Transport phenomena and kinetics in an extravascular bioartificial pancreas

Buladi, Bora M.; Chang, Chen; Belovich, Joanne M.; Gatica, Jorge E.

doi:10.1002/aic.690420928

Cited by 16 publications

(12 citation statements)

References 36 publications

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“…In vitro diffusion was also studied by Young (18) in the case of microencapsulation in hollow fiber. Only Buladi (19) modeled a hollow fiber device implanted in the peritoneal cavity. In this complex model, glucose and insulin diffusion was radial, but the neovascularization (capillary density) and the systemic circulation were also considered.…”

Section: Glucose and Insulin Transfer Models In An Extravascular Devicementioning

confidence: 99%

Contributions of a Finite Element Model for the Geometric Optimization of an Implantable Bioartificial Pancreas

Dulong

Legallais

2002

Artificial Organs

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The extravascular implantation of islets of Langerhans immunoprotected within a permselective membrane is a promising method to treat diabetes mellitus. However, oxygen limitation due to purely diffusive solute transport was considered to provoke tissue necrosis and graft failure. We built a solute transport model based on a finite element method aiming at optimizing the hollow fiber geometry. With a low islet density, the influence of oxygen axial flux inside the fiber was underlined and a characteristic length for oxygen supply was introduced. This study allowed the conclusion that islet density must be adapted to the fiber diameter chosen for implantation.

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Section: Glucose and Insulin Transfer Models In An Extravascular Devicementioning

confidence: 99%

Contributions of a Finite Element Model for the Geometric Optimization of an Implantable Bioartificial Pancreas

Dulong

Legallais

2002

Artificial Organs

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“…While there has been considerable work on modeling insulin secretion (especially for encapsulated islets, e.g., [19][20][21][22][23]), the present model has the unique advantage that allows the coupling of both convective and diffusive transport with reactive rates for arbitrary geometries with no symmetry restrictions. Furthermore, the present model also incorporates a comprehensive approach to account not only for first-and second-phase insulin responses, but also for both the glucose-and the oxygendependence of insulin release.…”

Section: -Cellmentioning

confidence: 99%

Glucose-stimulated insulin secretion in isolated pancreatic islets: Multiphysics FEM model calculations compared to results of perifusion experiments with human islets

Buchwald¹,

Cechin²

2013

JBiSE

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Because insulin released by the β-cells of pancreatic islets is the main regulator of glucose levels, the quantitative modeling of their glucose-stimulated insulin secretion is of obvious interest not only to improve our understanding of the processes involved, but also to allow better assessment of β -cell function in diabetic patients or islet transplant recipients as well as the development of improved artificial or bioartificial pancreas devices. We have recently developed a general, local concentrations-based multiphysics computational model of insulin secretion in avascular pancreatic islets that can be used to calculate insulin secretion for arbitrary geometries of cultured, perifused, transplanted, or encapsulated islets in response to various glucose profiles. Here, experimental results obtained from two different dynamic glucose-stimulated insulin release (GSIR) perifusion studies performed by us following standard procedures are compared to those calculated by the model. Such perifusion studies allow the quantitative assessment of insulin release kinetics under fully controllable experimental conditions of varying external concentrations of glucose, oxygen, or other compounds of interest, and can provide an informative assessment of islet quality and function. The time-profile of the insulin secretion calculated by the model was in good agree- ment with the experimental results obtained with isolated human islets. Detailed spatial distributions of glucose, oxygen, and insulin were calculated and are presented to provide a quantitative visualization of various important aspects of the insulin secretion dynamics in perifused islets.

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“…Analysis of contributions of convective and diffusive transport to insulin release lead to the realization that the membrane hydraulic blood permeability of diffusion chambers is the key for maintaining proper insulin secretion. [123][124][125][126][127][128] Likewise, a comprehensive nutrient and metabolic model was designed for bT3 cell line encapsulated in microcapsules. 16 Such models could be extended for following the fate of autoantigens released from the donor tissue and cytokines generated outside the device by macrophages.…”

Section: Mechanical and Transport Properties And Engineering Of Devicmentioning

confidence: 99%

Bioartificial Pancreas: Materials, Devices, Function, and Limitations

Prokop

2001

Diabetes Technology & Therapeutics

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The term "bioartificial endocrine pancreas" (BEP) was introduced by Anthony Sun in 1980. It was in 1968, however, that Thomas Chang proposed the use of microencapsulated islets as artificial beta-cells. By applying a semipermeable membrane on the top of microcapsules, a system can be produced that is impermeable to viable islet cells and large effector molecules of the immune system, thus providing a protection for transplanted islets against rejection. Since then, the term BEP has not often appeared in papers. Instead, the term "bioartificial pancreas" (BAP) has gained widespread use. In a broader sense, BAP would include an application of suitable endocrine cells and protective polymeric vehicles, but not necessarily providing a filtration barrier of precisely defined properties (e.g., cells injected into a gel of hyaluronate).

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Transport phenomena and kinetics in an extravascular bioartificial pancreas

Cited by 16 publications

References 36 publications

Contributions of a Finite Element Model for the Geometric Optimization of an Implantable Bioartificial Pancreas

Contributions of a Finite Element Model for the Geometric Optimization of an Implantable Bioartificial Pancreas

Glucose-stimulated insulin secretion in isolated pancreatic islets: Multiphysics FEM model calculations compared to results of perifusion experiments with human islets

Bioartificial Pancreas: Materials, Devices, Function, and Limitations

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