1
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Hadady H, Alam A, Khurana I, Mutreja I, Kumar D, Shankar MR, Dua R. Optimizing alkaline hydrothermal treatment for biomimetic smart metallic orthopedic and dental implants. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2024; 35:31. [PMID: 38896291 PMCID: PMC11186882 DOI: 10.1007/s10856-024-06794-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Accepted: 04/04/2024] [Indexed: 06/21/2024]
Abstract
Orthopedic and dental implant failure continues to be a significant concern due to localized bacterial infections. Previous studies have attempted to improve implant surfaces by modifying their texture and roughness or coating them with antibiotics to enhance antibacterial properties for implant longevity. However, these approaches have demonstrated limited effectiveness. In this study, we attempted to engineer the titanium (Ti) alloy surface biomimetically at the nanometer scale, inspired by the cicada wing nanostructure using alkaline hydrothermal treatment (AHT) to simultaneously confer antibacterial properties and support the adhesion and proliferation of mammalian cells. The two modified Ti surfaces were developed using a 4 h and 8 h AHT process in 1 N NaOH at 230 °C, followed by a 2-hour post-calcination at 600 °C. We found that the control plates showed a relatively smooth surface, while the treatment groups (4 h & 8 h AHT) displayed nanoflower structures containing randomly distributed nano-spikes. The results demonstrated a statistically significant decrease in the contact angle of the treatment groups, which increased wettability characteristics. The 8 h AHT group exhibited the highest wettability and significant increase in roughness 0.72 ± 0.08 µm (P < 0.05), leading to more osteoblast cell attachment, reduced cytotoxicity effects, and enhanced relative survivability. The alkaline phosphatase activity measured in all different groups indicated that the 8 h AHT group exhibited the highest activity, suggesting that the surface roughness and wettability of the treatment groups may have facilitated cell adhesion and attachment and subsequently increased secretion of extracellular matrix. Overall, the findings indicate that biomimetic nanotextured surfaces created by the AHT process have the potential to be translated as implant coatings to enhance bone regeneration and implant integration.
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Affiliation(s)
- Hanieh Hadady
- Polymer & Material Science Research, Department of Innovation & Technology Research, American Dental Association Science & Research Institute, L.L.C., Gaithersburg, MD, USA
| | - Arefin Alam
- Polymer & Material Science Research, Department of Innovation & Technology Research, American Dental Association Science & Research Institute, L.L.C., Gaithersburg, MD, USA
| | - Indu Khurana
- Department of Economics and Business, Hampden-Sydney College, Hampden-, Sydney, VA, USA
| | - Isha Mutreja
- Minnesota Dental Research Center for Biomaterials and Biomechanics, Department of Restorative Sciences, University of Minnesota, Minneapolis, MN, USA
| | - Dhiraj Kumar
- Division of Pediatric Dentistry, School of Dentistry, University of Minnesota, Minneapolis, MN, USA
| | - Mamilla Ravi Shankar
- Department of Mechanical Engineering, Indian Institute of Technology, Tirupati, AP, India
| | - Rupak Dua
- Polymer & Material Science Research, Department of Innovation & Technology Research, American Dental Association Science & Research Institute, L.L.C., Gaithersburg, MD, USA.
- Department of Chemical Engineering, Hampton University, Hampton, VA, USA.
