Improvement in the long-term stability of an amperometric glucose sensor system by introducing a cellulose membrane of bacterial origin.
Classical amperometric glucose sensors that use cellulose membranes of wood origin (Cuprophan) suffer from the fact that their long-term stability in blood is short; therefore, their clinical use is limited. In the present study, a classical amperometric glucose sensor was covered with a bacterial cellulose (BC) membrane. Its surface in comparison to that of the classical glucose sensor (Cuprophan) and its long-term stability were tested in vitro and in vivo. The surface element composition was approximately 44% oxygen and approximately 56% carbon in both membranes and thus typical for cellulose. BC membranes exhibited fiber structure, whereas cup membranes did not. There was also a qualitative difference in protein adsorption between both membranes on exposure to bovine serum albumin. Treatment with Trogamid of one site of the BC membranes allowed linear glucose detection between 0 and 40 mM. Hemocompatibility of BC membranes was improved in comparison to cup membranes on the basis of complement activation (C3a and C5a). In diluted blood (1:10), the BC-covered sensor exhibited a long-term stability of more than 200 h; in undiluted blood it was stable for about 24 h, which is about 6-7 times longer than the stability of the classical Cup membrane-covered sensor. In in vivo studies, where the BC membrane-covered sensors were connected to the jugular vein of rats, blood glucose levels could be monitored for at least 24 h. In summary, the use of a modified bacterial cellulose membrane to cover the classical amperometric glucose sensor significantly improves the sensor's long-term stability both in vitro and in vivo.
Department of Pharmacology, University of Tübingen, Germany.
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Ammon
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Ege
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Oppermann
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Gŏpel
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Eisele
D000091:Acetobacter; D000818:Animals; D015374:Biosensing Techniques; D001786:Blood Glucose / Q000032:analysis*; D002482:Cellulose; D004563:Electrochemistry; D005947:Glucose / Q000032:analysis*; D006801:Humans; D008297:Male; D008567:Membranes, Artificial; D051381:Rats; D017208:Rats, Wistar
D001786:Blood Glucose; D008567:Membranes, Artificial; D002482:Cellulose; D005947:Glucose