Department of Biochemistry and Molecular Biology, University of Bucharest
A major prerequisite for the long-term survival and function of biomaterials is that they do not elicit a detrimental inflammatory response upon implantation. In this context, the aim of our investigation was to compare the macrophage response to the newly developed β-type super-elastic Ti23Nb0.7Ta2Zr0.5N alloy and commercial Ti6Al4V exhibiting similar surface topographic features. Specifically, in vitro behavior of RAW 264.1 cells in contact with both surfaces was analyzed with respect to cell attachment, morphology and cytoskeleton organization, cell viability/proliferation and gene expression/protein secretion profiles of proinflammatory mediators (TNF-a, IL-1b, IL-6, MCP-1, MIP-1a and RANTES). Both samples sustained cellular viability and promoted cell proliferation to an almost identical extent. Besides, no significant differences in cell morphology and distribution of cytoskeletal components were remarked. In regards to the release of proinflammatory mediators, macrophages responded to both alloy surfaces in an identical manner, possibly due to similar topography. However, lower cytokine mRNA expression levels were noticed following cell exposure to Ti23Nb0.7Ta2Zr0.5N when compared to Ti6Al4V, suggesting that this novel alloy induces a decrease in the proinflammatory macrophage genotype. Furthermore, a marked decrease in the amount of secreted cytokines and gene expression profiles at 48h post-seeding suggests that the analyzed surfaces facilitate wound healing.
Keywords: beta-titanium alloy, macrophage, biocompatibility, proinflammatory cytokines and chemokines.