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2
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Wu KZ, Le Z, Myint B, Chan B, Liu L, Huang H, Sing SL, Tay A. Bioactive coating provides antimicrobial protection through immunomodulation and phage therapeutics. Mater Today Bio 2024; 26:101022. [PMID: 38525309 PMCID: PMC10959705 DOI: 10.1016/j.mtbio.2024.101022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 03/07/2024] [Accepted: 03/09/2024] [Indexed: 03/26/2024] Open
Abstract
Medical implant-associated infections (IAI) is a growing threat to patients undergoing implantation surgery. IAI prevention typically relies on medical implants endowed with bactericidal properties achieved through surface modifications with antibiotics. However, the clinical efficacy of this traditional paradigm remains suboptimal, often necessitating revision surgery and posing potentially lethal consequences for patients. To bolster the existing anti-IAI arsenal, we propose herein a chitosan-based bioactive coating, i.e., ChitoAntibac, which exerts bacteria-inhibitory effects either through immune modulation or phage-directed microbial clearance, without relying on conventional antibiotics. The immuno-stimulating effects and phage-induced bactericidal properties can be tailored by engineering the loading dynamic of macrophage migration inhibitory factor (MIF), which polarizes macrophages towards the proinflammatory subtype (M1) with enhanced bacterial phagocytosis, and Staphylococcal Phage K, resulting in rapid and targeted pathogenic clearance (>99.99%) in less than 8 h. Our innovative antibacterial coating opens a new avenue in the pursuit of effective IAI prevention through immuno-stimulation and phage therapeutics.
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Affiliation(s)
- Kenny Zhuoran Wu
- Department of Biomedical Engineering, College of Design and Engineering, National University of Singapore, 119276, Singapore
| | - Zhicheng Le
- Department of Biomedical Engineering, College of Design and Engineering, National University of Singapore, 119276, Singapore
- Institute for Health Innovation & Technology, National University of Singapore, 117599, Singapore
| | - Ba Myint
- Department of Biomedical Engineering, College of Design and Engineering, National University of Singapore, 119276, Singapore
- Institute for Health Innovation & Technology, National University of Singapore, 117599, Singapore
| | - Brian Chan
- Department of Biomedical Engineering, College of Design and Engineering, National University of Singapore, 119276, Singapore
| | - Ling Liu
- Institute for Health Innovation & Technology, National University of Singapore, 117599, Singapore
| | - Hua Huang
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 117597, Singapore
- Electrophysiology Core Facility, Yong Loo Lin School of Medicine, National University of Singapore, 117456, Singapore
- Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore: Level 5, Centre for Life Sciences, 28 Medical Drive, 117456, Singapore
| | - Swee Leong Sing
- NUS Tissue Engineering Program, National University of Singapore, 117510, Singapore
- Department of Mechanical Engineering, College of Design and Engineering, National University of Singapore, 117575, Singapore
| | - Andy Tay
- Department of Biomedical Engineering, College of Design and Engineering, National University of Singapore, 119276, Singapore
- Institute for Health Innovation & Technology, National University of Singapore, 117599, Singapore
- NUS Tissue Engineering Program, National University of Singapore, 117510, Singapore
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3
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Ishak MI, Delint RC, Liu X, Xu W, Tsimbouri PM, Nobbs AH, Dalby MJ, Su B. Nanotextured titanium inhibits bacterial activity and supports cell growth on 2D and 3D substrate: A co-culture study. BIOMATERIALS ADVANCES 2024; 158:213766. [PMID: 38232578 DOI: 10.1016/j.bioadv.2024.213766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 12/14/2023] [Accepted: 01/08/2024] [Indexed: 01/19/2024]
Abstract
Medical implant-associated infections pose a significant challenge to modern medicine, with aseptic loosening and bacterial infiltration being the primary causes of implant failure. While nanostructured surfaces have demonstrated promising antibacterial properties, the translation of their efficacy from 2D to 3D substrates remains a challenge. Here, we used scalable alkaline etching to fabricate nanospike and nanonetwork topologies on 2D and laser powder-bed fusion printed 3D titanium. The fabricated surfaces were compared with regard to their antibacterial properties against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, and mesenchymal stromal cell responses with and without the presence of bacteria. Finite elemental analysis assessed the mechanical properties and permeability of the 3D substrate. Our findings suggest that 3D nanostructured surfaces have potential to both prevent implant infections and allow host cell integration. This work represents a significant step towards developing effective and scalable fabrication methods on 3D substrates with consistent and reproducible antibacterial activity, with important implications for the future of medical implant technology.
