Effects of Ag/TiO2 nanoparticles developed for leather surface finishing on human keratinocytes cells

Introduction. The finishing of leather surface with nanomaterials (NMs) having advanced properties (e.g. antimicrobial, self-cleaning and flame retardant) are priorities for the European leather industry. The impact of NMs on... [ view full abstract ]

Introduction. The finishing of leather surface with nanomaterials (NMs) having advanced properties (e.g. antimicrobial, self-cleaning and flame retardant) are priorities for the European leather industry. The impact of NMs on human health is very important for their large scale application in footwear industry. The aim of our study was the investigation of the effects of Ag/TiO2 nanoparticles (NPs) on human skin cells. Materials and Methods. Three formulations of Ag/TiO2 nanoparticles (NPs) were prepared using an electrochemical method for deposition of 0.53% (Ag/TiO2-NP1), 1.14% (Ag/TiO2-NP2) and 1.62% (Ag/N-TiO2-NP3), respectively of Ag on nanosized TiO2 and N-TiO2. The Ag/TiO2 and Ag/N-TiO2 NPs were characterized for i) particle size and Zeta potential (by DLS); ii) powder morphology and elements identification on surface (by SEM, EDX), iii) photocatalytic activity using the method of dye degradation under UV/Vis light. The cytotoxicity studies were performed by MTT assay after exposing human keratinocytes (HaCaT cells) to various concentrations of different Ag/TiO2 NPs (0.01-1mg/ml) for 48 hours. The organization of actin cytoskeleton was visualized by fluorescence microscopy after incubation of cells with Ag/TiO2 NPs, by staining the cells with fluorescently-labeled Phalloidin. The intracellular reactive oxygen species (ROS) levels were quantified using the fluorogenic dye 2',7'‐dichlorofluorescein diacetate, using a spectrophotometer. Results. 1) the size and Zeta potential for all three formulations was below 90 nm and above -40 mV, respectively; 2) low cytotoxic effect at concentration up to 0.3 mg/ml; 3) IC50 values (concentration of NPs where 50 % of cells are viable) are 0.75 mg/ml, 0.35 mg/ml and 0.81 mg/ml for NP1, NP2 and NP3, respectively; 4) the actin cytoskeleton in HaCaT cells is only slightly modified by exposure to Ag/TiO2 NPs at concentrations up to 0.5 mg/ml, whereas the higher concentrations of Ag/TiO2 NPs (0.5 and 1 mg/ml) induce cell retraction; 5) an increase in intracellular ROS is seen only for cells incubated with 1 mg/ml Ag/TiO2 NPs. Conclusions. The developed Ag/TiO2 NPs have a potential toxic effect at the skin level only at very high concentrations (above 0.5 mg/ml). Acknowledgement. The works were funded by UEFISCDI, project number PNIII_15/2015 under the frame of ERA-NET SIINN program.