly heart disease and diabetes, it is becoming more of a priority to develop power supply systems that are compatible with a living organism and do not need to be replaced every few years, minimizing surgeries. As a side note, it is my personal opinion that developing electric cells which function in the ECF of organisms can be based off of living cells. This can likely be derived from mimicking or even implementing ion pumps found in cell membranes to create electric potentials across the power cell. Examining the way electrocytes function in organisms like electric eels may also prove enlightening. It goes without saying that I look forward to helping pioneer this particular field of biomedical engineering.

Reference: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2864295/

Austin Butts, VTPP 434-502