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Affiliation(s)
- Mohd I Ishak
- Bristol Dental School, University of Bristol, Lower Maudlin Street, Bristol BS1 2LY, UK; School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK
| | - Rosalia Cuahtecontzi Delint
- Centre for the Cellular Microenvironment, School of Biomedical Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Xiayi Liu
- Bristol Dental School, University of Bristol, Lower Maudlin Street, Bristol BS1 2LY, UK
| | - Wei Xu
- National Engineering Research Center for Advanced Rolling and Intelligent Manufacturing, Institute of Engineering Technology, University of Science and Technology Beijing, Beijing 100083, China
| | - Penelope M Tsimbouri
- Centre for the Cellular Microenvironment, School of Biomedical Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Angela H Nobbs
- Bristol Dental School, University of Bristol, Lower Maudlin Street, Bristol BS1 2LY, UK
| | - Matthew J Dalby
- Centre for the Cellular Microenvironment, School of Biomedical Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Bo Su
- Bristol Dental School, University of Bristol, Lower Maudlin Street, Bristol BS1 2LY, UK.
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4
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Hayles A, Bright R, Nguyen NH, Truong VK, Vongsvivut J, Wood J, Kidd SP, Vasilev K. Staphylococcus aureus surface attachment selectively influences tolerance against charged antibiotics. Acta Biomater 2024; 175:369-381. [PMID: 38141932 DOI: 10.1016/j.actbio.2023.12.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 11/21/2023] [Accepted: 12/17/2023] [Indexed: 12/25/2023]
Abstract
The threat of infection during implant placement surgery remains a considerable burden for millions of patients worldwide. To combat this threat, clinicians employ a range of anti-infective strategies and practices. One of the most common interventions is the use of prophylactic antibiotic treatment during implant placement surgery. However, these practices can be detrimental by promoting the resilience of biofilm-forming bacteria and enabling them to persist throughout treatment and re-emerge later, causing a life-threatening infection. Thus, it is of the utmost importance to elucidate the events occurring during the initial stages of bacterial surface attachment and determine whether any biological processes may be targeted to improve surgical outcomes. Using gene expression analysis, we identified a cellular mechanism of S. aureus which modifies its cell surface charge following attachment to a medical grade titanium surface. We determined the upregulation of two systems involved in the d-alanylation of teichoic acids and the lysylation of phosphatidylglycerol. We supported these molecular findings by utilizing synchrotron-sourced attenuated total reflection Fourier-transform infrared microspectroscopy to analyze the biomolecular properties of the S. aureus cell surface following attachment. As a direct consequence, S. aureus quickly becomes substantially more tolerant to the positively charged vancomycin, but not the negatively charged cefazolin. The present study can assist clinicians in rationally selecting the most potent antibiotic in prophylaxis treatments. Furthermore, it highlights a cellular process that could potentially be targeted by novel technologies and strategies to improve the outcome of antibiotic prophylaxis during implant placement surgery. STATEMENT OF SIGNIFICANCE: The antibiotic tolerance of bacteria in biofilm is a well-established phenomenon. However, the physiological adaptations employed by Staphylococcus aureus to increase its antibiotic tolerance during the early stages of surface attachment are poorly understood. Using multiple techniques, including gene expression analysis and synchrotron-sourced Fourier-transform infrared microspectroscopy, we generated insights into the physiological response of S. aureus following attachment to a medical grade titanium surface. We showed that this phenotypic transition enables S. aureus to better tolerate the positively charged vancomycin, but not the negatively charged cefazolin. These findings shed light on the antibiotic tolerance mechanisms employed by S. aureus to survive prophylactically administered antibiotics and can help clinicians to protect patients from infections.
