Motivation and objective Effects of pressure and precursor flow rate on the surface chemistry of the plasma-polymerized coatings Chamber Pressure (kPa) Precursor Flow rate (g/h) S (%) C (%) O (%) - - - 77.3 ± 0.8 22.7 ± 0.8 10 0.250 9.6 ± 1.2 79.5 ± 0.5 10.9 ± 1.4 15 0.250 4.3 ± 1.1 79.7 ± 1.4 16.0 ± 2.4 10 0.125 4.3 ± 1.4 77.5 ± 0.9 18.1 ± 1.9 • The optimal chamber pressure: 10 kPa • The optimal precursor flow rate: 0.25 g/h Table 1: Surface chemical composition of untreated and plasma-coated PCL nanofibers at different pressures and precursor flow rates (discharge power: 5 W and treatment time:10 min) Effects of treatment time and discharge power on the surface chemistry of the plasma-polymerized coatings and morphology of the treated fibers Discharge power (W) Treatment time (min) S (%) C (%) O (%) - - - 77.3 ± 0.8 22.7 ± 0.8 3 10 6.0 ± 2.2 75.7 ± 0.6 18.2 ± 1.9 3 15 10.9 ± 0.7 79.1 ± 0.6 10.0 ± 1.0 5 10 9.6 ± 1.2 79.5 ± 0.5 10.9 ± 1.4 5 15 10.0 ± 0.5 81.2 ± 0.9 8.8 ± 0.4 Table 2: Surface chemical composition of untreated and plasma-coated PCL nanofibers at different treatment times and dis- charge powers. Water stability of the plasma-polymerized thiol-rich coatings Treatment Power (W) Treatment Time (min) C (%) O (%) S (%) 3 10 75.4 ± 0.4 18.1 ± 1.3 6.6 ± 1.1 3 15 77.4 ± 1.4 15.1 ± 4.3 7.5 ± 2.4 5 10 77.8 ± 0.4 13.5 ± 1.7 8.7 ± 1.4 5 15 77.5 ± 1.2 15.6 ± 2.9 6.9 ± 2.7 Table 3: Surface chemical composition of plasma-coated PCL nanofibers at different treatment times and discharge powers after immersion in water at 37˚ C for 24 h The most stable coating with the highest S-content Cyto-responsive properties of the untreated and thiolated PCL nanofibers Untreated Thiolated D1 D3 D7 Figure 5: Live-dead staining images of Schwann cells cultured on untreated and plasma-coated nanofibers for 1, 3 and 7 days. Figure 6: Percentage of metabolically active Schwann cells cultured for 1, 3 and 7 days on untreated and plasma- coated PCL nanofibers (MTS analysis). Figure 3: SEM images of the thiolated PCL nanofibers after immersion in water for 24 h at 37˚ C. Figure 4: Average diameter of the thiolated PCL nanofibers before and after immersion in water for 24 h at 37˚ C (BW: before water immersion; AW: after water immersion). Figure 1: SEM images of untreated and plasma coated PCL nano- fibers at different discharge powers and treatment times. Improved cell adhesion, proliferation and viabil- ity on plasma-coated PCL nanofibers compared to untreated nanofibers Treatment time Discharge power Methodology • Reactor: dielectric barrier discharge (DBD) environmentally friendly, homogeneous coating • Studied parameters: precursor flow rate, chamber pressure, discharge power and treatment time. Conclusion Contact Pegah Zahedifar PhD researcher- Biomedical Engineering Department of Applied Physics Faculty of Engineering and Architecture - Ghent University Sint-Pietersnieuwstraat 41 - B4, B-9000 Ghent, Belgium E-mail: Pegah.Zahedifar@UGent.be Figure 2: Evolution of the nanofiber average di- ameter as a function of plasma treatment times and discharge powers. Deposition of thiol-rich coatings on nanofibrous scaffolds via atmospheric pressure DBD plasma for tissue engineering applications Pegah Zahedifar, Rouba Ghobeira, Sheida Aliakbarshirazi, Rino Morent, Nathalie De Geyter Research Unit Plasma Technology (RUPT), Department of Applied Physics, Gent University, Sint-Pietersnieuwstraat 41, B4, 9000 Gent, Belgium Pegah.Zahedifar@ugent.be • Surface S-content of plasma polymerized layer • Thickness of the plasma polymerized layer Optimal plasma process parameters: precursor flow rate: 0.25 g/h, chamber pressure: 10 kPa, discharge power: 5 W and treatment time: 10 min Surface S-content of around 10 % Stable coatings in water at 37 ˚ C for 24 h Improved Schwann cell performances Discharge power: 5 W Treatment time: 10 min