The low contact learn more angle (high wettability), presence of oxygen in the surface layer, and rough surface of the substrate are prerequisites for successful VSMC adhesion. Thus, the difference in the number of proliferated cells between annealed and relaxed samples can be attributed to the different elemental compositions of the surface layer and resulting different wettability. From Figure 4A,B, it is evident that the cell proliferation on the other samples, sputtered

for longer times, is very low. Sputtering for longer times (100 and 200 s), which leads to the formation of homogenous and continuous metal coverage, has a negative effect on cell interaction from the JNJ-26481585 price long-term point of view. The above results are illustrated on the photographs of the adhered (first day from seeding) and proliferated (seventh day from seeding) cells on the relaxed and annealed samples (Figure 5). The cells cultivated for 24 h are equally distributed on the surface. The cells on the samples that are as-sputtered for 20 s and those on subsequently annealed samples start spreading, and their adhesion increases; however, the cells on the samples sputtered for 200 s and coated completely with

silver stay small and round shaped. After 7 days from the seeding, the cells on the samples sputtered for 20 s are numerous and evenly distributed over the sample surface. The cell proliferation on the samples sputtered MRT67307 cost ADP ribosylation factor for 200 s is much worse. In the case of the as-sputtered layer, the silver forms homogenous coverage, completely shading the original polymer surface. After annealing of the thicker Ag layer, a dramatic coalescence of silver into distinctive hummock-like structures takes place, the latter being high enough to prevent a contact between polymer substrate and adhered cells. Figure 5 Photographs of adhered and proliferated VSMCs.

Photographs of VSMCs adhered (first day) and proliferated (seventh day) on Ag-coated PTFE with different deposition times (20 and 200 s) for as-sputtered and annealed samples. Conclusions The properties of silver layers sputtered on PTFE for different times and their changes under annealing were studied by different methods. The biocompatibility of the samples prepared under different conditions was examined in vitro experiments with vascular smooth muscle cells. Relations between physicochemical properties of silver layers and their biocompatibility were found. Coating with silver leads to an increase of surface wettability, which is further affected by oxidized structures adsorbed by the sample surface. With the increasing thickness of the silver layer, an increase of the oxygen concentration is also observed which is explained by high affinity of silver to oxygen and oxidized structures.