Fabrication of low-fouling, high-loading polymeric surfaces through pH-controlled RAFT

Area of Science:

• Materials Science
• Biotechnology
• Polymer Chemistry

Background:

• Low-fouling and high-loading surfaces are critical for advanced biosensing and blood purification.
• Poly(carboxybetaine) (pCB) surfaces offer a dual-layer approach: a dense brush layer for fouling resistance and a sparse upper layer for high-density capture agent immobilization.

Purpose of the Study:

• To develop a simplified, efficient method for fabricating multi-modal, low-fouling, and high-loading pCB surfaces.
• To create pCB surfaces with enhanced capture agent immobilization and target binding capabilities.

Main Methods:

• Utilized pH-controlled surface-reversible addition-fragmentation chain-transfer (S-RAFT) polymerization.
• Achieved multi-modal polymer layers by partial polymer termination via pH-induced aminolysis of dormant chain transfer agents (CTAs).
• Avoided quenching, re-initiation, toxic metals, and light irradiation in the fabrication process.

Main Results:

• Fabricated multi-modal pCB surfaces demonstrated low protein fouling (<6.7 ng cm⁻²).
• These surfaces exhibited significantly reduced macrophage adsorption.
• Multi-modal surfaces achieved 5-fold greater capture agent immobilization and 4-fold greater target binding compared to mono-modal surfaces.

Conclusions:

• pH-controlled S-RAFT polymerization offers a streamlined approach to creating advanced pCB surfaces.
• The developed multi-modal pCB surfaces exhibit superior performance in terms of fouling resistance, loading capacity, and target binding efficiency.
• These findings have significant implications for improving biosensing and blood purification technologies.