Antibacterial Surfaces to Prevent Biofilm Formation on Cementless Bone Implants

Antibacterial Surfaces to Prevent Biofilm Formation on Cementless Bone Implants

Gudmundsson, K.

Apachitei, J. (mentor)

Mechanical, Maritime and Materials Engineering

BioMechanical Engineering

BME

2014-09-16

Despite preventive measures in hospitals through the control of environmental and personnel contamination and systemic administration of antibiotics, implant associated infections (IAIs) still remain a serious ongoing problem for hospitals and patients around the world. The main characteristic of IAIs is that bacteria colonizes the implants surface and forms hard to treat biofilm, which can lead to implant loosening and require expensive and often traumatic revision surgery. The demand for improved antibacterial technologies has never been higher with the rising usage of implants worldwide and the ever increasing bacterial resistance against modern day antibiotics. Currently, there are no clinical proven local antibacterial delivery options available for cementless bone implants. The aim of the master's thesis was the synthesis, characterization, in vitro and ex vivo antibacterial evaluation of the porous oxidized silver-bearing surfaces on titanium mouse implants. The synthesis of the antibacterial surfaces was performed on commercially pure (CP) titanium through a surface modification treatment, called plasma electrolytic oxidation (PEO), in an aqueous electrolyte based on calcium acetate/calcium glycerophosphate bearing various concentrations of Ag nanoparticles. The characterization of the antibacterial surfaces involved surface morphology, chemical analyses and phase composition, performed by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The in vitro and ex vivo evaluation of the antibacterial activity of the TiO2-Ag surfaces was carried out against methicillin-resistant Staphylococcus aureus (MRSA) and S. aureus GFP (green fluorescent protein). The SEM micrographs and EDS analyses of the antibacterial layers revealed a porous interconnected TiO2 structure rich in Ag, Ca and P elements. Furthermore, the XRD patterns showed the presence of the biocompatible TiO2 surfaces composed of anatase and rutile phases. The TiO2-Ag layers demonstrated promising antibacterial activity against MRSA in vitro and against S. aureus GFP in ex vivo when in direct contact with the bacteria.

silver nanoparticles
plasma electrolytic oxidation
antibacterial surfaces
implant associated infections
cementless implants
MRSA

http://resolver.tudelft.nl/uuid:5c08286a-08e0-470a-92e0-00048f61e3dd

2016-09-16

Student theses

master thesis

(c) 2014 Gudmundsson, K.