A novel model of solute transport in a hollow-fiber bioartificial pancreas based on a finite element method.
Extravascular bioartificial pancreas based on hollow fiber seems to be a promising treatment of diabetes mellitus. However, solutes mass-transport limitations in such a device could explain its lack of success. To determine critical device parameters, we have developed a novel tridimensional model based on finite element method for glucose, insulin, and oxygen diffusion around an islet of Langerhans encapsulated in a hollow-fiber section. A glucose ramp stimulation was applied outside the fiber and diffused to the islet. Concomitantly, a stationary oxygen partial pressure was applied outside the fiber, and determined local oxygen partial pressure on the islet environment. An insulin secretion model stimulated by a glucose concentration ramp and corrected by the local oxygen partial pressure was also implemented. Insulin secretion by the islet was thus computed as a response to glucose signal. The model predictions notably showed that the fiber radius had to be small enough to favor a fast response for insulin secretion and to ensure a maximal oxygen partial pressure in the islet environment. Besides the effect of fiber radius, a better islet oxygenation could be achieved by adjustments on the islet density, i.e., on the fiber length dedicated to a single islet. These hints should allow the future proposal of an optimal design for an implantable bioartificial pancreas.
Laboratoire de Biomecanique et Génie Biomédical, Université de Technologie de Compiègne, UMR 6600 CNRS, BP20529, 60205 Compiègne, France.
Jean-Luc
JL
Dulong
Cécile
C
Legallais
Sylviane
S
Darquy
Gérard
G
Reach
D001693:Biological Transport, Active; D003198:Computer Simulation; D020342:Finite Element Analysis; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D016381:Islets of Langerhans Transplantation / Q000295:instrumentation / Q000379:methods*; D008954:Models, Biological; D010100:Oxygen / Q000378:metabolism*; D019397:Pancreas, Artificial
D007328:Insulin; D005947:Glucose; D010100:Oxygen