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Published on: January 3, 2018
Calculation of Mass Transfer and Cell-Specific Consumption Rates to Improve Cell Viability in Bioink Tissue
Axel Pössl1, David Hartzke1, Peggy Schlupp1
1Department of Life Science Engineering, Institute of Bioprocess Engineering and Pharmaceutical Technology, Technische Hochschule Mittelhessen-University of Applied Sciences, Wiesenstrasse 14, 35390 Giessen, Germany.
Biofabrication using bioprinting requires sufficient cell numbers for tissue replacement. This study found oxygen and glutamine limit nutrient supply in cell-laden constructs, restricting cell density to approximately 10^6 cells/mL.
Area of Science:
- Biotechnology
- Tissue Engineering
- Biomaterials Science
Background:
- Extrusion-based bioprinting enables cell-laden structure fabrication for regenerative medicine.
- Ensuring adequate cell viability and function in engineered tissues necessitates efficient nutrient and oxygen supply.
- Understanding mass transfer in bioinks is crucial for designing functional cell-based therapies.
Purpose of the Study:
- To investigate mass transfer rates of essential nutrients, metabolites, oxygen, and proteins within a bioink hydrogel.
- To determine the limiting nutrients for pancreatic 1.1B4 β-cells in a bioprinted construct.
- To calculate the maximum cell density supportable by a bioink hydrogel under physiological conditions.
Main Methods:
- Calculated diffusion coefficients for glucose, glutamine, lactate, ammonia, oxygen, and bovine serum albumin in a bioink hydrogel at two temperatures.
- Analyzed nutrient consumption rates of pancreatic 1.1B4 β-cells.
- Developed a model to predict cell numbers supportable by the construct based on mass transfer and consumption rates.
Main Results:
- Diffusion rates were influenced by molecular volume, particularly in polymer-rich bioinks.
- Glutamine was identified as a limiting nutrient for pancreatic 1.1B4 β-cells.
- Oxygen and glutamine were determined to be the primary limiting nutrients in the model.
- A maximum cell density of approximately 10^6 cells/mL was found suitable for blood-like conditions.
Conclusions:
- Nutrient and oxygen diffusion limitations in bioinks restrict the cell density achievable in bioprinted constructs.
- Glutamine and oxygen availability are critical factors for maintaining cell homeostasis and viability in engineered tissues.
- The findings provide a basis for optimizing bioink formulations and construct design for cell therapy applications.
