Antimicrobial TiN-Ag coatings in leather insole for diabetic foot

This work reports on TiN-Ag antimicrobial coatings deposited by d.c. magnetron sputtering on leather used for insoles on the footwear industry, studies involving the antimicrobial properties of Ag-based functionalized leathers by sputtering techniques are shown. The X-ray diffraction (XRD) results suggested the presence of crystalline fcc-TiN phase for the sample without silver, and also a fcc-Ag phase in the samples containing silver. According to the Scanning Electron Microscopy (SEM) analysis, the coatings were homogeneous and dispersed Ag clusters were detected on the surface of samples with silver content above 8 at. %. The Inductively coupled plasma—optical emission spectrometry (ICP-OES) analysis showed that the ionization of silver over time depends on the morphology of the coatings. The samples did not present cytotoxicity and only samples with incorporated silver presented antibacterial and antifungal activity, highlighting the potential of the TiN-Ag insole coatings for diseases such as diabetic foot.This research was supported by by Portuguese Foundation for Science and Technology (FCT) in the framework of Strategic Funding (co-financed via UIDB/04650/2020, UIDB/04469/2020 and UIDB/00285/2020 unit). The authors also thank the financial support in the framework of HEALTHYDENT-POCI-01-0145-FEDER-030708, ATRITO-0-POCI-01-545 0145-FEDER-030446, Science DiabetICC Footwear-Development of Innovative therapeutic footwear for diabetic feet project-POCI 01-0247-FEDER-039784 and On-Surf-POCI-01-0247-FEDER-024521, co-financed via FEDER (PT2020).