Implantable Glucose Biosensor using Luminescence

[danny333]

My professor has assigned us a project that requires us to design an implantable glucose biosensor that uses the production of ATP from bacteria to produce light with a luciferase enyzme. Bacteria would produce a certain amount of ATP dependent on the amt of glucose in the blood level and that ATP would be converted to light and then sensed by a sensor.

I have a few ideas already, but am really confused:

1) Transform an E. coli cell to contain the luciferase production gene and insert that into the implant.

2) Have semi-permeable membranes that dont allow bacteria to pass thru, but allow glucose and oxygen to freely pass thru

3) Probably use a hydrogel for the implant material to minimize the body's reaction

My major concern and I have no idea how to account for this is the waste of the E. coli and the dead E. coli cells. The cells will constantly produce waste, die off, and replicate.

I was wondering if anyone could think of a way to get rid of the waste and the dead cells within the implant???

-I was thinkin of using a cathoder like system, but I dont know where to dump it. A bag outside the body is impractical and raises sanitary issues.

-I am also concerned on exactly where to implant the biosensor. I was thinkin the abdominal cavity, but my anatomy isnt too good.

I really appreciate any help or ideas anyone could offer. Thank you!

-Dan

[UncleAl]

Uncle Al would gene-gineer glucose oxidase to a peroxide fluorescent protein. Less complexity means fewer FUBARs. Does your prof want the product to work or the mechanism to exercise? ATP does too many things.

http://www.nature.com/nmeth/journal/.../nmeth866.html
http://www.evrogen.com/HyPer.shtml

Thin PDMS rubber (two-component, not hydrolytic cure) is nicely permeable to near everything but cells. 0.1-1% crosslinked poly(N-vinylpyrrolidinone) hydrogel is gentle to cells, but you must copolymerize a hydrophobe to control equilibrium hydration. Methyl methacrylate comonomer gets you blocky Sauflon, which is fragile. N-vinycarbazole comonomer gets you the truly amazing random copolymer Invulneron, which is not fragile.

Configure the device in senescence phase not log growth phase.

How 'bout an insert snugged under the tongue, with a passive RFID-like interface to the outside? Biochips.

[danny333]

well we are kinda limited to makin only what he says and a GFP would only exhibit light under UV conditions....

also how would u go about makin bacteria in the sesecence phase? wouldnt these die relatively quickly? and plus there will never be a lack of nutrients... this implant has to last at least several years which then again leads back to the problem of gettin rid of the dead bacteria?

thanks a lot for the help

[InfiniteNow]

Hey Danny...

You might save yourself some of the work by seeing what's been done already.

http://www.google.com/search?hl=en&q...lucose+monitor

These are the ones I've heard about, and they are trying to incorporate it with insulin pump therapy so the wearer does not have to do any manual programming. Best on the project.