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- ItemNon-leaching, Highly Biocompatible Nanocellulose Surfaces That Efficiently Resist Fouling by Bacteria in an Artificial Dermis Model(Washington, DC : ACS Publications, 2020) Hassan, Ghada; Forsman, Nina; Wan, Xing; Keurulainen, Leena; Bimbo, Luis M.; Stehl, Susanne; van Charante, Frits; Chrubasik, Michael; Prakash, Aruna S.; Johansson, Leena-Sisko; Mullen, Declan C.; Johnston, Blair F.; Zimmermann, Ralf; Werner, Carsten; Yli-Kauhaluoma, Jari; Coenye, Tom; Saris, Per E.J.; Österberg, Monika; Moreira, Vânia M.Bacterial biofilm infections incur massive costs on healthcare systems worldwide. Particularly worrisome are the infections associated with pressure ulcers and prosthetic, plastic, and reconstructive surgeries, where staphylococci are the major biofilm-forming pathogens. Non-leaching antimicrobial surfaces offer great promise for the design of bioactive coatings to be used in medical devices. However, the vast majority are cationic, which brings about undesirable toxicity. To circumvent this issue, we have developed antimicrobial nanocellulose films by direct functionalization of the surface with dehydroabietic acid derivatives. Our conceptually unique design generates non-leaching anionic surfaces that reduce the number of viable staphylococci in suspension, including drug-resistant Staphylococcus aureus, by an impressive 4-5 log units, upon contact. Moreover, the films clearly prevent bacterial colonization of the surface in a model mimicking the physiological environment in chronic wounds. Their activity is not hampered by high protein content, and they nurture fibroblast growth at the surface without causing significant hemolysis. In this work, we have generated nanocellulose films with indisputable antimicrobial activity demonstrated using state-of-the-art models that best depict an "in vivo scenario". Our approach is to use fully renewable polymers and find suitable alternatives to silver and cationic antimicrobials. © 2020 American Chemical Society.
- ItemCorrelation of crystal violet biofilm test results of Staphylococcus aureus clinical isolates with Raman spectroscopic read-out(Chichester [u.a.] : Wiley, 2021) Ebert, Christina; Tuchscherr, Lorena; Unger, Nancy; Pöllath, Christine; Gladigau, Frederike; Popp, Jürgen; Löffler, Bettina; Neugebauer, UteBiofilm-related infections occur quite frequently in hospital settings and require rapid diagnostic identification as they are recalcitrant to antibiotic therapy and make special treatment necessary. One of the standard microbiological in vitro tests is the crystal violet test. It indirectly determines the amount of biofilm by measuring the optical density (OD) of the crystal violet-stained biofilm matrix and cells. However, this test is quite time-consuming, as it requires bacterial cultivation up to several days. In this study, we correlate fast Raman spectroscopic read-out of clinical Staphylococcus aureus isolates from 47 patients with different disease background with their biofilm-forming characteristics. Included were low (OD < 10), medium (OD ≥ 10 and ≤20), and high (OD > 20) biofilm performers as determined by the crystal violet test. Raman spectroscopic analysis of the bacteria revealed most spectral differences between high and low biofilm performers in the fingerprint region between 750 and 1150 cm−1. Using partial least square regression (PLSR) analysis on the Raman spectra involving the three categories of biofilm formation, it was possible to obtain a slight linear correlation of the Raman spectra with the biofilm OD values. The PLSR loading coefficient highlighted spectral differences between high and low biofilm performers for Raman bands that represent nucleic acids, carbohydrates, and proteins. Our results point to a possible application of Raman spectroscopy as a fast prediction tool for biofilm formation of bacterial strains directly after isolation from the infected patient. This could help clinicians make timely and adapted therapeutic decision in future.
- ItemIn-Vitro Biofilm Removal Efficacy Using Water Jet in Combination with Cold Plasma Technology on Dental Titanium Implants(Basel : Molecular Diversity Preservation International, 2023) Matthes, Rutger; Jablonowski, Lukasz; Miebach, Lea; Pitchika, Vinay; Holtfreter, Birte; Eberhard, Christian; Seifert, Leo; Gerling, Torsten; Schlüter, Rabea; Kocher, Thomas; Bekeschus, SanderPeri-implantitis-associated inflammation can lead to bone loss and implant failure. Current decontamination measures are ineffective due to the implants’ complex geometry and rough surfaces providing niches for microbial biofilms. A modified water jet system (WaterJet) was combined with cold plasma technology (CAP) to achieve superior antimicrobial efficacy compared to cotton gauze treatment. Seven-day-old multi-species-contaminated titanium discs and implants were investigated as model systems. The efficacy of decontamination on implants was determined by rolling the implants over agar and determining colony-forming units supported by scanning electron microscopy image quantification of implant surface features. The inflammatory consequences of mono and combination treatments were investigated with peripheral blood mononuclear cell surface marker expression and chemokine and cytokine release profiles on titanium discs. In addition, titanium discs were assayed using fluorescence microscopy. Cotton gauze was inferior to WaterJet treatment according to all types of analysis. In combination with the antimicrobial effect of CAP, decontamination was improved accordingly. Mono and CAP-combined treatment on titanium surfaces alone did not unleash inflammation. Simultaneously, chemokine and cytokine release was dramatically reduced in samples that had benefited from additional antimicrobial effects through CAP. The combined treatment with WaterJet and CAP potently removed biofilm and disinfected rough titanium implant surfaces. At the same time, non-favorable rendering of the surface structure or its pro-inflammatory potential through CAP was not observed.
- ItemIn-Vitro Biofilm Removal Efficacy Using Water Jet in Combination with Cold Plasma Technology on Dental Titanium Implants(Basel : Molecular Diversity Preservation International, 2023) Matthes, Rutger; Jablonowski, Lukasz; Miebach, Lea; Pitchika, Vinay; Holtfreter, Birte; Eberhard, Christian; Seifert, Leo; Gerling, Torsten; Schlüter, Rabea; Kocher, Thomas; Bekeschus, SanderPeri-implantitis-associated inflammation can lead to bone loss and implant failure. Current decontamination measures are ineffective due to the implants’ complex geometry and rough surfaces providing niches for microbial biofilms. A modified water jet system (WaterJet) was combined with cold plasma technology (CAP) to achieve superior antimicrobial efficacy compared to cotton gauze treatment. Seven-day-old multi-species-contaminated titanium discs and implants were investigated as model systems. The efficacy of decontamination on implants was determined by rolling the implants over agar and determining colony-forming units supported by scanning electron microscopy image quantification of implant surface features. The inflammatory consequences of mono and combination treatments were investigated with peripheral blood mononuclear cell surface marker expression and chemokine and cytokine release profiles on titanium discs. In addition, titanium discs were assayed using fluorescence microscopy. Cotton gauze was inferior to WaterJet treatment according to all types of analysis. In combination with the antimicrobial effect of CAP, decontamination was improved accordingly. Mono and CAP-combined treatment on titanium surfaces alone did not unleash inflammation. Simultaneously, chemokine and cytokine release was dramatically reduced in samples that had benefited from additional antimicrobial effects through CAP. The combined treatment with WaterJet and CAP potently removed biofilm and disinfected rough titanium implant surfaces. At the same time, non-favorable rendering of the surface structure or its pro-inflammatory potential through CAP was not observed.