Tissue engineering of a bioartificial pancreas: modeling the cell environment and device function

Area of Science:

• Biomedical Engineering
• Endocrinology
• Materials Science

Background:

• Cell-based implantable artificial tissues offer promising long-term treatment for endocrine diseases, notably diabetes.
• Bioartificial pancreas devices, utilizing alginate microbeads encapsulated by a poly(L-lysine) membrane, aim to immunoprotect insulin-secreting cells while allowing nutrient exchange.

Purpose of the Study:

• To develop and analyze a mechanistic model for alginate/poly(L-lysine) microbeads containing insulin-secreting cells.
• To optimize the design of artificial pancreatic devices for effective nutrient supply and rapid secretory response.

Main Methods:

• Construction and analysis of a mathematical model simulating diffusion and cellular consumption/production within microbeads.
• Measurement of effective diffusivities of compounds through the polymer matrix with entrapped cells.
• Modeling of glucose and oxygen consumption kinetics and insulin secretion.

Main Results:

• The model predicted nutrient and metabolite concentration profiles and secretory responses based on bead size and cell loading.
• Evaluated optimal bead size and cell density for adequate cell nourishment and rapid responsiveness.
• Demonstrated that cell hypersensitivity to glucose directly impacts microbead responsiveness.

Conclusions:

• Mechanistic models with accurate parameter values are crucial for optimizing artificial tissue design.
• The developed model aids in characterizing artificial tissue behavior for restoring in vivo endocrine function.
• This approach supports the advancement of bioartificial pancreas technology for diabetes management.