Encapsulation of yeast cells in colloidosomes

Area of Science:

• Biomaterials Engineering
• Colloid Science
• Microencapsulation Technology

Background:

• Colloidosomes offer a versatile platform for microencapsulation.
• Encapsulating viable cells presents challenges in maintaining metabolic activity.
• Controlling diffusion through capsule shells is crucial for controlled release and cellular function.

Purpose of the Study:

• To prepare and characterize polymeric colloidosomes encapsulating viable Baker's yeast.
• To assess the metabolic activity of encapsulated yeast cells.
• To investigate the impact of shell structure on diffusion limitations.

Main Methods:

• Preparation of colloidosomes via emulsion of latex particles and yeast in oil, followed by ethanol-induced aggregation.
• Characterization using optical, confocal, and scanning electron microscopy.
• Assessment of yeast viability and metabolic activity using fluorescent probes and glucose metabolism assays.

Main Results:

• Successfully fabricated polymeric colloidosomes encapsulating viable Baker's yeast.
• Encapsulated yeast exhibited glucose metabolism, albeit at a reduced rate compared to free yeast, indicating diffusion limitation.
• Demonstrated that a double latex shell design enhances diffusive resistance.

Conclusions:

• Polymeric colloidosomes can successfully encapsulate viable Baker's yeast.
• The colloidosome shell imposes diffusion limitations on nutrient uptake and waste removal.
• Shell architecture, such as a double layer, can be tuned to control diffusive properties for enhanced cellular encapsulation applications.