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Affiliation(s)
- Andrew Hayles
- College of Medicine and Public Health, Flinders University, Bedford Park, South Australia, 5042 Australia.
| | - Richard Bright
- College of Medicine and Public Health, Flinders University, Bedford Park, South Australia, 5042 Australia
| | - Ngoc Huu Nguyen
- School of Biomedical Engineering, Faculty of Engineering, University of Sydney, Sydney, Australia
| | - Vi Khanh Truong
- College of Medicine and Public Health, Flinders University, Bedford Park, South Australia, 5042 Australia
| | - Jitraporn Vongsvivut
- Infrared Microspectroscopy (IRM) Beamline, ANSTO ‒ Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168, Australia
| | - Jonathan Wood
- Academic Unit of STEM, University of South Australia, Adelaide 5095, South Australia, Australia
| | - Stephen P Kidd
- Department of Molecular and Biomedical Sciences, School of Biological Sciences, The University of Adelaide, Adelaide, SA 5005, Australia; Australian Centre for Antimicrobial Resistance Ecology, The University of Adelaide, Adelaide, SA 5005, Australia
| | - Krasimir Vasilev
- College of Medicine and Public Health, Flinders University, Bedford Park, South Australia, 5042 Australia.
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5
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Wood J, Bright R, Palms D, Barker D, Vasilev K. Damage Behavior with Atomic Force Microscopy on Anti-Bacterial Nanostructure Arrays. NANOMATERIALS (BASEL, SWITZERLAND) 2024; 14:253. [PMID: 38334525 PMCID: PMC10857006 DOI: 10.3390/nano14030253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 01/17/2024] [Accepted: 01/19/2024] [Indexed: 02/10/2024]
Abstract
The atomic force microscope is a versatile tool for assessing the topography, friction, and roughness of a broad spectrum of surfaces, encompassing anti-bacterial nanostructure arrays. Measuring and comparing all these values with one instrument allows clear comparisons of many nanomechanical reactions and anomalies. Increasing nano-Newton-level forces through the cantilever tip allows for the testing and measuring of failure points, damage behavior, and functionality under unfavorable conditions. Subjecting a grade 5 titanium alloy to hydrothermally etched nanostructures while applying elevated cantilever tip forces resulted in the observation of irreversible damage through atomic force microscopy. Despite the damage, a rough and non-uniform morphology remained that may still allow it to perform in its intended application as an anti-bacterial implant surface. Utilizing an atomic force microscope enables the evaluation of these surfaces before their biomedical application.
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Affiliation(s)
- Jonathan Wood
- Future Industries Institute, University of South Australia, Mawson Lakes, SA 5095, Australia;
| | - Richard Bright
- College of Medicine and Public Health, Flinders University, Bedford Park, SA 5042, Australia;
| | - Dennis Palms
- College of Medicine and Public Health, Flinders University, Bedford Park, SA 5042, Australia;
| | - Dan Barker
- Corin Australia, Sydney, NSW 2153, Australia;
| | - Krasimir Vasilev
- College of Medicine and Public Health, Flinders University, Bedford Park, SA 5042, Australia;
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6
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Rawat N, Benčina M, Paul D, Kovač J, Lakota K, Žigon P, Kralj-Iglič V, Ho HC, Vukomanović M, Iglič A, Junkar I. Fine-Tuning the Nanostructured Titanium Oxide Surface for Selective Biological Response. ACS APPLIED BIO MATERIALS 2023; 6:5481-5492. [PMID: 38062750 PMCID: PMC10731649 DOI: 10.1021/acsabm.3c00686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 11/07/2023] [Accepted: 11/20/2023] [Indexed: 12/19/2023]
Abstract
Cardiovascular diseases are a pre-eminent global cause of mortality in the modern world. Typically, surgical intervention with implantable medical devices such as cardiovascular stents is deployed to reinstate unobstructed blood flow. Unfortunately, existing stent materials frequently induce restenosis and thrombosis, necessitating the development of superior biomaterials. These biomaterials should inhibit platelet adhesion (mitigating stent-induced thrombosis) and smooth muscle cell proliferation (minimizing restenosis) while enhancing endothelial cell proliferation at the same time. To optimize the surface properties of Ti6Al4V medical implants, we investigated two surface treatment procedures: gaseous plasma treatment and hydrothermal treatment. We analyzed these modified surfaces through scanning electron microscopy (SEM), water contact angle analysis (WCA), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) analysis. Additionally, we assessed in vitro biological responses, including platelet adhesion and activation, as well as endothelial and smooth muscle cell proliferation. Herein, we report the influence of pre/post oxygen plasma treatment on titanium oxide layer formation via a hydrothermal technique. Our results indicate that alterations in the titanium oxide layer and surface nanotopography significantly influence cell interactions. This work offers promising insights into designing multifunctional biomaterial surfaces that selectively promote specific cell types' proliferation─which is a crucial advancement in next-generation vascular implants.
