Biofunctional surface patterns retaining activity after exposure to whole blood.

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Biomedical Engineering

Background:

• Biofunctional surfaces are critical for life science and biomedical applications.
• Current coatings exhibit high protein adsorption, reducing functional moiety activity.
• This limits their effectiveness in biological environments.

Purpose of the Study:

• To develop a robust method for creating biofunctional surfaces resistant to nonspecific protein adsorption.
• To evaluate the long-term bioactivity retention of these surfaces in whole blood.
• To demonstrate the utility of temperature-induced polyelectrolyte (TIP) grafting for surface functionalization.

Main Methods:

• Grafting of poly(l-lysine)-grafted PEG (PLL-g-PEG) with biotin and nitrilotriacetic acid (NTA) variants onto titanium using TIP grafting.
• Incubation of functionalized surfaces in whole human blood for up to 7 days.
• Fabrication of patterned surfaces using colloidal lithography and assessment of protein binding via fluorescence microscopy and ToF-SIMS.

Main Results:

• TIP-grafted surfaces showed significantly increased polymer adsorption at 80 °C compared to 20 °C.
• Surfaces achieved near-zero nonspecific protein adsorption after 7 days in whole blood.
• Patterned biotin and NTA surfaces retained bioactivity, recognizing streptavidin and calmodulin after prolonged blood incubation.

Conclusions:

• The facile TIP grafting method provides excellent bioresistance and preserves biofunctional moiety activity.
• This approach offers a promising strategy for developing advanced biomaterials for demanding applications.
• Robust biofunctional surfaces are achievable for extended use in biological fluids.