Tese_Tânia Vieira.pdf - Ubi Thesis

Table of Contents
1. Introduction .................................................................................................. 2
1.1. Bacterial infections that affect human beings ................................................... 2
1.1.1. Bacterial infections caused by biomaterials implantation ............................... 3
1.2. Nanotechnology ........................................................................................ 5
1.3. Silver Nanoparticles ................................................................................... 7
1.3.1. Applications of silver nanoparticles .......................................................... 9
1.3.2. Mechanisms of action of silver nanoparticles ............................................ 11
1.3.3. Bacterial silver nanoparticles resistance .................................................. 13
1.3.4. Toxicity of silver nanoparticles ............................................................. 14
1.3.5. Combination of silver nanoparticles with other materials ............................. 15
1.3.5.1. Dextran .................................................................................... 16
1.3.5.2. Chitosan ................................................................................... 17
1.4. Objectives ............................................................................................ 19
2. Materials and Methods ................................................................................... 21
2.1. Materials .............................................................................................. 21
2.2. Methods ............................................................................................... 21
2.2.1. Preparation of silver nanoparticles ........................................................ 21
2.2.2. Preparation of the Chitosan/Dextran nanoparticles .................................... 21
2.2.3. Preparation of the Chitosan/Dextran nanoparticles with silver ...................... 22
2.2.4. Nanoparticles Scanning Electron Microscopy Analysis .................................. 22
2.2.5. Nanoparticles Ultraviolet-Visible Spectroscopy Analysis ............................... 22
2.2.6. Nanoparticles Fourier Transform Infrared Spectroscopy Analysis .................... 23
2.2.7. Determination of antibacterial activity ................................................... 23
2.2.7.1. Minimum Inhibitory Concentration and Minimal Bactericidal Concentration . 23
2.2.8. Proliferation of cells in the presence of the produced nanoparticles ............... 24
2.2.9. Evaluation of the cytotoxic profile of the produced nanoparticles .................. 24
2.2.10. Statistical Analysis of MTS results .......................................................... 25
3. Results and Discussion ................................................................................... 27
3.1. Characterization of Particles Morphology ....................................................... 27
3.2. Nanoparticles Ultraviolet-Visible Spectroscopy Analysis ..................................... 33
3.3. Nanoparticles Fourier Transform Infrared Spectroscopy Analysis ........................... 35
3.4. Evaluation of the antibacterial activity of the produced nanoparticles ................... 39
xi