Cytokine Production by SaOS-2 and Mononuclear Cells Cultivated on Alginate Titanium Surfaces Doped with Calcium Phosphates

The immune response of the host tissue to the tested biomaterial predicts the success of implantation therapy success. Connective tissue cell line SaOS-2 and mononuclear cells isolated from “buffy coat” testing determines the overall immune response to the implanted biomaterial. Alginate hydrogel coatings doped with inorganic hydroxyapatite (Ti/Alg/HAP) or beta-tricalcium phosphate (Ti/Alg/TCP) nanoparticles on Titanium grade 2 were prepared. Both cell types mentioned above were used to evaluate the cytokine production when cultivated on the proposed coatings. The pristine Ti and alginate (Alg) served as control surfaces. Cytokine production was assessed by the multiplex proteomic analysis of 40 cytokines. Mononuclear cell testing revealed differences between control (Ti, Ti/Alg) and alginate hydrogel surfaces doped with calcium phosphates (Ti/Alg/TCP and Ti/Alg/HAP). Cytokine production declines from the highest found on the mononuclear cells treated by Ti/Alg/HAP through control Ti and Ti/Alg/TCP surface to control Ti/Alg surface with lowest cytokine production. Mononuclear cells produced mostly IL-6 and IL-8. No significant differences between Ti/Alg/TCP and Ti/Alg/HAP were found in cytokines produced by cell line SaOS-2. Cell line SaOS-2 produced a wide spectrum of cytokines, but the production was low, with the exception of TIMP-2. The comparison of cytokines produced by cell line SaOS-2 and mononuclear cells from “buffy coat” indicated that mononuclear cells have much better potential to show differences between the monitored materials. The immune response of mononuclear cells showed differences between tested materials, whereas SaOS-2 cells were not sufficiently sensitive. Therefore, besides SaOS-2 cells, mononuclear cells should also be considered for in vitro evaluation of overall immune response induced by the presence of an implant.