Alginate and tunicate nanocellulose composite microbeads - Preparation, characterization and cell encapsulation

Area of Science:

• Biomaterials Science
• Biomedical Engineering
• Cell Biology

Background:

• Alginate is a traditional material for cell encapsulation.
• Cellulose nanofibrils (CNF) from tunicates offer superior properties like high purity and sustainable production.
• Developing advanced biomaterials is crucial for effective cell encapsulation.

Purpose of the Study:

• To create and characterize alginate-CNF microbeads for cell encapsulation.
• To evaluate the stability and mechanical properties of these novel microbeads.
• To assess the viability of encapsulated cells within the alginate-CNF matrix.

Main Methods:

• Preparation of alginate-CNF microbeads with varying CNF fractions.
• Assessment of microbead size, dispersity, and aspect ratio.
• Evaluation of microbead stability under saline conditions using calcium and barium crosslinking.
• Measurement of Young's moduli and dextran permeability.
• Cell viability assays for MC3T3 and NHDF cells post-encapsulation.

Main Results:

• Microbead size and dispersity increased with higher CNF content.
• Calcium-crosslinked beads showed reduced stability in saline; barium crosslinking (1 mM) ensured stability.
• Young's moduli decreased with CNF incorporation, and dextran permeability slightly increased.
• High viability (83.6%) for MC3T3 cells was observed; NHDF viability improved to 72.7% after optimization.

Conclusions:

• Alginate-CNF microbeads are promising for cell encapsulation, with tunable properties.
• Barium crosslinking is essential for stable alginate-CNF microbeads in physiological conditions.
• Optimized production techniques are key to achieving high cell viability for sensitive cell types.