Individuelle Response humaner Blutmakrophagen auf Netzmaterialien in der Zellkultur Individual response of human blood monocytes on mesh materials in the cell culture

Background: In the clinical settings, tolerance to implanted mesh material after hernia repair varies considerably between patients. An individual inflammatory response of monocytes might be causative. The aim of this study was to examine whether the contact of monocytes to biomaterials will lead to the secretion of pro- and anti-inflammatory cytokines and if this is influenced by the biomaterial or the individual. Material and Methods: Human blood monocytes were isolated from buffy coats of 43 healthy blood donors using density gradient centrifugation. Cells were cultivated in polystyrene culture wells (4x 106 cells/well) on polypropylene polyglactine mesh (PPPM), teflon (T) and metal (VA2-steel) as well as after addition of 1 f.Ig LPS and on pure polystyrene (control, C). Supernatant was taken after 1 h and after 5 days and was analyzed for TNFa und IL-I0. using commercially available ELISA. Donors were defined as responder when concentra­ tion differences of TN Fa in culture with PPPG- mesh, teflon and metal exceeded the 90 th percentile. Results: Elevated concentrations of TN Fa und IL-I0 were detectable after 5 days in contact to biomaterials and values were not normally distributed. Regarding TNFa, the median difference (value after 1 hour subtracted from the value after 5 days) increased significantly (p < 0,0023, highest p in all tests) in wells with composite mesh, teflon, metal and LPS by (min to max) 315.24 (-73.8 to 1084.4),39.9 (- 232.9 to 952.6), 4.2 (-106.2 to 936.3) and 27.4 (- 680,3 to 926,4), respectively. In the control, median increase was zero (- 66.2 to 137.0). Regarding the materials, increase on PPPG was significantly higher than on T and metal while there was no difference between T and metal. Additionally, in the univariate analysis, the donor was an independent factor in TNFa- secretion and 3 donors were identified as responder. Conclusion: These results suggest an individual inflammatory response of human monocytes to biomaterial. This phenomenon, which is probably based on a genetic polymorphism, needs to be clarified in further clinical and experimental investigations.