Bactericidal behaviour of Ti6Al4V surfaces after exposure to UV-C light.

Departamento de Física Aplicada, Facultad de Ciencias, Universidad de Extremadura, Avda de Elvas s/n, 06071 Badajoz, Spain.
Biomaterials (Impact Factor: 8.31). 04/2010; 31(19):5159-68. DOI: 10.1016/j.biomaterials.2010.03.005
Source: PubMed

ABSTRACT TiO(2)-coated biomaterials that have been excited with UV irradiation have demonstrated biocidal properties in environmental applications, including drinking water decontamination. However, this procedure has not been successfully applied towards the killing of pathogens on medical titanium-based implants, mainly because of practical concerns related to irradiating the inserted biomaterial in situ. Previous researchers assumed that the photocatalysis on the TiO(2) surface during UV application causes the bactericidal effects. However, we show that a residual post-irradiation bactericidal effect exists on the surface of Ti6Al4V, not related with photocatalysis. Using a combination of staining, serial dilutions, and a biofilm assay, we show a significant and time-dependent loss in viability of different bacterial strains of Staphylococcus epidermidis and Staphylococcus aureus on the post-irradiated surface. Although the duration of this antimicrobial effect depends on the strains selected, our experiments suggest that the effect lasts at least 60 min after surface irradiation. The origin of such phenomena is discussed in terms of the physical properties of the irradiated surfaces, which include the emission of energy and changes in surfaces charge occurring during electron-hole recombination processes. The method here proposed for the preparation of antimicrobial titanium surfaces could become especially useful in total implant surgery for which the antimicrobial challenge is mainly during or shortly after surgery.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Dental and orthopaedic implants have been under continuous advancement to improve their interactions with bone and ensure a successful outcome for patients. Surface characteristics such as surface topography and surface chemistry can serve as design tools to enhance the biological response around the implant, with in vitro, in vivo and clinical studies confirming their effects. However, the comprehensive design of implants to promote early and long-term osseointegration requires a better understanding of the role of surface wettability and the mechanisms by which it affects the surrounding biological environment. This review provides a general overview of the available information about the contact angle values of experimental and of marketed implant surfaces, some of the techniques used to modify surface wettability of implants, and results from in vitro and clinical studies. We aim to expand the current understanding on the role of wettability of metallic implants at their interface with blood and the biological milieu, as well as with bacteria, and hard and soft tissues.
    Acta biomaterialia 04/2014; DOI:10.1016/j.actbio.2014.03.032 · 5.68 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A simple method for the green synthesis of silver nanoparticles (AgNPs) using autoclave assisted gum extract of neem (Azadirachta indica) has been investigated for the first time. Silver nanoparticles were formed due to reduction of silver nitrate solution when mixed with the gum extract after autoclaving at 121 ◦C and 15 psi. The UV–vis absorption spectrum of the biologically reduced reaction mixture showed the surface plasmon peak at 418 nm which is characteristic peak of silver nanoparticles. The functional biomolecules present in the gum extract and the interaction between the nanoparticles were identified by the Fourier transform infrared spectroscopy (FTIR) analysis. Average diameter of the synthesized nanoparticles was found to be <30 nm, as revealed from transmission electron microscopy (TEM) and atomic force microscopy (AFM) analysis. X-ray diffraction (XRD) analysis confirmed the face-centered cubic crystalline structure of metallic silver. The synthesized silver nanoparticles exhibited antibacterial activity against clinical isolates of Salmonella enteritidis and Bacillus cereus. Moreover, the antibacterial activity ofthe silver nanoparticles was further confirmed by degradation oftest bacterial DNA. The results suggestthatthe gum mediated synthesized silver nanoparticles could be used as a promising antibacterial agent against clinical pathogens.
    Industrial Crops and Products 04/2015; 66:103–109. DOI:10.1016/j.indcrop.2014.12.042 · 3.21 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The choice of material for implanted prostheses is of great importance concerning bacterial colonization and biofilm formation. Consequently, methods to investigate bacterial behavior are needed in order to develop new infection resistant surfaces. In this study, different methodological setups were used to evaluate the antimicrobial effect of photocatalytic titanium oxide and silver surfaces. Biofilm formation and eradication under static and dynamic culture conditions were studied with the use of the following analytical techniques: viable colony-forming unit (CFU) counting, imprinting, fluorescence, and bioluminescence. The present study demonstrates that different methods are needed in order to evaluate the prophylactic and treatment effects on planktonic and biofilm bacteria and to assess the antimicrobial effect of different surface treatments/coatings. Choosing the right antibacterial testing model for the specific application is also of great importance. Both in situ approaches and indirect methods provide valuable complementary information. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2014.
    Journal of Biomedical Materials Research Part B Applied Biomaterials 05/2014; DOI:10.1002/jbm.b.33179 · 2.33 Impact Factor