Viral Template Plasmid Purification via Size Separation and Anion Exchange

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Solution Overview

Problem

Current methods for producing and purifying viral template plasmids and live viruses, such as PVS-RIPO, face challenges with genetic instability and require complex, time-consuming processes that are costly and inefficient, leading to low yields and purity.

Innovation Solution

A method involving the introduction of plasmid DNA into E. coli K12 strain host cells, growing them on solid media, detecting and propagating colonies with correct nucleic acid sequences, and using size separation and anion exchange chromatography to purify the viral template plasmid and live virus, without freezing steps to minimize genetic instability and reduce purification time and complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional purification methods are used for viral template plasmids and live viruses, then the purification process can remove impurities, but the process becomes complex and time-consuming with low yields

Engineering Contradiction:
ImprovepurityVSAvoidpurification process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The purification process is divided into distinct sequential steps: size separation chromatography followed by anion exchange chromatography. Each step targets specific impurities, allowing systematic purification without requiring a single complex multi-functional system. This segmentation enables moderate complexity at each stage while achieving high overall purity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The process utilizes changes in physical and chemical parameters throughout purification. Size separation exploits differences in molecular size, while anion exchange chromatography exploits differences in charge properties. These parameter-based separations enable efficient purification with well-defined process conditions, balancing complexity and effectiveness.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If traditional purification methods are used for viral template plasmids and live viruses, then the purification process can remove impurities, but the purification time increases

Engineering Contradiction:
ImprovepurityVSAvoidpurification time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

Size separation chromatography is performed as a preliminary step before anion exchange chromatography. This preliminary action removes bulk impurities and concentrates the viral template plasmid, reducing the burden on the subsequent anion exchange step and overall purification time. The sequential arrangement optimizes the efficiency of each step.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The process skips intermediate steps that are commonly used in traditional purification methods. By going directly from size separation to anion exchange chromatography without additional precipitation or filtration steps, the process reduces total time while maintaining purity through the effectiveness of the two core chromatography steps.

Inventive Principle:
Principle #21Skipping (Rushing through)

3Ease of manufacture

If freezing steps are included in the production process, then the transformed cells can be stored and handled, but genetic instability of the plasmids increases

Engineering Contradiction:
Improvecell storage and handlingVSAvoidplasmid genetic stability
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The invention extracts or removes the freezing step from the production process entirely. By eliminating the freezing operation, the process avoids the genetic instability that freezing induces in transformed cells containing viral template plasmids. This requires careful process design to maintain cell viability and plasmid stability without freezing, but successfully achieves both ease of manufacture and genetic stability.

Inventive Principle:
Principle #2Taking out (Extraction)

4Manufacturing precision

If multiple purification steps are used to achieve high purity, then the purity of the final product increases, but the number of steps and costs increase

Engineering Contradiction:
ImprovepurityVSAvoidproduction efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The purification process uses dynamic optimization by selecting two complementary chromatography methods that together achieve high purity in minimal steps. Size separation removes size-based impurities while anion exchange removes charge-based impurities. This dynamic combination of separation mechanisms achieves high purity without requiring three or more sequential steps, maintaining productivity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The process uses two different chromatography mechanisms that complement each other, effectively copying the separation function at different levels (size and charge). This dual-approach strategy achieves comprehensive purification without requiring a single complex multi-modal system, optimizing the balance between purity and step count.

Inventive Principle:
Principle #26Copying

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 enhances the yield and purity of viral template plasmids and live viruses, reducing genetic instability and the number of purification steps, resulting in faster and more cost-effective production with yields of ≥50% and improved consistency.

Implementation Method 1

separating an aqueous fluid comprising the live virus on a size separation chromatography column

Methodology Applied
Scientific EffectSize separation chromatography: Chromatography

Implementation Method 2

separating the pooled at least one positive fraction on an anion exchange chromatography column which does not significantly bind to the virus

Methodology Applied
Scientific EffectAnion exchange chromatography: Chromatography

Data Source

PatentEP3307878B1Processes for production and purification of nucleic acid-containing compositions
Publication Date: 2021.08.04 THE GOVERNMENT OF THE UNITED STATES OF AMERICA AS REPRESENTED BY THE SECRETARY DEPARTMENT OF HEALTH & HUMAN SERVICES
  • EP3307878B1 patent drawingFigure 1A
  • EP3307878B1 patent drawingFigure 1B
  • EP3307878B1 patent drawingFigure 2

AI summary

Described are improved processes for production and purification of nucleic acid-containing compositions, such as non-naturally occurring viruses, for example, recombinant polioviruses that can be employed as oncolytic agents. Some of the described improved processes relate to improved processes for producing viral DNA template. Also described are improved processes for chromatography purification of nucleic acid-containing compositions, in which the nucleic acid is quantified in chromatography fractions using a rapid detection method of the one or more nucleic acid sequences of the nucleic acid-containing composition, such as detection by real time RT-qPCR. In addition, improved processes for production and purification of oncolytic poliovirus, such as PVS-RIPO, are described. Compositions generated using these methods are also provided.