M. Ferraris, S. Perero, M. Miola, S. Ferraris , A. Battiato, C. Manfredotti, E. Vittone, E. Vernè

1. CHEMICAL, MECHANICAL AND ANTIMICROBIAL PROPERTIES OF SPUTTERED SILVER NANOCLUSTER-SILICA COMPOSITE THIN FILMS M. Ferraris, S. Perero, M. Miola, S. Ferraris, A. Battiato, C. Manfredotti, E. Vittone, E. Vernè

2. THE PROBLEM • Medical devices • Surfaces for everyday-life • Surfaces used by hundreds of people • … Bacterial contamination

3. AIM of THE WORK • Obtain an effective and versatile antibacterial layer • Stable (thermally, chemically … ) • Applicable to different surfaces • With tailorable antibacterial activity • Broad spectrum of activity • Low resistance development • This research activity is supported by: • Regione Piemonte, Italy, with ‘‘NABLA- Nanostructured Antibacterial Layers.’’ • EU Project-NASLA-FP7-SME-2010-1 (Project 262209)

4. SILVER well known antibacterial agent broad spectrum activity Low resistance development SILICA Thermal, chemical, mechanical stability SPUTTERING Ag SILICA SILICA TARGET SILVER TARGET

5. SUBSTRATE SUBSTRATE Ar Ar SILVER NANOCLUSTERS-SILICA ANTIBACTERIAL LAYER Ag SILICA CO-SPUTTERING: THE SILVER NANOCLUSTERS-SILICA FILM

6. O 1s 532.7 eV SiO2 Secondary components  carboxylic groups from contaminations C 1s contaminants 284.47 eV CH2 285.38 eV C-O and C-CO 288.49 eV  COOH Si 2p 103.38 eV SiO2 Ag 3d 368.48 eV Ag0 METALLIC SILVER NANOCLUSTERS ! XPS CHARACTERIZATION OF THE SPUTTERED LAYER (*) (*) Experimental Physics Department /Centre of Excellence “Nanostructured Interfaces and surfaces”, University of Torino

7. MORPHOLOGICAL AND CHEMICAL CHARACTERIZATION As Dep. 150 ºC 300 ºC 450 ºC 600 ºC M. Ferraris et al., ADVANCED BIOMATERIALS, 2010, ISSN: 1868-4505. M. Ferraris et al., MATERIALS CHEMISTRY AND PHYSICS 120 (2010) 123–126.

8. ANTIBACTERIAL ACTIVITY: inibition halo S. aureus As Dep. 150 ºC 300 ºC 450 ºC 600 ºC Gamma ster. EtO ster. M. Ferraris et al., ADVANCED BIOMATERIALS, 2010, ISSN: 1868-4505. M. Ferraris et al., MATERIALS CHEMISTRY AND PHYSICS 120 (2010) 123–126.

9. 20 m 20 m 20 m 20 m 20 m MECHANICAL PROPERTIES As Dep. 150 ºC 300 ºC 450 ºC 600 ºC Tape adhesion Scratch resistance M. Ferraris et al., ADVANCED BIOMATERIALS, 2010, ISSN: 1868-4505. M. Ferraris et al., MATERIALS CHEMISTRY AND PHYSICS 120 (2010) 123–126.

10. SILVER RELEASE (*) (*) Traumatology and Work Medicine Department of C.T.O (Turin) M. Ferraris et al., ADVANCED BIOMATERIALS, 2010, ISSN: 1868-4505. M. Ferraris et al., MATERIALS CHEMISTRY AND PHYSICS 120 (2010) 123–126.

11. TAPE TEST (ASTM D 3359):good adhesion of the coating to the substrate. COATINGS ON POLYMERS FOR BIOMEDICAL APPLICATIONS • Antibacterial properties are maintained after sterilization (chemical and radiation) • The deposited film maintains its properties after the common washing procedures included in the medical devices production routes • Stability and silver release in physiological solution UNDER INVESTIGATION • Cellular tests UNDER INVESTIGATION

12. 2 3 • Antibacterial activity connected to silver content • Antibacterial activity maintained after aging 1 1 3 2 TAPE TEST (ASTM D 3359):good adhesion of the coating to the substrate COATINGS ON POLYMERS FOR AEROSPACE APPLICATIONS

13. 0 1 2 3 4 COATINGS ON MATERIALS FOR MOBILE TELEPHONES APPLICATIONS ACOUSTIC FELT SCREEN

14. MILK AGEING TAPE TEST  good adhesion ANTIBACTERIAL EFFECT COATINGS ON MATERIALS FOR FOOD INDUSTRY APPLICATIONS

15. COATINGS ON MATERIALS FOR EQUIPMENTS AND PERSONNEL PROTECTIVE SYSTEMS

16. CONCLUSIONS AND FUTURE DEVELOPMENTS • Silver nanoclusters-silica antibacterial layer has been deposited on model silica substrates and characterized after different thermal treatments • Co-sputtering deposition technique allow to vary silver content of the layer in order to obtain different antibacterial activities • The layer has been effectively deposited on different substrates from industrial partners • Particular tests are under investigation by industrial partners in order to optimize the layer for specific applications

17. Thanks!