Controlling fibrinogen adsorption on polyelectrolyte multilayer films by modifying self-assembly conditions

Area of Science:

• Materials Science
• Biomaterials Engineering
• Surface Chemistry

Background:

• Polyelectrolyte multilayer (PEM) films offer tunable surface properties for biomedical applications.
• Understanding protein adsorption, like fibrinogen, is crucial for designing biocompatible materials.
• Fibrinogen adsorption impacts surface thrombogenicity and subsequent biological responses.

Purpose of the Study:

• To investigate the relationship between fibrinogen adsorption and the surface properties of PEM films.
• To explore how varying deposition conditions affect PEM film characteristics and protein interactions.
• To determine how surface properties influence fibrinogen D-domain exposure and thrombogenicity.

Main Methods:

• PEM films fabricated using poly(acrylic acid) (PAA) and poly(allylamine hydrochloride) (PAH) with a polyethyleneimine (PEI) precursor.
• Surface properties characterized by ellipsometry (thickness) and contact angle (wettability).
• Fibrinogen adsorption quantified using quartz crystal microbalance with dissipation monitoring (QCM-D) and enzyme immunoassay (EIA).

Main Results:

• PEM films exhibited tunable hydrophilicity and surface charge based on deposition pH and outermost layer.
• PAH as the outermost layer resulted in less hydrophilic films with lower surface energy.
• Fibrinogen adsorption was higher on less hydrophilic, thinner, viscoelastic, hydrated, and positively charged surfaces.
• Film thickness was controllable via solution pH during deposition.

Conclusions:

• Surface properties of PEM films significantly influence fibrinogen adsorption.
• Optimizing PEM surface characteristics can modulate fibrinogen adsorption and D-domain exposure.
• Tailoring PEM films offers a strategy to enhance hemocompatibility and reduce thrombogenicity for biomaterial applications.