Sequential Membrane Filtration for Sterile 400 Nm Particle Recovery

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Solution Overview

Problem

Existing filtration systems struggle to achieve high yield and sterility in purifying particles with a hydrodynamic diameter of up to 400 nm, as they often retain target molecules due to similar size dimensions with contaminants like bacteria, leading to reduced yield and the need for aseptic methods.

Innovation Solution

A filtration system comprising sequentially arranged separation membrane layers with specific mean flow pore diameters and total height configurations, ensuring high sterility and yield by using porous separation membranes with controlled pore sizes and permeability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If commercially available sterile filtration systems with nominal pore diameter of 0.2 and 0.22 μm are used, then sterility is achieved (bacteria are held back), but the yield of target particles decreases strongly because both particles and bacteria are in the same size range

Engineering Contradiction:
ImprovesterilityVSAvoidyield
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The filtration system is divided into multiple sequential membrane layers, each with different pore size characteristics. The first layer has larger pores (0.4-0.6 μm) that allow target particles to pass while the second layer has smaller pores (0.2-0.22 μm) that retain bacteria, achieving both high yield and sterility through segmented filtration stages

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the filtration system have different pore size properties tailored to specific functions. The upstream membrane layer has larger pores optimized for particle transmission, while the downstream layer has smaller pores optimized for bacterial retention, with each layer having uniform pore distribution throughout its structure

Inventive Principle:
Principle #3Local 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

The system achieves a high yield of target particles (at least 50%) while maintaining sterility by effectively filtering out bacteria, as demonstrated by an LRV of at least 7.0, using membranes with controlled pore sizes and permeability.

Implementation Method 1

one or more sequentially arranged separation membrane layers each comprising a porous separation membrane; wherein each of the porous separation membranes of the one or more separation membrane layers has a mean flow pore diameter MFP

Methodology Applied
Scientific EffectPhysical separation through porous membranes: Filter (physical)

Data Source

PatentEP4653076A1Filtration system and method for sterile filtration of particles having a hydrodynamic diameter of at most 400 nm
Publication Date: 2025.11.26 SARTORIUS STEDIM BIOTECH GMBH
  • EP4653076A1 patent drawingFigure 1
  • EP4653076A1 patent drawingFigure 2
  • EP4653076A1 patent drawingFigure 3

AI summary

The present invention relates to a filtration system for sterile filtration of particles having a hydrodynamic diameter of at most 400 nm as well as a method for sterile filtration of particles having a hydrodynamic diameter of at most 400 nm, both of which achieve a high yield of target molecules and sterility.