Inflammatory Response to Wear Particles: Comparisons Between Zirconia and Titanium In Vitro.

Abstract

The objective of this study was to compare the inflammatory responses from peripheral blood mononuclear cells PBMCs subjected to Titanium (Ti) and/or Zirconia (Zr) particles while growing on Ti or Zr discs. In total, 240 discs were fabricated in the size of 2 mm height and 5 mm diameter. 120 discs were made of Ti (Commercially pure (CP grade 4) and 120 discs were made of Zr (3 Mol% Yttria-Stabilized Zirconia Polycrystals (3Y TZP). The PBMCs were cultured on the two-disc materials and particles with a size up to 20 μm Ti (99, 5 % Ti) and 0, 1 -2 μm Zr (3Y TZP) were added to the cultures. The concentration levels of inflammatory cytokines in culture supernatants were measured through Bioplex assay and light microscopic analysis was performed to detect cell attachment and characterize particle shape and cell-particle interaction. The inflammatory responses from PBMCs were generally higher when cells were cultured on a Ti surface compared to a Zr surface. In addition, higher cytokine levels were generally seen when cells were cultured in the presence of Ti particles compared to Zr particles in the absence of discs. However, there were only significantly increased levels for three cytokines (MCP-1, IFN-g, and TNF-a) when particles were added to the Ti discs. Higher release of NETS from neutrophils were seen in presence of Zr particles compared to Ti particles. And a lowering of cell death was seen when adding Zr particles compared to Ti particles and unstimulated control samples. Type of growth material and presence of particle affects PBMCs in vitro. Cells seeded on Ti disc and together with Ti particles generated higher levels of inflammatory cytokines compared to the Zr counterparts.