Amphiphilic Coated Leukocyte Filter Medium

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Solution Overview

Problem

Current filters for removing leukocytes from biological fluids, such as blood, are inefficient in terms of leukocyte removal and interaction with the filter medium, requiring improved wetting capabilities and attraction mechanisms to enhance filtration efficiency.

Innovation Solution

A polymeric composition coating on the filter medium with non-polar and polar or ionic segments is applied to enhance the filter's wetting properties and leukocyte interaction, comprising block copolymers like poly(ethylene-co-vinyl acetate) or poly(ethylene-co-acrylic acid), which is biocompatible and resistant to sterilization methods.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional filter medium is used, then the filter structure is simple, but the wetting capability is insufficient and leukocyte removal efficiency is low

Engineering Contradiction:
Improveleukocyte removal efficiencyVSAvoidfilter structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The filter medium is constructed as a composite material system combining a porous base material (such as polypropylene) with a surface coating layer containing amphiphilic polymeric composition. This composite structure integrates the mechanical support function of the porous material with the wetting and leukocyte interaction enhancement provided by the polymeric coating, thereby improving leukocyte removal efficiency without fundamentally complicating the overall filter structure.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The surface properties of the filter medium are modified by changing the chemical composition and surface energy parameters through the application of amphiphilic polymeric coating. This coating alters the wettability and surface chemistry parameters of the filter, enhancing its ability to interact with and remove leukocytes while maintaining the structural integrity of the original filter medium.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the filter medium porosity is increased to improve fluid flow, then fluid flow improves, but leukocyte retention capability decreases

Engineering Contradiction:
Improvefluid flow rateVSAvoidleukocyte retention capability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The filter medium exhibits different functional properties at different locations: the bulk interior maintains high porosity for efficient fluid flow, while the surface layer (coating) provides enhanced leukocyte interaction and retention. This local differentiation of properties allows the filter to simultaneously achieve high productivity and reliable leukocyte retention without compromising either function.

Inventive Principle:
Principle #3Local quality

3Stability of the object's composition

If the filter medium surface is made more hydrophobic to improve structural stability, then structural stability improves, but fluid wetting and flow capability deteriorates

Engineering Contradiction:
Improvefilter medium stabilityVSAvoidfluid flow capability
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

The surface energy and wettability parameters of the filter medium are modified by applying an amphiphilic polymeric coating that contains both hydrophobic and hydrophilic segments. This coating transforms the surface properties to achieve optimal wetting capability while the underlying stable porous structure maintains structural integrity, resolving the contradiction between stability and flow capability.

Inventive Principle:
Principle #35Parameter changes

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 coated filter medium effectively reduces leukocyte passage while maintaining porosity, achieving high leukoreduction and platelet recovery rates, even with aged blood, by improving fluid flow and leukocyte attraction.

Implementation Method 1

The coating is a polymeric composition having a molecular chain that includes segments of non-polar groups and segments of at least one of polar groups or segments of ionic groups... enhances the wetting capability of the filter

Methodology Applied
Scientific EffectWetting: Wetting

Implementation Method 2

segments of at least one of polar groups or segments of ionic groups... enhances... the interaction of the filter with leukocytes

Methodology Applied
Scientific EffectElectrostatic attraction: Ion Repulsion/Attraction

Data Source

PatentEP2818189B1A leukocyte reduction filter medium and method for making it
Publication Date: 2021.09.01 FENWAL INC
  • EP2818189B1 patent drawingFigure 1~2
  • EP2818189B1 patent drawingFigure 3

AI summary

Filter media, filter devices and methods of making filter media are disclosed. The filter media includes a coating on at least a portion of said outer surface. The coating may be polymeric composition having a molecular chain that includes segments of nonpolar groups and segments of at least one of polar groups or segments of ionic groups.