Mixed-Mode Chromatography for Carbohydrate-Oligonucleotide Purification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for purifying nucleic acid therapeutics, such as carbohydrate-conjugated oligonucleotides, are inadequate due to increased complexity and impurity challenges, requiring novel preparative purification techniques that conventional ion-exchange and reversed-phase chromatographic methods cannot effectively address.
Innovation Solution
The development of mixed-mode chromatography using a stationary phase with strong anion and cation exchange ligands, combined with a tailored mobile phase featuring a dual pH/salt gradient, allows for effective separation of carbohydrate-oligonucleotide conjugates from impurities by leveraging ion-exchange and hydrophobic interactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional ion-exchange or reversed-phase chromatographic methods are used, then the purification process is simple and cost-effective, but the purification selectivity and yield are insufficient for complex carbohydrate-conjugated oligonucleotides
Solution Approach 1:
The patent employs a mixed-mode stationary phase that integrates multiple functional moieties (anion-exchange, cation-exchange, and hydrophobic groups) within a single chromatography medium. This composite structure enables simultaneous exploitation of different interaction mechanisms to achieve superior separation of carbohydrate-conjugated oligonucleotides from impurities, directly resolving the contradiction between purification selectivity and method complexity.
Solution Approach 2:
The patent utilizes a dual pH/salt gradient elution strategy, dynamically adjusting both pH and ionic strength parameters during the chromatographic process. This multi-parameter control approach optimizes the interaction between the mixed-mode stationary phase and target molecules, enhancing purification selectivity while maintaining a manageable procedural framework.
2Manufacturing precision
If reversed-phase chromatography with 5′ protecting groups is used, then truncated failure sequences can be purified, but additional deprotection steps are required increasing cost and processing time
Solution Approach 1:
The patent extracts the purification function from the protecting group strategy. By using a mixed-mode stationary phase that recognizes the carbohydrate-conjugated structure itself, the method achieves purification without relying on 5′ protecting groups, thereby eliminating the need for subsequent deprotection steps and reducing overall processing time while maintaining high purity.
Solution Approach 2:
The mixed-mode stationary phase acts as an intermediary that directly interacts with the carbohydrate-conjugated oligonucleotide structure through multiple interaction modes. This intermediary mechanism enables selective retention and purification of the target molecule without requiring chemical protecting groups, streamlining the overall purification workflow.
3Reliability
If structural modifications are made to enable in vivo use, then delivery and stability are enhanced, but the complexity of molecules and impurity types increase making conventional purification inadequate
Solution Approach 1:
The patent employs a mixed-mode stationary phase that integrates multiple functional moieties (anion-exchange, cation-exchange, and hydrophobic groups) within a single chromatography medium. This composite structure enables simultaneous exploitation of different interaction mechanisms to achieve superior separation of carbohydrate-conjugated oligonucleotides from impurities, directly resolving the contradiction between purification selectivity and method complexity.
Solution Approach 2:
The patent utilizes a dual pH/salt gradient elution strategy, dynamically adjusting both pH and ionic strength parameters during the chromatographic process. This multi-parameter control approach optimizes the interaction between the mixed-mode stationary phase and target molecules, enhancing purification selectivity while maintaining a manageable procedural framework.
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 purification of carbohydrate-oligonucleotide conjugates by achieving improved selectivity and yield, effectively separating the target molecules from unconjugated oligonucleotides and other impurities, thereby addressing the limitations of conventional chromatographic methods.
Implementation Method 1
a mixed-mode stationary phase comprising strong anion exchange ligands, strong cation exchange ligands, and hydrophobic ligands
Implementation Method 2
a mixed-mode stationary phase comprising strong anion exchange ligands, strong cation exchange ligands, and hydrophobic ligands (e.g. alkyl chains)
Implementation Method 3
employing an anion-exchange matrix for purification
Data Source
AI summary
The present invention relates to methods for purifying nucleic acids. In particular, the present invention relates to methods for purifying carbohydrate-conjugated oligonucleotides using a mixed-mode stationary phase and a mobile phase comprising a dual salt/organic solvent gradient. Methods for purifying carbohydrate-conjugated oligonucleotides using an anion exchange stationary phase and a mobile phase comprising a dual pH/salt gradient are also described.