gerard cote a biomedical engineering professor in the dwight look college of engineering is looking for a replacement to the traditional finger-stick monitoring technique people with diabetes need to use every day diabetes is a disease in which the body does not produce or properly use insulin a hormone necessary to convert sugar the bodys basic fuel into energy sugar (glucose) builds up in the blood instead of going to the cells people with diabetes must check their blood sugar levels several times a day to help keep their diabetes under control most monitoring methods require a blood sample obtained by sticking a finger with a needle from an automatic device over the years scientists have been trying to find ways for people with diabetes to measure blood glucose without having to puncture the skin for a blood sample hundreds of research groups worldwide are racing to develop a noninvasive glucose sensor cote said cote is director of the department of biomedical engineerings optical bio-sensing laboratory where research focuses on developing optical diagnostics and sensors for medical applications using lasers fiberoptics and electronics he and his colleagues are investigating new noninvasive ways to test blood sugar levels one of the experimental systems cote is testing involves fluorescent polymer microbeads that could be implanted just under a patients skin glucose levels affect how much light the beads emit which could be measured with a wristwatch-like monitor the research is funded by grants from the state of texas advanced research program and the national science foundation and is administered through the texas engineering experiment station "obviously it isnt totally noninvasive since you need to implant the beads but once theyre in the monitoring process does not involve any daily punctures " cote said the idea got started at a meeting of spie-the international society for optical engineering where cote attended a talk by a physician who removes tattoos with lasers "he said boy wouldnt it be nice if we came up with a way to have a smart tattoo instead of just putting ink particles under the skin that started me thinking " cote said "i got together with michael pishko in the look colleges chemical engineering department we put our heads together and came up with this approach of polymer beads that are implanted just underneath the skin or in the skin layers the beads would glow or fluoresce differently as glucose concentrations changed" the american diabetes association estimates that 17 million people in the united states have diabetes but that one third are unaware they have the disease about 10 percent have type 1 diabetes in which the body fails to produce insulin and which is usually diagnosed in children and young adults an overwhelming 90 percent have type 2 diabetes which develops most often in middle-aged and older adults and results from insulin resistance combined with insulin deficiency pain-free glucose monitoring would make it easier for people with diabetes to check glucose levels throughout the day although pishko is now an associate professor of chemical engineering at penn state university cote continues to collaborate with him on the fluorescent glucose sensor project both researchers recently completed three years on the scientific review committee of the juvenile diabetes research foundation and were honored with the foundations mary ann kugel award for their service the committees members review proposals for diabetes research and advise the foundation on their merits many of the foundations members are parents of children with type 1 diabetes (previously known as juvenile diabetes) cote has heard many of their stories "theres nothing more frustrating to these parents than to see their child break out in a sweat and not know if its because the childs glucose level is too high or if the glucose level is too low one parent said its like his child is near a cliff and he doesnt know if shes walking toward the cliff or away from it" in cotes experimental process two molecular compounds - dextran a macromolecule composed of glucose subunits and concanavalin a (cona) a protein that recognizes sugar - are encapsulated in polyethylene glycol (peg) beads peg is a polymer commonly used for orthopedic implants because of its compatibility with human tissue dextran is tagged with one fluorescent dye color or fluorophore while cona is tagged with another the experimental microgel beads injected just under the skin are too big to enter cells - unlike tattooing in which cells absorb the pigment instead the beads remain in the spaces between the cells called the interstitial spaces fluid in those spaces contains water and glucose molecules small enough to pass through the peg and reach the fluorophore-tagged polymers cote said the level of glucose in interstitial fluid is related to the blood glucose level thats measured by the traditional needle-stick method the dextran molecules bind to the cona molecules together under light from a laser or light-emitting diode they emit a certain color under fluorescence however when glucose enters the picture it competes with dextran displacing the dextran molecules and binding to the cona the fluorescent color changes according to the amount of glucose present in preliminary studies the researchers injected the microbeads under a rats skin and found that the rat tolerated the implant the beads did fluoresce under the rats skin and indicated a change in glucose level "the reason were so optimistic about the fluorescent method is because of its specificity " cote said "we know that if we implant this its going to respond and the response is going to be to glucose with longer-lasting fluorophores the implants could stay under a persons skin for up to a year before having to be replaced "the technology to develop the smart tattoo is here " cote said "its a matter of doing the work and testing the principles" human testing could start within five years this invention is protected under us patent no 6 485 703 issued november 26 2002 the a&m system technology licensing office is currently seeking one or more industrial partners to facilitate commercialization of the procedure for more information about licensing this technology please contact page heller at p-heller@tamuedu or 979-847-8682 please reference tamus project #1240