Recombinant albumin monolayers on latex particles

Area of Science:

• Colloid and Surface Science
• Biomaterials Science
• Protein Adsorption Studies

Background:

• Understanding protein adsorption is crucial for biomaterial development and diagnostics.
• Recombinant human serum albumin (rHSA) is a model protein for studying adsorption phenomena.
• Polystyrene latex micro-particles offer a well-defined surface for adsorption studies.

Purpose of the Study:

• To investigate the adsorption behavior of rHSA on negatively charged polystyrene latex micro-particles.
• To quantify the effect of NaCl concentration on rHSA adsorption and coverage.
• To establish a method for preparing stable, well-controlled albumin monolayers on latex particles.

Main Methods:

• Electrophoretic mobility measurements to assess particle surface charge and protein interaction.
• Depletion method combined with electrokinetic measurements and Atomic Force Microscopy (AFM) for quantitative coverage determination.
• Stability studies monitoring electrophoretic mobility and free albumin concentration over time.

Main Results:

• Albumin adsorption was found to be irreversible across the studied NaCl concentration range (10(-3) to 0.15 M) at pH 3.5.
• Maximum albumin coverage increased from 0.7 mg m(-2) at 10(-3) M NaCl to 1.3 mg m(-2) at 0.15 M NaCl.
• Increased NaCl concentration reduced electrostatic repulsion, enhancing maximum protein coverage and confirming electrostatic interactions govern adsorption.

Conclusions:

• Albumin adsorption on latex is primarily driven by electrostatic interactions, similar to colloid deposition.
• A robust procedure for preparing albumin monolayers with controlled coverage and distribution on latex particles was developed.
• The findings provide insights into protein-surface interactions relevant for biosensor and drug delivery applications.