Negatively Charged Membrane Oligonucleotide Concentration
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Solution Overview
Problem
Conventional methods for concentrating and diafiltration of oligonucleotides, such as those using regenerated cellulose membranes, are costly, time-consuming, and result in significant product loss due to their size-based separation limitations and low throughput.
Innovation Solution
A method employing ultrafiltration or nanofiltration using membranes with a nominal molecular weight cutoff of 700 daltons to 5000 daltons, a negatively charged surface with a zeta potential of −20 mV or lower, and a water flux of 800 to 1500 ml/min/m², which effectively retains oligonucleotides and reduces salt passage, thereby improving yield and reducing material and labor costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If regenerated cellulose membranes are used for ultrafiltration and diafiltration, then oligonucleotide retention is achieved through size-based separation, but processing time becomes very long and product loss increases
Solution Approach 1:
The patent changes the surface charge parameter of the membrane from neutral (regenerated cellulose) to negatively charged (zeta potential -20 mV or lower). This parameter change enables electrostatic repulsion of negatively charged oligonucleotides, dramatically improving retention efficiency and reducing processing time by 50% or more while maintaining high product recovery
Solution Approach 2:
The patent uses composite membrane structures combining hydrophilic polymers (such as polyacrylonitrile, polyvinylidene fluoride, or polysulfone) with negatively charged surface modifications. This composite approach provides both the mechanical integrity needed for filtration and the electrostatic properties for enhanced oligonucleotide retention, resolving the contradiction between retention reliability and processing speed
2Productivity
If larger pore size membranes are used to achieve higher throughput rates, then solution throughput rate increases, but oligomer product loss increases
Solution Approach 1:
The patent changes the surface charge parameter of the membrane to negatively charged (zeta potential -20 mV or lower), which creates electrostatic repulsion forces that retain oligonucleotides even when larger pore sizes are used. This allows the membrane to achieve higher throughput rates while maintaining low product loss, as the electrostatic interaction compensates for the increased pore size
3Manufacturing precision
If regenerated cellulose membranes are used for concentration and diafiltration, then oligonucleotide purification is achieved, but material and labor costs are very high
Solution Approach 1:
The patent changes the surface charge parameter to negatively charged, which improves purification efficiency through enhanced electrostatic repulsion of oligonucleotides. This parameter change allows for faster processing times and reduced product loss, directly lowering both material and labor costs by 50% or more while maintaining high purification standards
Solution Approach 2:
The patent employs disposable filter units with integrated negatively charged membranes that can be discarded after single use. This eliminates the need for expensive, complex cleaning and sterilization procedures associated with reusable regenerated cellulose membranes, significantly reducing manufacturing costs while maintaining consistent purification quality
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 achieves a 50%-90% reduction in costs, at least 50% reduction in product loss, and a 50% reduction in cycle time, while maintaining high purity and throughput, by utilizing a membrane with a negatively charged surface and larger pore size to enhance oligonucleotide retention.
Implementation Method 1
the membrane has a negatively charged surface with a zeta potential of −20 mV or lower... to enhance oligonucleotide retention
Implementation Method 2
filtering the solution through the membrane to remove salts from the solution and obtain a retentate solution and a permeate solution, wherein the oligonucleotides are retained in the retentate solution and the removed salts are contained in the permeate solution
Implementation Method 3
diafiltering the retentate solution with a diafiltration buffer to produce a concentrated oligonucleotide solution
Data Source
AI summary
A method for concentration of oligonucleotides from a solution comprising negatively charged oligonucleotides is provided. The method includes the steps of: circulating the solution through an ultrafiltration or nanofiltration unit having a membrane, filtering the solution through the membrane to remove salts from the solution and obtain a retentate solution including the oligonucleotides and a permeate solution including the removed salts, diafiltering the retentate solution with a diafiltration buffer to produce a concentrated oligonucleotide solution, and collecting the concentrated oligonucleotide solution. The membrane has a nominal molecular weight cutoff in the range of from about 700 to about 5000 daltons, a negatively charged surface with a zeta potential of −20 mV or lower, and a water flux in the range of 800 to 1500 ml/min/m2.