Polyurethane surfaces modified by amphiphilic polymers: effects on protein adsorption

Area of Science:

• Materials Science
• Polymer Chemistry
• Biomedical Engineering

Background:

• Polyurethane (PUR) is widely used but can cause adverse biological responses due to protein adsorption.
• Surface modification strategies are crucial for improving the biocompatibility of PUR materials.

Purpose of the Study:

• To investigate the surface modification of PUR using amphiphilic polymers for reduced protein adsorption.
• To compare the effectiveness of different amphiphilic polymers and modification methods (adsorption vs. blending).

Main Methods:

• Three amphiphilic polymers were synthesized or selected: graft copolymers (ACRY, STY2) and a block copolymer (PE94).
• PUR surfaces were modified by polymer adsorption from aqueous solution or by blending polymers into a PUR solution followed by casting.
• Surface characterization included X-ray photoelectron spectroscopy (XPS) and contact angle measurements.
• Protein adsorption (HSA, Fg, IgG) was quantified under static and flow conditions.

Main Results:

• Amphiphilic polymers were successfully accumulated at PUR surfaces, confirmed by XPS and contact angle analysis.
• ACRY and PE94 showed poor adsorption but significant surface effects when blended into the PUR matrix.
• All modified PUR surfaces exhibited reduced blood protein adsorption compared to unmodified PUR.
• ACRY blend modified surfaces demonstrated the lowest protein adsorption among all tested conditions.

Conclusions:

• Surface modification of PUR with amphiphilic polymers, especially through blending, effectively reduces protein adsorption.
• The ACRY polymer blend offers a promising approach for developing more biocompatible polyurethane materials.
• These findings have implications for improving the performance of biomedical devices made from PUR.