Systematic Investigation of Polyurethane Biomaterial Surface Roughness on Human Immune Responses in vitro

Area of Science:

• Biomaterials Science
• Immunology
• Surface Engineering

Background:

• Biomaterial surface topography significantly influences host immune responses.
• A comprehensive understanding of how specific topographies elicit pro-inflammatory or anti-inflammatory reactions is currently lacking.

Purpose of the Study:

• To systematically investigate the impact of varying surface roughness on the immune response to medical-grade polyurethane.
• To determine if polyurethane surface topography affects immune cell behavior and cytokine release.

Main Methods:

• Polyurethane specimens with roughness ranging from 0.1 to 18 µm (Ra) were fabricated using injection molding (VDI 3400 standard).
• Immune responses were assessed in three in vitro models: THP-1-derived macrophages, human peripheral blood mononuclear cells (PBMCs), and whole blood cultures.
• Cytokine release, cell morphology, and CD molecule expression were analyzed to evaluate immunological reactions.

Main Results:

• A mild immune response to polyurethane was observed across all models, but it was not correlated with surface roughness.
• No significant influence of surface roughness was found on THP-1 macrophage morphology (spreading, circularity, elongation).
• Surface roughness did not affect CD molecule expression on T cells, NK cells, or monocytes within the PBMC model.

Conclusions:

• Modifying polyurethane surface roughness within the micrometer range does not alter the pro-inflammatory immune response.
• These findings suggest that surface roughness modifications do not compromise the immunocompatibility of polyurethane.
• Polyurethane demonstrates biocompatibility, irrespective of tested surface roughness variations.