Biofilm Prevention on 3D Printed Surfaces for Biomedical Applications
Nurmi, Denise (2020)
Nurmi, Denise
2020
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Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:amk-2020052513302
https://urn.fi/URN:NBN:fi:amk-2020052513302
Tiivistelmä
Biofilms are complex communities of bacteria residing within an exopolysaccharide matrix that adheres to a surface, such as medical devices and implants, causing chronic infections. Due to the antibiotic resistant nature of biofilms, the use of antibiotics alone is ineffective for treating biofilm-related infections. Hydrophilicity plays an important role in surface attachment because the first step for biofilm formation is bacterial adhesion to a surface and biofilm is less likely to form on hydrophilic surfaces. In this thesis, biofilm formation inhibition of Staphylococcus aureus on 3D printed modified surfaces was investigated. Modifications included: treatment of polylactic acid and thermoplastic polyurethane filaments with polyethylene glycol and castor oil, as well as surface polishing. Samples were tested for wettability by the contact angle method and surface changes were analyzed microscopically. Wettability of treated samples increased, except for polished thermoplastic polyurethane. All samples were decontaminated before the microbiological assays were performed. Four decontamination methods were tested (immersion in 70% ethanol for 15 minutes only and combined with vortex, autoclavation and ultraviolet germicidal irradiation). Autoclaving was an efficient sterilization method; however, this process affected the surface of the samples. Ultraviolet germicidal irradiation was an optimum decontamination step. Biofilm growth inhibition was analyzed through the resazurin method. Four out of six treated samples inhibited biofilm formation at different levels. Polished thermoplastic polyurethane and polished polylactic acid samples inhibited biofilm formation by 47% (± 6) and 33% (±36), respectively. Polylactic acid-polyethylene glycol had the most significant antibiofilm property by reducing biofilm formation by 52% (±5), followed by 22% (±12) in polylactic acid-castor oil. Based on these preliminary data, polished surfaces and filaments treatment with polyethylene glycol showed promising results for biofilm inhibition.