Antisera binding onto metals immersed in human plasma in vitro

Area of Science:

• Biomaterials science
• Surface chemistry
• Immunochemistry

Background:

• Surface properties significantly influence protein adsorption, a critical factor in biomaterial biocompatibility.
• Understanding selective protein binding is essential for designing advanced medical implants and devices.

Purpose of the Study:

• To investigate the differential binding of antifibrinogen (a-fib) and anti-high-molecular-weight kininogen (a-HMWK) to various hydrophilic metal surfaces.
• To elucidate the mechanisms of protein adsorption and displacement on titanium (Ti), silicon (Si), silver (Ag), vanadium (V), gold (Au), and chromium (Cr) surfaces.

Main Methods:

• Surfaces were rendered hydrophilic using radiofrequency plasma treatment.
• Ellipsometry was employed to quantify the binding of a-fib and a-HMWK after incubation with 10% human blood plasma.
• Protein adsorption under a fluid gradient was analyzed to study displacement effects.

Main Results:

• Ti and Si surfaces selectively bound a-HMWK but not a-fib.
• Ag, V, Au, and Cr surfaces bound both a-fib and a-HMWK.
• Protein displacement was identified as a key factor for limited a-fib deposition on Ti and Si surfaces, particularly under high plasma concentrations.
• Hydrophobic surface modifications reduced the rate of a-fib displacement.

Conclusions:

• The differential binding suggests specific interactions between certain metal surfaces and plasma proteins.
• Protein displacement mechanisms play a crucial role in determining the overall protein adsorption profile on biomaterials.
• Surface chemistry and protein concentration are critical determinants of protein adsorption and subsequent biological responses.