Implanting the Glucose Enzyme Electrode: Problems, Progress, and Alternative Solutions

Abstract

An implantable glucose sensor is needed before a reliable artificial pancreas can be realized. The principles and current status of one such device, the glucose enzyme electrode, is presented and discussed. While monitoring glucose this enzyme sensor consumes enough oxygen to become oxygen-limited. This problem has been solved by developing hydrophobic membranes that are more permeable to oxygen than to glucose. Two types of membranes with this property made from (1) cross-linked albumin and (2) sebacyl chloride (nylon) are described. Placing these membranes over the glucose enzyme electrode solves the problem of oxygen limitation. Furthermore, the addition of this type of membrane increases the linear response range of the electrode to glucose to include the entire clinical range of interest (0-400 mg/dl). Other problems in developing an implantable glucose sensor are discussed. Competing strategies to achieve an implantable artificial pancreas without using electronic or mechanical components are presented and evaluated.

Impact of CCL2 and CCR2 chemokine/receptor deficiencies on macrophage recruitment and continuous glucose monitoring in vivo

“…Implantable glucose sensor technology has come a long way since its first bench top implications more than three decades ago (Updike et al 1982). Consensus is now that CGM is beneficial in insulin dependent therapy irrespective of the type of diabetes and private and governmental payers are urged to expand and foster CGM implications (Fonseca et al 2016).…”

Transience in polyion complexation between nicotinamide-modified dextran and carboxymethyl dextran during enzymatic degradation of dextran

“…In our previous report, the transmittance of the solution containing NAH-Dex and CMD with the same molecular weight dropped after H 2 O 2 addition [6]. It is thought that the transmittance drop occurred through two processes.…”

“…From these perspectives, Updike et al have proposed a model of a glucose-and degradation-controlled insulin release system. In this system, glucose oxidase immobilized to degradable polymers generates hydrogen peroxide (H 2 O 2 ) in response to glucose concentration, and H 2 O 2 can degrade the polymer chain by the action of peroxidase [6]. We proposed a model for a self-regulating degradation system using its degradation products: enzymatic degradation products from a polysaccharide generate oxidants which introduce cationic charges into the polysaccharide chains, and can form a polyion complex with an anionic polysaccharide [7].…”

Modeling and Modifying Response of Biochemical Processes for Biocomputing and Biosensing Signal Processing

“…This assumption is appropriate for electrochemical designs for glucose sensing. 39,112,113 We also assume that the oxygen concentration is constant (and therefore is absorbed in a rate constant),…”