title: The chemical digestion of Ti6Al7Nb scaffolds produced by Selective Laser Melting reduces significantly ability of Pseudomonas aeruginosa to form biofilm.
abstract: In our previous work we reported the impact of hydrofluoric and nitric acid used for chemical polishing of Ti-6Al-7Nb scaffolds on decrease of the number of Staphylococcus aureus biofilm forming cells. Herein, we tested impact of the aforementioned substances on biofilm of Gram-negative microorganism, Pseudomonas aeruginosa, dangerous pathogen responsible for plethora of implant-related infections. The Ti-6Al-7Nb scaffolds were manufactured using Selective Laser Melting method. Scaffolds were subjected to chemical polishing using a mixture of nitric acid and fluoride or left intact (control group). Pseudomonal biofilm was allowed to form on scaffolds for 24 hours and was removed by mechanical vortex shaking. The number of pseudomonal cells was estimated by means of quantitative culture and Scanning Electron Microscopy. The presence of nitric acid and fluoride on scaffold surfaces was assessed by means of IR and rentgen spetorscopy. Quantitative data were analysed using the Mann-Whitney test (P ≤ 0.05). Our results indicate that application of chemical polishing correlates with significant drop of biofilm-forming pseudomonal cells on the manufactured Ti-6Al-7Nb scaffolds ( p = 0.0133, Mann-Whitney test) compared to the number of biofilm-forming cells on non-polished scaffolds. As X-ray photoelectron spectroscopy revealed the presence of fluoride and nitrogen on the surface of scaffold, we speculate that drop of biofilm forming cells may be caused by biofilm-supressing activity of these two elements.
authors.affiliation: Department of Pharmaceutical Microbiology and Parasitology, Medical University of Wrocław, Poland.
authors.forename: Adam F
authors.initials: AF
authors.lastname: Junka
authors.affiliation: Centre for Advanced Manufacturing Technologies, Wrocław University of Science and Technology, Wrocław, Poland.
authors.forename: Patrycja
authors.initials: P
authors.lastname: Szymczyk
authors.affiliation: Department of Pharmaceutical Microbiology and Parasitology, Medical University of Wrocław, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Secewicz
authors.affiliation: Centre for Advanced Manufacturing Technologies, Wrocław University of Science and Technology, Wrocław, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Pawlak
authors.affiliation: Department of Pharmaceutical Microbiology and Parasitology, Medical University of Wrocław, Poland.
authors.forename: Danuta
authors.initials: D
authors.lastname: Smutnicka
authors.affiliation: Centre for Advanced Manufacturing Technologies, Wrocław University of Science and Technology, Wrocław, Poland.
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Ziółkowski
authors.affiliation: Department of Pharmaceutical Microbiology and Parasitology, Medical University of Wrocław, Poland.
authors.forename: Marzenna
authors.initials: M
authors.lastname: Bartoszewicz
authors.affiliation: Centre for Advanced Manufacturing Technologies, Wrocław University of Science and Technology, Wrocław, Poland.
authors.forename: Edward
authors.initials: E
authors.lastname: Chlebus
mesh_terms: D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development*; D015169:Colony Count, Microbial; D005461:Fluorine / Q000032:analysis; D007834:Lasers; D008422:Materials Testing / Q000379:methods*; D009584:Nitrogen / Q000032:analysis; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D014025:Titanium / Q000494:pharmacology*
chemical_list: C070282:Ti-6Al-7Nb alloy; D005461:Fluorine; D014025:Titanium; D009584:Nitrogen