Subcutaneous microdialysis probe coupled with glucose biosensor for in vivo continuous monitoring

Abstract

Suuunary-Microdialysis probes have been tested to evaluate the influence of flow-rate, probe dimensions and temperature when used as sampling systems inserted subcutaneously for in viuo monitoring of glucose. The probe was coupled with a glucose biosensor obtained from a thin layer electrochemical cell generally used as detector for liquid chromatography. Glucose oxidase was immobilized on a nylon net membrane and it was placed over an acetate cellulose membrane into the cell in contact with the platinum anode.

A microdialysis technique for continuous subcutaneous glucose monitoring in diabetic patients (part 1)

“…Glucose oxidase (GOD; EC 1.1.3.4 from Aspergillus niger , 132 U/mg from Sigma) was immobilised on a nylon net according to the following procedure. A 5% GOD solution (5 ml), and a 0.25% glutaraldehyde solution (3 ml) were mixed together, spread onto a 1 cm 2 nylon supporting net and left to dry (Moscone and Mascini, 1993a,b,c). …”

“…We demonstrate how this new device is able to overcome the problem of sensitivity variation of glucose biosensors reported in the past (Moscone et al, 1992;Aussedat et al, 2000).…”

“…A glucose biosensor is coupled to a subcutaneously inserted microdialysis probe, obtained from hollow fibre, which is expressly produced and sterilised. It has already been discussed in the past the problems encountered with this approach (Moscone et al, 1992) and how to solve them with a special design of the hydrodynamic conditions of the flow system, the wall-jet cell with a glucose biosensor (Moscone and Mascini, 1993a,b,c). With this arrangement it was possible to measure glucose continuously up to 3 h both in animals and in humans.…”

Micro-flow in vivo Analysis of l-Glutamate with an On-line Enzyme Amplifier Based on Substrate Recycling

“…This method is based on the use of a microdialysis probe in combination with an immobilized enzyme reactor. A similar attempt was achieved for the on-time monitoring of glucose 9,10 and L-glutamate [11][12][13] by using a miniaturized enzyme electrode. However, the concentration of L-glutamate in the extracellular spaces of rat brain was normally at the few µmol dm -3 level, 14,15 and the permeability of L-glutamate into the microdialysis probe was about 10% at a flow rate of 2 µl min -1 when Ringer's solution was pumped as a perfusion solution into the probe.…”

Subcutaneous glucose monitoring with GlucoDay®: comparison of the results to those obtained with the Endocrine Artificial Pancreas

“…[6][7][8][9] Observations showing that changes in glucose levels in the subcutaneous tissue are similar to those in blood [6][7][8][9] opened up the way for the development of portable devices which provide continuous measurement of glucose in the subcutaneous tissue. [10][11][12][13][14] Over the last few years, this method has attracted wide clinical interest because patients with diabetes can check their metabolic status on a 24-hour basis, including rarely monitored time periods such as postprandial and nocturnal. 15,16 Τhe present study was undertaken to assess the results of glucose monitoring using the GlucoDay ® -a new portable detector of subcutaneous glucose [17][18][19] -by comparing them to those obtained by Biostator ® , an established method for continuous intravenous glucose monitoring.…”