In vitro hemocompatibility of self-assembled monolayers displaying various functional groups

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Hematology

Background:

• Self-assembled monolayers (SAMs) are crucial for tuning surface properties.
• Understanding hemocompatibility is vital for medical device development.
• Specific surface chemistries influence blood-protein interactions.

Purpose of the Study:

• To investigate the hemocompatibility of alkanethiol SAMs with different terminal groups (-OH, -CH3, -COOH).
• To correlate surface properties like hydrophilicity and functional groups with blood activation pathways.
• To analyze the impact of surface chemistry on leukocyte and platelet adhesion, complement activation, and coagulation.

Main Methods:

• Fabrication of SAMs with controlled surface chemistries using alkanethiols.
• In vitro hemocompatibility testing with fresh human whole blood.
• Analysis of blood-surface interactions, including leukocyte and platelet adhesion.
• Assessment of complement activation and contact activation pathways.

Main Results:

• Leukocyte adhesion was inhibited on methyl (-CH3) surfaces and enhanced on hydroxyl (-OH) surfaces.
• Platelet adhesion showed an inverse correlation to leukocyte adhesion.
• Complement activation strongly correlated with the presence of -OH groups and leukocyte adhesion.
• Contact activation on hydrophilic surfaces correlated with acidic surface sites (-COOH).

Conclusions:

• Surface chemistry of SAMs profoundly influences hemocompatibility by modulating distinct blood activation cascades.
• -OH groups promote leukocyte adhesion and complement activation, while -CH3 groups inhibit it.
• Coagulation and platelet activation are complex, likely resulting from combined effects of contact activation and platelet adhesion mechanisms.