Combining photothermal gold nanorods and antibiotics for treatment of implant-associated infections
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Program
Materials chemistry (MPMCN), MSc
Publicerad
2023
Författare
Iwarsson, Ellen
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Implant-associated infections commonly require repeated treatment and high dosages
of antibiotics. Being able to effectively treat implant-associated infections is therefore
critical for the future of medical implants as well as being able to decrease the
usage of antibiotics. This thesis therefore considers a possible alternative to decrease
the usage of antibiotics and to more effectively treat implant-associated infections
by combining photothermal gold nanorods and antibiotics to achieve a synergistic
effect. A procedure has been developed to enable evaluation of the antimicrobial
activity and synergistic effect of the combination of photothermal gold nanorods
and antibiotics by In-Vitro studies. Before performing the In-Vitro studies were
gold nanorods synthesised with dimensions enabling emission of photothermal heat
when exposed to near-infrared (NIR) light, heat which can be used for photothermal
elimination of bacteria. The gold nanorods were thereafter immobilised on glass
substrates by electrostatic interaction, mimicking a gold nanorod-functionalised implant
surface.
The gold nanorod-functionalised substrates were thereafter implemented in the In-
Vitro studies to evaluate the antimicrobial activity of the gold nanorods exposed to
NIR-light. An antimicrobial effect could be achieved when the substrates were exposed
to NIR-light covered with a thin liquid film meanwhile no antimicrobial effect
could be achieved when the substrates were exposed to NIR-light while immersed
in liquid. The antimicrobial activity of vancomycin was also evaluated by minimum
inhibitory concentration (MIC) determinations where the MIC for planktonic
bacteria and bacteria cultivated on gold nanorod-functionalised substrates were determined.
The antimicrobial effect was thereafter evaluated for the combination of
gold nanorods exposed to NIR-light and vancomycin. No synergistic effect could be
achieved for the parameters considered. No antimicrobial activity nor synergistic
effect could therefore be achieved when the gold nanorod-functionalised substrates
were irradiated immersed in liquid, with or without antibiotics. The results implicate
that more studies are required and that the interaction between the gold
nanorods and the bacteria needs to be studied in more detail.
Beskrivning
Ämne/nyckelord
Implant-associated infections , synergistic treatment , antibiotics , gold nanorods , gold nanorod-functionalised substrates , photothermal elimination , antimicrobial resistance