*3.4. Genotoxicity Assessment*

To estimate the genotoxicity of substances released from the surface of studied implants during the 28-day incubation in PBS, the Ames assay was carried out. It was especially important to assess if silver release from TNT/AgNPs coatings could be mutagenic. This issue is associated with an increasing number of reports warning about the genotoxicity of silver nanoparticles [39,40]. The assay was performed in five genetically modified bacteria strains according to OECD guidelines TG471 (http://www.oecd.org), allowing detection of deletion, base substitution, or frameshift mutations, depending on the tester strain's engineered genotype. The number of revertant bacterial colonies corresponds to the mutagenic potential of the analyzed agents (Figure 6). None of the implant coatings demonstrated genotoxic potential in any of the bacteria strains in this assay.

**Figure 6.** Assessment of implants' genotoxicity by the Ames assay performed in five genetically modified bacteria strains: (**a**) TA98, (**b**) TA100, (**c**) TA1535, (**d**) TA1537, and (**e**) *E.coli*; to improve the readability of Ames assay results of TA98 (a), TA1535 (c), and TA1537 (d), their enlarged versions are added.
