A novel method to immobilize bioactive substances on hydrophobic surfaces using a polymerizable cationic lipid

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Polymer Chemistry

Background:

• Hydrophobic surfaces of medical devices often require modification for improved biocompatibility.
• Existing immobilization methods may involve harsh organic solvents, potentially damaging device materials.

Purpose of the Study:

• To develop a novel, solvent-free method for immobilizing anionic bioactive substances onto hydrophobic surfaces.
• To enhance the stability and biocompatibility of modified surfaces for medical applications.

Main Methods:

• Utilized a polymerizable cationic lipid, diallyl(dioleyl)ammonium bromide (DADOA), for ionic complexation.
• Investigated spontaneous deposition of DADOA and heparin onto hydrophobic surfaces in aqueous conditions.
• Assessed surface modification via layer thickness analysis, heparin release rates, cytotoxicity, antithrombogenicity, and cell attachability.

Main Results:

• Successfully immobilized heparin and succinylated collagen (SC) on hydrophobic surfaces via ionic complexation.
• Achieved a stable, thin layer (approx. 60 nm) with low heparin release rate (0.0017 U/cm²/min).
• Demonstrated non-cytotoxicity and improved antithrombogenicity and cell attachability of the modified surfaces.

Conclusions:

• The DADOA-based method provides stable and effective immobilization of bioactive substances on hydrophobic surfaces.
• This aqueous-based technique is suitable for modifying medical devices, avoiding solvent-induced damage.
• The developed method enhances surface biocompatibility, offering potential for improved medical device performance.