Two animal studies were conducted to (1) characterize the tissue modifying effects of the porous Dex-loaded coatings deployed on sensor surrogate implants and (2) investigate the effects of the same coatings on the in vivo performance of Medtronic MiniMed SOF-SENSORâ„¢ glucose sensors. Here we report on the in vivo performance of implanted glucose sensors coated with Dexamethasone-loaded (Dex-loaded) porous coatings employed to mediate the tissue- sensor interface. Vallejo-Heligon, Suzana G Brown, Nga L Reichert, William M Klitzman, BruceĬontinuous glucose sensors offer the promise of tight glycemic control for insulin dependent diabetics however, utilization of such systems has been hindered by issues of tissue compatibility. Porous, Dexamethasone-loaded polyurethane coatings extend performance window of implantable glucose sensors in vivo. Histochemical evidence indicates that the tissue response leads to enhanced sensor performance. The success in implementation of such a device depends on a reaction of the tissue surrounding the implant so as not to interfere with the proper functioning of the sensor. Glucose constitutes the most important future target analyte for continuous monitoring, but the basic methodology developed for glucose could be applied to several other analytes such as lactate or ascorbate. Various design considerations, including the decision to monitor the hydrogen peroxide produced in the enzymatic reaction, are discussed. When combined with a monitoring unit, this device, based on the glucose oxidase-catalyzed oxidation of glucose, reliably monitors glucose concentrations for as long as 10 days in rats. It is flexible and must be implanted subcutaneously by using a 21-gauge catheter, which is then removed. The sensor is needle-shaped, about the size of a 28-gauge needle. The development of an electrochemically based implantable sensor for glucose is described. Wilson, G S Zhang, Y Reach, G Moatti-Sirat, D Poitout, V Thévenot, D R Lemonnier, F Klein, J C Progress toward the development of an implantable sensor for glucose. In this work, a description of this sensor and the results obtained from it will be presented showing a large dynamic range of fluorescence with glucose. Use of a glycodendrimer and longer wavelength dyes has improved the sensor"s spectral change due to glucose and the overall signal to noise ratio of the sensor. However, due to the chemical constituents of the assay, multivalent binding was evident resulting in poor spectral change due to glucose within the biological range. Previous studies have shown the ability of an embedded chemical assay using Con A and dextran with shorter wavelength dyes to both sense changes in glucose and generate sufficient fluorescent emission to pass through the dermal tissue. The sensor is based on the competitive binding reaction between the protein Concanavalin A and various saccharide molecules, specifically a glycodendrimer and glucose. Cote, Gerard L.Īn implantable sensor is being created that allows measurement of blood glucose through fluorescent detection of an embedded chemical assay. Implantable fluorescence-based glucose sensor development Feasibility of the glucose sensor was verified by both in vitro and in vivo experiments. The wired implantable glucose sensor was realized by integrating a CMOS image sensor, hydrogel, UV light emitting diodes, and an optical filter on a flexible polyimide substrate. A glucose-responsive fluorescent hydrogel is used as the mediator in the measurement scheme. Feasibility of the glucose sensor was verified by both in vitro and in vivo experiments.ĬMOS image sensor-based implantable glucose sensor using glucose-responsive fluorescent hydrogelĪ CMOS image sensor-based implantable glucose sensor based on an optical-sensing scheme is proposed and experimentally verified. Tokuda, Takashi Takahashi, Masayuki Uejima, Kazuhiro Masuda, Keita Kawamura, Toshikazu Ohta, Yasumi Motoyama, Mayumi Noda, Toshihiko Sasagawa, Kiyotaka Okitsu, Teru Takeuchi, Shoji Ohta, JunĪ CMOS image sensor-based implantable glucose sensor based on an optical-sensing scheme is proposed and experimentally verified. CMOS image sensor-based implantable glucose sensor using glucose-responsive fluorescent hydrogel.
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