Acrylonitrile Membrane Zwitterionic Coating Thrombogenicity
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Solution Overview
Problem
Current semipermeable membranes for blood treatment, such as AN69 membranes, face challenges in reducing thrombogenicity and systemic anticoagulation requirements during extracorporeal blood treatment.
Innovation Solution
The membranes are coated with a mixture of a polycationic polymer, like polyethyleneimine, and a zwitterionic compound, (2-(methacryloyl-oxy)ethyl)dimethyl(3-sulfopropyl)ammonium hydroxide, to reduce thrombogenicity and enhance the immobilization of anticoagulation agents like heparin, thereby minimizing systemic anticoagulation needs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a negatively charged semi-permeable membrane based on polyacrylonitrile is used for blood treatment, then the membrane provides effective separation and treatment of blood, but the membrane activates thrombogenicity and requires systemic anticoagulation
Solution Approach 1:
A zwitterionic compound acts as an intermediary layer on the membrane surface, creating a steric barrier that prevents direct contact between blood components and the negatively charged membrane, thereby reducing thrombogenicity while maintaining treatment effectiveness
Solution Approach 2:
The zwitterionic compound is specifically applied to the blood-contacting surface of the membrane, creating a localized modification that reduces thrombogenicity at the critical interface without altering the bulk membrane properties needed for separation
2Object-affected harmful factors
If a cationic polymer is incorporated into the membrane to reduce contact phase activation, then thrombogenicity is reduced, but the membrane requires additional materials and complex incorporation processes
Solution Approach 1:
The zwitterionic compound forms a surface coating that can be applied as a thin, disposable layer, avoiding the need for complex bulk modification of the membrane structure while achieving the desired thrombogenicity reduction
Solution Approach 2:
The membrane system becomes a composite structure combining the base polyacrylonitrile membrane with a zwitterionic surface layer, where each component performs its specific function: the base membrane provides separation and the surface layer provides anti-thrombogenic properties
3Quantity of substance
If an anticoagulation agent is bound to the membrane surface to reduce systemic anticoagulation, then systemic anticoagulation requirements are reduced, but the membrane structure becomes more complex with multiple coating layers
Solution Approach 1:
The zwitterionic compound itself provides anticoagulant properties through its molecular structure, eliminating the need for additional anticoagulation agents while maintaining the simplified single-layer coating structure
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 modified membranes exhibit reduced thrombogenicity and improved ability to immobilize anticoagulation agents, potentially allowing for heparin-free dialysis and efficient removal of uremic toxins, including middle molecules, with enhanced convective properties for extended renal replacement therapy.
Implementation Method 1
coating a mixture of the polycationic polymer and the zwitterionic compound on the outer surface of the blood-facing separating layer
Implementation Method 2
improved ability to immobilize anticoagulation agents like heparin
Implementation Method 3
coating a mixture of the polycationic polymer and the zwitterionic compound on the outer surface of the blood-facing separating layer
Implementation Method 4
enhanced convective properties for extended renal replacement therapy
Data Source
Figure 1A~1C
Figure 2A~2B
AI summary
The present disclosure relates to improved semipermeable membranes based on acrylonitrile copolymers for use in dialyzers for the extracorporeal treatment of blood in conjunction with hemodialysis, hemofiltration or hemodiafiltration. The present disclosure further relates to methods of producing such membranes.