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.
Dulong
Jean-Luc
JL
Laboratoire de Biomecanique et Génie Biomédical, Université de Technologie de Compiègne, UMR 6600 CNRS, BP20529, 60205 Compiègne, France.
Legallais
Cécile
C
Darquy
Sylviane
S
Reach
Gérard
G
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