Albumin adsorption on CoCrMo alloy surfaces

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Corrosion Engineering

Background:

• Proteins adsorb onto artificial joint surfaces post-implantation.
• Understanding protein adsorption mechanisms is crucial for material biocompatibility and longevity.
• Micro-level in situ observation of protein adsorption affecting CoCrMo alloy corrosion is lacking.

Purpose of the Study:

• To investigate the in situ adsorption of bovine serum albumin (BSA) on CoCrMo alloy surfaces.
• To elucidate the influence of pH and surface charge on BSA adsorption.
• To understand how BSA adsorption affects the corrosion behavior of CoCrMo alloys.

Main Methods:

• Atomic Force Microscopy (AFM) for surface topography and interaction analysis.
• Scanning Kelvin Probe Force Microscopy (SKPFM) for surface potential mapping.
• In situ observation of BSA adsorption on CoCrMo alloy under varying pH and surface charge conditions.

Main Results:

• Hydrophobic interactions govern BSA adsorption on uncharged CoCrMo surfaces, forming side-on monolayers.
• Adsorbed BSA promotes the corrosion of CoCrMo alloys.
• Electrostatic interactions dominate BSA adsorption on positively charged surfaces.
• Maximum BSA adsorption occurs at its isoelectric point (pH 4.7).

Conclusions:

• BSA adsorption mechanisms on CoCrMo alloys are pH and surface charge-dependent.
• BSA adsorption can accelerate CoCrMo alloy corrosion, impacting implant performance.
• In situ AFM and SKPFM provide critical micro-level insights into protein-surface interactions and corrosion.