Antibacterial activity and toxity of silver Nanosilver versus ionic silver

Transcription

1 Antibacterial activity and toxity of silver Nanosilver versus ionic silver Libor Kvítek 1 Aleš Panáček 1, Robert Prucek 1, Jana Soukupová 1, Markéta Vaníčková 1, Milan Kolář 2 and Radek Zbořil 1 1 Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacký University, Olomouc. 2 Department of Microbiology, Faculty of Medicine and Dentistry, Palacký University, Olomouc.

2 NanoSilver in commercial products Samsung s Silver Nano Technology Libor Kvítek 2

3 Managed synthesis of silver Modified Tollens process Reduction agent Ag + + 2NH 3 [Ag(NH 3 ) 2 ] + Ag 0 Size managing changing of ammonia concentration and choice of reduction substance AgNO mol dm -3 ammonia from to 0.2 mol dm -3 Reduction substance mol dm -3 (saccharides) 25 nm 200 nm 400 nm Kvítek L., Prucek R. Panáček A. et al. J Mat Chem 15 (10), , 2005 Libor Kvítek 3

4 Study of biological properties of silver NPs Silver NPs 25 nm (0,005 mol dm -3 NH 3, reduction by maltose) Antibacterial activity gram-negative and gram-positive bacteria Antifungal activity Candida spp. Cytotoxicity human fibroblasts Toxicity ciliate (P. caudatum), fruit fly (D. melanogaster), algae (S. subspicatus) TEM UV-VIS Libor Kvítek 4

5 Antibacterial activity of silver NPs First time Size dependent study of antibacterial activity of silver NPs (25 nm 50 nm) Minimum Inhibitory Concentration MIC (mg/l) Size of Ag NPs Bacteria Ionic Ag 50 nm 25 nm 35 nm 44 nm (Maltose) (Lactose) (Glucose) (Galactose ) Enterococcus faecalis CCM Staphylococcus aureus CCM Escherichia coli CCM Pseudomonas aerugin. CCM Staphylococcus epidermidis Staphylococcus epidermidis ) (methicillin-susceptible) 2) (methicillin-resistant) Panáček A., Kvítek L., Prucek R., Kolář M.: J Phys Chem B 110 (33), , 2006 Libor Kvítek 5

6 Antibacterial activity of silver NPs Second time Enhancement of antibacterial activity of silver NPs (25 nm) by their stabilization Bacteria 1) (methicillin-susceptible) 2) (methicillin-resistant) AgNO 3 Nonstabilised silver NPs MIC (mg/l) Stabilised Ag NPs SDS Tween 80 Libor Kvítek 6 PVP 360 Enterococcus faecalis CCM Staphylococcus aureus CCM Escherichia coli CCM Pseudomonas aerugin. CCM Staphylococcus epidermidis Staphylococcus epidermidis SDS sodium dodecyl sulfate Tween 80 - polyoxyethylene sorbitan monooleate PVP 360 polyvinylpyrrolidone (M.W.= ) Kvítek L., Panáček A., Soukupová J., Kolář M. et al.: J Phys Chem C, , 2008

7 Antifungal activity of silver NPs Minimum inhibitory concentrations of 25 nm sized silver NPs MIC (mg/l) Candida spp. AgNO 3 Nonstabilised silver NPs Stabilised silver NPs SDS Tween 80 PVP 360 C. albicans I C. albicans II C. parapsilois C. tropicalis Panáček A., Kolář M., Večeřová R. et al.: Biomaterials 30, , 2009 Libor Kvítek 7

8 Antifungal activity of silver NPs Comparison of antifungal activity of silver NPs with those of common antifungals Amp Amphotericine Itra Itraconazole Flu Fluconazole Vori Voriconazole Casp - Caspofungine non-stabil. SD Tween Amp Itra Flu Vori Casp Ag NPs stabilised Ag NPs Panáček A., Kolář M., Večeřová R. et al.: Biomaterials 30, , 2009 Libor Kvítek 8

9 Cytotoxicity of silver NPs (human fibroblasts) Silver NPs: LC50(24 hours) = 25 mg/l Ionic silver: LC50(24 hours) = 1 mg/l Fluorescence intensity Silver NPs Ionic silver Control ,06 0,25 0, Concentration of silver (mg/l) Panáček A., Kolář M., Večeřová R. et al.: Biomaterials 30, , 2009 Libor Kvítek 9

10 Toxicity (ecotoxicity) of silver NPs Paramecium caudatum (ciliate) Silver NPs LC50(1hour) = 39 mg/l Ionic silver 0.4 mg/l (immediate death Kvítek L., Vaníčková M., Panáček A. et al. J Phys Chem C 113, , 2009 chlorophyll a amount (mg/l) Scenedesmus sub. (algae) Silver NPs LC50 >30 mg/l of silver Ionic silver LC50 = 5 mg/l of silver 0 0, Ag concentration (mg/l) Ionic Ag Nano Ag Control Libor Kvítek 10

11 Toxicity (ecotoxicity) of silver NPs Drosophila melanogaster Acute toxicity assay to larval stages - dose dependent study, silver NPs were added into the nutrient at the concentrations from 10 mg/l to 100 mg/l - 10 mg/l of silver no acute toxic effect, slight decreasing in cuticle pigmentation - 20 mg/l of silver - LC50-60 mg/l of silver - LC100 Comparison of flies cultivated on medium without/with silver NPs Libor Kvítek 11

12 Antimicrobial activity of silver NPs in relation to their toxicity (comparison with ionic silver) NanoAg IonicAg Antibacterial activity (MIC; 24hours) Antifungal activity (MIC; 36hours) Cytotoxicity to human fibroblasts P. caudatum 1-7 mg/l 1-2 mg/l 1 mg/l 1 mg/l 25 mg/l 1 mg/l 25 mg/l 0.4 mg/l Toxicity to S. subspicatus (LC50; 48hours) >30 mg/l 5 mg/l D. melanogaster (LC50) 20 mg/l n.a. Libor Kvítek 12

13 Acknowledgement - my colleagues from NanoSilver group - Milan Kolář and Renata Večeřová Department of Microbiology, Faculty of Medicine, Palacký University - financial support from Ministry of Education and Czech Science Fondation 1M MSM MSM GACR GAP304/10/1316 Thank you for your attention Libor Kvítek 13