Zwitterionic-Bias Copolymer for Selective Leukocyte Removal

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Solution Overview

Problem

Current blood cell selection materials fail to achieve selective separation of platelets, erythrocytes, and leukocytes without causing blood coagulation or allergic responses, as they lack control over zwitterionic bias and charge distribution, leading to inadequate selectivity and potential activation of platelets.

Innovation Solution

A zwitterionic-bias material is developed by controlling the distance, distribution, and ratio of charged moieties to create a specific zwitterionic-bias, allowing for selective blood cell separation without coagulation or platelet activation, using a copolymer formed by zwitterionic and charged structural units with randomly arranged positively and negatively charged moieties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a positively charged surface is used to attract leukocytes and platelets, then leukocyte removal efficiency is improved, but blood coagulation and platelet activation occur

Engineering Contradiction:
Improveleukocyte removal efficiencyVSAvoidblood coagulation and platelet activation
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the charge parameter from purely positive to zwitterionic (containing both positive and negative charges), specifically controlling the ratio of positive to negative charges to create a net positive charge with reduced magnitude. This parameter change allows the material to attract leukocytes while minimizing platelet activation and blood coagulation

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite material structure combining polyethylene terephthalate substrate with grafted charged polymer layers. This composite approach allows the base material to provide structural support while the charged polymer layer provides selective cell attraction, enabling differentiated interaction with various blood cell types

Inventive Principle:
Principle #40Composite materials

2Reliability

If a negatively charged surface is used to avoid blood coagulation, then blood compatibility is improved, but leukocyte removal efficiency decreases

Engineering Contradiction:
Improveblood compatibilityVSAvoidleukocyte removal efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent adjusts the charge density parameter by introducing zwitterionic groups with controlled ratios, creating a surface with both positive and negative charges. This allows the material to maintain blood compatibility through negative charge interactions while simultaneously achieving leukocyte removal through localized positive charge domains

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If a neutral surface is used to minimize blood response, then blood activation is reduced, but cell selectivity is lost

Engineering Contradiction:
Improveblood activationVSAvoidcell selectivity
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent creates local charge domains within the polymer structure where positive and negative charges are distributed non-uniformly. This local quality variation allows different regions of the surface to interact differently with various blood cell types, achieving both reduced overall blood activation and specific cell selectivity

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent modifies the charge distribution parameter by controlling the ratio and spatial arrangement of zwitterionic groups, creating a gradient or heterogeneous charge pattern that provides selective interaction with different blood cells while maintaining overall blood compatibility

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 zwitterionic-bias material effectively separates leukocytes from blood samples while preventing platelet activation and blood coagulation, demonstrating improved selectivity and safety in blood cell separation processes.

Implementation Method 1

the surface of such a leukocyte-removal filter medium is surface-treated to become positively charged because leukocytes and platelets are negatively charged. Thus, in addition to the sponge (porous) structure of the filter medium, the positively charged surface of the filter medium is also utilized to attract leukocytes and platelets

Methodology Applied
Scientific EffectElectrostatic attraction: Electrostatics

Data Source

PatentEP3095502B1Double-ion charge deviation-type material for blood cell screening and method for removing leukocytes from blood sample
Publication Date: 2021.01.20 CHUNG YUAN CHRISTIAN UNIVERSITY
  • EP3095502B1 patent drawingFigure 1
  • EP3095502B1 patent drawingFigure 2
  • EP3095502B1 patent drawing

AI summary

The invention provides a zwitterionic-bias material for blood cell selection and a method for removing leukocytes from a blood sample. The zwitterionic-bias material for blood cell selection is a copolymer formed by zwitterionic structural units and charged structural units wherein the zwitterionic structural unit comprises at least one positively charged moiety and one negatively charged moiety, a distance between the positively charged moiety and the negatively charged moiety is a length of 1∼5 carbon-carbon bonds, and the zwitterionic structural units and charged structural units are randomly arranged to have zwitterionic-bias.