Virus-Like Particle Purification via Low pH Precipitation

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Solution Overview

Problem

Existing methods for producing virus-like particles (VLPs) struggle to effectively remove infectious agents and process contaminants, such as host cell proteins and live viruses, particularly for larger biological components like VLPs, where virus filtration is not sufficient.

Innovation Solution

The method involves adjusting the pH of VLP cell lysates or production cultures to a value less than about 5, followed by removing non-VLP particulates/aggregates to generate a purified solution. This process can include additional steps like chromatographic purification using materials like cation exchange or hydroxyapatite columns, and treatment with solvents and detergents to enhance contaminant removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If virus filtration is used to remove infectious agents, then contamination is reduced, but VLPs cannot be separated from infectious agents because they are too close in size

Engineering Contradiction:

Improveinfectious agent contaminationVSAvoidseparation capability

Core Design Contradiction:

Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by adjusting pH to less than 5 to alter the physical-chemical properties of contaminants, causing host cell proteins and nucleic acids to precipitate or aggregate, enabling their removal through filtration while preserving VLPs in the clarified solution

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent extracts harmful contaminants (host cell proteins, nucleic acids, live viruses) from the VLP production culture through a multi-step process involving pH adjustment, centrifugation, and filtration, separating the desired VLPs from process contaminants

Inventive Principle:

Principle #2Taking out (Extraction)

2Ease of operation

If low speed centrifugation and filtration are used to harvest VLPs, then clarified sample is obtained, but host cell protein and live viruses are not removed

Engineering Contradiction:

Improveharvest processVSAvoidhost cell protein and virus contamination

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent changes the pH parameter to less than 5, which causes host cell proteins and nucleic acids to denature and precipitate, making them removable by filtration while leaving VLPs intact in the clarified solution

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent performs preliminary pH adjustment and contaminant precipitation before filtration, preparing the solution in advance to facilitate effective removal of host cell proteins and viruses during the harvesting process

Inventive Principle:

Principle #10Preliminary action

3Manufacturing precision

If pH is adjusted to less than 5 to remove contaminants, then VLP to contaminant ratio increases, but process complexity increases

Engineering Contradiction:

ImproveVLP purityVSAvoidpurification process

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent utilizes pH adjustment to less than 5 as a simple yet effective parameter change that causes contaminants to precipitate, enabling their removal through standard filtration equipment without requiring complex purification systems

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces complex mechanical separation systems with a chemical approach (pH adjustment) that causes contaminants to precipitate, allowing their removal through simple filtration rather than requiring sophisticated separation equipment

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach significantly increases the ratio of VLPs to residual contaminating proteins, often by at least 50% or more, while maintaining the integrity and immunogenicity of the VLPs, effectively addressing the challenges of contaminant removal in VLP production.

Implementation Method 1

adjusting the pH of the lysate, supernatant or filtrate to a pH value less than about 5 to generate a pH-adjusted solution

Methodology Applied

Scientific EffectpH adjustment:

Implementation Method 2

removing non-VLP particulates/aggregates from the pH-adjusted solution

Methodology Applied

Scientific EffectPrecipitation: Precipitation

Implementation Method 3

ion exchange chromatography

Methodology Applied

Scientific EffectIon exchange: Ion Exchange

Implementation Method 4

hydrophobic interaction chromotography

Methodology Applied

Scientific EffectHydrophobic interaction:

Implementation Method 5

hydroxyapatite chromatography

Methodology Applied

Scientific EffectHydroxyapatite chromatography:

Data Source

PatentUS12286456B2Purification of virus like particles

Publication Date: 2025.04.29 TAKEDA VACCINES INC

AI summary

Methods of purifying virus-like particles (VLPs) that are substantially free of process contaminants and infectious agents. The methods incorporate, for example, low-pH treatment during harvest and/or inactivation by a solvent and/or detergent during VLP capture.