Blood Processing Beads with Zwitterionic Polymer Coating

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Solution Overview

Problem

Conventional biocompatible polymers used in blood purification devices face a trade-off between improved biocompatibility and reduced adsorption of hydrophobic inflammatory mediators due to hydrophilicization of porous bead surfaces, and high elution of zwitterion-containing polymers into blood due to high water solubility.

Innovation Solution

Supporting a polymer with a specific monomer structure, such as 2-methoxyethyl methacrylate, on porous beads made of acrylic, styrene, or cellulose-based resins, which balances hydrophilicity and hydrophobicity to maintain adsorption while reducing polymer elution, using 10-30 mol% zwitterionic monomers to inhibit elution and 0.08-114 mg biocompatible polymer per gram of beads to prevent site blockage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional biocompatible polymers are coated on porous beads to improve biocompatibility, then blood compatibility is improved, but adsorption of hydrophobic inflammatory mediators is reduced due to hydrophilicization of surfaces

Engineering Contradiction:
ImprovebiocompatibilityVSAvoidadsorption of inflammatory mediators
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent changes the chemical composition parameters of the coating polymer by incorporating specific monomers (formula (1) with ether oxygens, formula (2) with carbonyl groups) in controlled ratios (formula (3)). This parameter optimization allows the coating to maintain appropriate hydrophobicity for adsorbing inflammatory mediators while preserving biocompatibility.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite coating material combining multiple monomer units with different functional groups (ether oxygens from formula (1), carbonyl groups from formula (2)) in a specific copolymer structure. This composite approach balances hydrophilic and hydrophobic characteristics to simultaneously achieve biocompatibility and adsorption capability.

Inventive Principle:
Principle #40Composite materials

2Reliability

If zwitterion-containing polymers are used to improve biocompatibility, then blood compatibility is enhanced, but elution of polymers into blood increases due to high water solubility

Engineering Contradiction:
ImprovebiocompatibilityVSAvoidelution of polymer into blood
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent optimizes the molecular weight and compositional parameters of the copolymer to reduce water solubility while maintaining biocompatibility. By controlling the ratio of zwitterionic monomers (10-30 mol%) and adjusting the overall polymer structure, the coating achieves low elution into blood while preserving blood compatibility.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a coating with localized distribution of zwitterionic groups rather than uniform distribution throughout the entire polymer chain. This local concentration approach maintains biocompatibility at the blood-coating interface while reducing overall water solubility and elution of the polymer into blood.

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 solution maintains high biocompatibility and adsorption efficiency of blood purification beads, reducing platelet adhesion and elution of polymers into blood, thereby enhancing the effectiveness of blood processing.

Implementation Method 1

adsorption-type blood purification devices that adsorb and remove inflammatory mediators

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 2

the adsorbents are coated with biocompatible polymers, and typically hydrophilic polymers

Methodology Applied
Scientific EffectHydrophilic interaction: Hydrophile

Data Source

PatentEP3819000B1Beads for blood processing
Publication Date: 2024.08.21 ASAHI KASEI MEDICAL CO LTD
  • EP3819000B1 patent drawingFigure 1
  • EP3819000B1 patent drawingFigure 2
  • EP3819000B1 patent drawingFigure 3

AI summary

Provided are beads for blood processing having porous beads and a polymer carried on the surface of the porous beads, wherein: the porous beads are configured from at least one resin selected from the group consisting of acrylic resins, styrene resins, and cellulose resins; and the polymer includes a specific monomer defined in the description as a monomer unit.