Polyelectrolyte Multilayer Coatings As a Tunable Tool to Control Inflammatory Response to Biomaterials in Vitro

Area of Science:

• Biomaterials Science
• Immunology
• Surface Chemistry

Background:

• Immune responses to medical implants affect device performance and longevity.
• Surface modification offers a strategy to control biological interactions without altering core implant function.

Purpose of the Study:

• To investigate how tailored polyelectrolyte multilayer (PEM) coatings influence immune cell behavior and inflammatory responses.
• To assess the potential of PEM coatings to mitigate adverse immune reactions to implant materials.

Main Methods:

• Fabrication of two PEM coatings (PSS/PAH) with varied wettability and surface charge by adjusting deposition conditions.
• In vitro assessment of THP-1-derived macrophage morphology and cytoskeleton formation in response to coatings.
• Evaluation of inflammatory responses using THP-1 cells and primary human immune cells on coated polymer membranes and titanium.

Main Results:

• Differing PEM surface properties modulated macrophage morphology and actin-cytoskeleton organization.
• A highly hydrophilic and negatively charged PEM coating (PEM_HH) induced a significantly milder inflammatory response compared to a moderately hydrophilic coating (PEM_MH).
• PEM_HH coatings applied to polymer membranes and titanium substantially reduced pro-inflammatory responses, validated with primary human immune cells.

Conclusions:

• Pure PEM coatings can effectively tune immune responses without incorporating additional bioactive substances.
• Surface properties like hydrophilicity and charge density are critical in dictating the inflammatory outcome.
• PEM surface modification presents a promising approach for enhancing the biocompatibility of medical implants.