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Ivanova EP, Nguyen SH, Guo Y, Baulin VA, Webb HK, Truong VK, Wandiyanto JV, Garvey CJ, Mahon PJ, Mainwaring DE, Crawford RJ. Bactericidal activity of self-assembled palmitic and stearic fatty acid crystals on highly ordered pyrolytic graphite. Acta Biomater 2017; 59:148-157. [PMID: 28688988 DOI: 10.1016/j.actbio.2017.07.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 07/03/2017] [Accepted: 07/03/2017] [Indexed: 11/27/2022]
Abstract
The wings of insects such as cicadas and dragonflies have been found to possess nanostructure arrays that are assembled from fatty acids. These arrays can physically interact with the bacterial cell membranes, leading to the death of the cell. Such mechanobactericidal surfaces are of significant interest, as they can kill bacteria without the need for antibacterial chemicals. Here, we report on the bactericidal effect of two of the main lipid components of the insect wing epicuticle, palmitic (C16) and stearic (C18) fatty acids. Films of these fatty acids were re-crystallised on the surface of highly ordered pyrolytic graphite. It appeared that the presence of two additional CH2 groups in the alkyl chain resulted in the formation of different surface structures. Scanning electron microscopy and atomic force microscopy showed that the palmitic acid microcrystallites were more asymmetric than those of the stearic acid, where the palmitic acid microcrystallites were observed to be an angular abutment in the scanning electron micrographs. The principal differences between the two types of long-chain saturated fatty acid crystallites were the larger density of peaks in the upper contact plane of the palmitic acid crystallites, as well as their greater proportion of asymmetrical shapes, in comparison to that of the stearic acid film. These two parameters might contribute to higher bactericidal activity on surfaces derived from palmitic acid. Both the palmitic and stearic acid crystallite surfaces displayed activity against Gram-negative, rod-shaped Pseudomonas aeruginosa and Gram-positive, spherical Staphylococcus aureus cells. These microcrystallite interfaces might be a useful tool in the fabrication of effective bactericidal nanocoatings. STATEMENT OF SIGNIFICANCE Nanostructured cicada and dragonfly wing surfaces have been discovered to be able physically kill bacterial cells. Here, we report on the successful fabrication of bactericidal three-dimensional structures of two main lipid components of the epicuticle of insect wings, palmitic (C16) and stearic (C18) acids. After crystallisation onto highly ordered pyrolytic graphite, both the palmitic and stearic acid films displayed bactericidal activity against both Gram-negative Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus cells. The simplicity of the production of these microcrystallite interfaces suggests that a fabrication technique, based on solution deposition, could be an effective technique for the application of bactericidal nanocoatings.
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Nguyen DHK, Pham VTH, Al Kobaisi M, Bhadra C, Orlowska A, Ghanaati S, Manzi BM, Baulin VA, Joudkazis S, Kingshott P, Crawford RJ, Ivanova EP. Adsorption of Human Plasma Albumin and Fibronectin onto Nanostructured Black Silicon Surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:10744-10751. [PMID: 27718587 DOI: 10.1021/acs.langmuir.6b02601] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The protein adsorption of two human plasma proteins-albumin (Alb) and fibronectin (Fn)-onto synthetic nanostructured bactericidal material-black silicon (bSi) surfaces (that contain an array of nanopillars) and silicon wafer (nonstructured) surfaces-was investigated. The adsorption behavior of Alb and Fn onto two types of substrata was studied using a combination of complementary analytical techniques. A two-step Alb adsorption mechanism onto the bSi surface has been proposed. At low bulk concentrations (below 40 μg/mL), the Alb preferentially adsorbed at the base of the nanopillars. At higher bulk concentrations, the Alb adsorbed on the top of the nanopillars. In the case of Fn, the protein preferentially adsorbed on the top of the nanopillars, irrespective of its bulk concentration.
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Affiliation(s)
- Duy H K Nguyen
- Department of Chemistry and Biotechnology, Faculty of Science, Engineering and Technology, Swinburne University of Technology , Hawthorn VIC 3122, Australia
| | - Vy T H Pham
- Department of Chemistry and Biotechnology, Faculty of Science, Engineering and Technology, Swinburne University of Technology , Hawthorn VIC 3122, Australia
| | - Mohammad Al Kobaisi
- Department of Chemistry and Biotechnology, Faculty of Science, Engineering and Technology, Swinburne University of Technology , Hawthorn VIC 3122, Australia
| | - Chris Bhadra
- Department of Chemistry and Biotechnology, Faculty of Science, Engineering and Technology, Swinburne University of Technology , Hawthorn VIC 3122, Australia
| | - Anna Orlowska
- Frankfurt Orofacial Regenerative Medicine, University Hospital Frankfurt , Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany
| | - Shahram Ghanaati
- Frankfurt Orofacial Regenerative Medicine, University Hospital Frankfurt , Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany
| | - Berardo Mario Manzi
- Department d'Enginyeria Quimica, Universitat Rovira i Virgili , 26 Av. dels Paisos Catalans, 43007 Tarragona, Spain
| | - Vladimir A Baulin
- Department d'Enginyeria Quimica, Universitat Rovira i Virgili , 26 Av. dels Paisos Catalans, 43007 Tarragona, Spain
| | - Saulius Joudkazis
- Department of Chemistry and Biotechnology, Faculty of Science, Engineering and Technology, Swinburne University of Technology , Hawthorn VIC 3122, Australia
| | - Peter Kingshott
- Department of Chemistry and Biotechnology, Faculty of Science, Engineering and Technology, Swinburne University of Technology , Hawthorn VIC 3122, Australia
| | - Russell J Crawford
- School of Science, College of Science, Engineering and Health, RMIT University , Melbourne VIC 3001, Australia
| | - Elena P Ivanova
- Department of Chemistry and Biotechnology, Faculty of Science, Engineering and Technology, Swinburne University of Technology , Hawthorn VIC 3122, Australia
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