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In Vitro Evaluation of a Bioartificial Pancreas Under Various Hemodynamic Conditions
Author(s) -
Moussy Francis,
Rouchette Jeanne,
Reach Gérard,
Can Robert,
Jaffrin Michel Y.
Publication year - 1989
Publication title -
artificial organs
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.684
H-Index - 76
eISSN - 1525-1594
pISSN - 0160-564X
DOI - 10.1111/j.1525-1594.1989.tb02845.x
Subject(s) - insulin , artificial pancreas , islet , chemistry , polyacrylonitrile , blood flow , biomedical engineering , materials science , chromatography , medicine , endocrinology , diabetes mellitus , type 1 diabetes , polymer , organic chemistry
A bioartificial pancreas in which isolated islets of Langerhans are placed between two polyacrylonitrile membranes, blood circulating successively above the upper and below the lower membranes following a U‐shaped circuit, has been developed. The two parts are connected by an outer loop consisting of a thin tubing. The length of this tubing determines the magnitude of the flow rate of blood through the device. The aim of this work was to determine experimentally the optimal configuration of the system containing isolated rat islets and a Krebs buffer circulating through the device. The amount of insulin released by the bioartificial pancreas was determined during a 20‐mM square‐wave glucose stimulation. First, the inlet pressure was set at 100 mm Hg, and the effect of the length of the tubing was investigated with two devices perfused simultaneously. For a short tubing (flow rate, 20 ml/min), a sharp increase in insulin release in response to glucose was observed; it increased within 4 min from 217±50 to 761±237 μ U/500 islets/min (p<0.05), the peak value being reached at 11±2 min following the beginning of the stimulation. For a long tubing (flow rate, 3 ml/min), the increase in insulin release was more sluggish. It increased from 133±53 to 222±43 μ U/500 islets/min at 4 min, the peak value being reached only at 20±3 min. These data are consistent with a more efficient diffusional transfer of insulin in the case of the high circulating flow. In a second series of experiments, the two chambers were perfused simultaneously at the same flow rate, set by a peristaltic pump (3 ml/min). Here, the kinetics of insulin release were slightly but not significantly faster when the chamber was set up with a long connector, producing a larger contribution of ultrafiltration to the transfer of glucose and insulin across the membranes. Therefore, a short connector yields better glucose‐insulin kinetics when the device works at a set inlet pressure that might mimic the condititons of in vivo implantation. Furthermore, this design should be less thrombogenic.