Titanium surface characteristics, including topography and wettability, alter macrophage activation

Area of Science:

• Biomaterials Science
• Immunology
• Surface Chemistry

Background:

• Titanium (Ti) implants are widely used in orthopedics and dentistry.
• Surface properties like chemistry, topography, and wettability influence cell responses.
• The impact of implant surface properties on immune cells, particularly macrophages, is not well understood.

Purpose of the Study:

• To investigate how surface modifications on titanium affect macrophage activation.
• To determine the influence of surface roughness and wettability on cytokine production by macrophages.

Main Methods:

• Macrophages were cultured on seven different titanium surfaces with varying roughness and wettability.
• Surface chemistries included smooth, microrough, and nano- and micro-rough titanium.
• Cytokine production (IL-1β, IL-6, TNFα, IL-4, IL-10) was measured to assess macrophage activation states (M1-like vs. M2-like).

Main Results:

• Smooth titanium surfaces induced an inflammatory (M1-like) macrophage response, with increased IL-1β, IL-6, and TNFα.
• Hydrophilic, rough titanium surfaces promoted an anti-inflammatory (M2-like) response, indicated by elevated IL-4 and IL-10 levels.
• Surface wettability and roughness significantly altered macrophage activation and cytokine profiles.

Conclusions:

• Macrophage activation is sensitive to biomaterial surface properties, specifically wettability and roughness.
• Hydrophilic and rough titanium surfaces can induce an anti-inflammatory microenvironment.
• Tailoring biomaterial surface properties may be a strategy to control the immune response and enhance implant integration and healing.