A generalized purification step for viral particles using mannitol flocculation.

Area of Science:

• Biotechnology
• Chemical Engineering
• Virology

Background:

• Traditional vaccine manufacturing relies on costly, complex unit operations.
• There is a growing need for cost-effective, scalable purification methods for vaccine production, especially in resource-limited settings.
• Continuous manufacturing processes are desirable for increased efficiency and reduced costs.

Purpose of the Study:

• To investigate mannitol as a novel flocculant for virus purification.
• To assess the efficacy of mannitol-mediated flocculation in removing protein contaminants.
• To evaluate the scalability and applicability of this method for both enveloped and nonenveloped viruses.

Main Methods:

• Utilized mannitol as an osmolyte flocculant for viral aggregation.
• Employed microfiltration with varying pore sizes to separate flocculated viruses from contaminants.
• Quantified viral recovery rates and protein removal percentages.

Main Results:

• Achieved viral recovery ranging from 58% to 96%, dependent on virus type, filter pore size, and initial concentration.
• Demonstrated up to 80% protein removal for small, nonenveloped viruses using a 0.1 µm filter.
• Successfully applied osmolyte flocculation to both enveloped and nonenveloped viruses.

Conclusions:

• Mannitol is an effective and scalable flocculant for virus purification, applicable to diverse viral types.
• Osmolyte flocculation offers a cost-effective alternative to traditional methods, suitable for continuous manufacturing.
• This technique holds promise for improving vaccine and gene therapy product manufacturing, particularly in developing regions.