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Affiliation(s)
- Niharika Rawat
- Laboratory
of Physics, Faculty of Electrical Engineering,
University of Ljubljana, Tržaška 25, SI-1000 Ljubljana, Slovenia
| | - Metka Benčina
- Laboratory
of Physics, Faculty of Electrical Engineering,
University of Ljubljana, Tržaška 25, SI-1000 Ljubljana, Slovenia
- Department
of Surface Engineering, Jožef Stefan
Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
| | - Domen Paul
- Department
of Surface Engineering, Jožef Stefan
Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
| | - Janez Kovač
- Department
of Surface Engineering, Jožef Stefan
Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
| | - Katja Lakota
- Department
of Rheumatology, University Medical Centre
Ljubljana, Vodnikova 62, SI-1000 Ljubljana, Slovenia
| | - Polona Žigon
- Department
of Rheumatology, University Medical Centre
Ljubljana, Vodnikova 62, SI-1000 Ljubljana, Slovenia
| | - Veronika Kralj-Iglič
- Laboratory
of Clinical Biophysics, Faculty of Health
Sciences, University of Ljubljana, Zdravstvena pot 5, SI-1000 Ljubljana, Slovenia
| | - Hsin-Chia Ho
- Advanced
Materials Department, Jožef Stefan
Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
| | - Marija Vukomanović
- Advanced
Materials Department, Jožef Stefan
Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
| | - Aleš Iglič
- Laboratory
of Physics, Faculty of Electrical Engineering,
University of Ljubljana, Tržaška 25, SI-1000 Ljubljana, Slovenia
- Chair of
Orthopaedic Surgery, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, SI-1000 Ljubljana, Slovenia
| | - Ita Junkar
- Department
of Surface Engineering, Jožef Stefan
Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
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7
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Xing Z, Guo J, Wu Z, He C, Wang L, Bai M, Liu X, Zhu B, Guan Q, Cheng C. Nanomaterials-Enabled Physicochemical Antibacterial Therapeutics: Toward the Antibiotic-Free Disinfections. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2303594. [PMID: 37626465 DOI: 10.1002/smll.202303594] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 07/17/2023] [Indexed: 08/27/2023]
Abstract
Bacterial infection continues to be an increasing global health problem with the most widely accepted treatment paradigms restricted to antibiotics. However, the overuse and misuse of antibiotics have triggered multidrug resistance of bacteria, frustrating therapeutic outcomes, and leading to higher mortality rates. Even worse, the tendency of bacteria to form biofilms on living and nonliving surfaces further increases the difficulty in confronting bacteria because the extracellular matrix can act as a robust barrier to prevent the penetration of antibiotics and resist environmental damage. As a result, the inability to eliminate bacteria and biofilms often leads to persistent infection, implant failure, and device damage. Therefore, it is of paramount importance to develop alternative antimicrobial agents while avoiding the generation of bacterial resistance to prevent the large-scale growth of bacterial resistance. In recent years, nano-antibacterial materials have played a vital role in the antibacterial field because of their excellent physical and chemical properties. This review focuses on new physicochemical antibacterial strategies and versatile antibacterial nanomaterials, especially the mechanism and types of 2D antibacterial nanomaterials. In addition, this advanced review provides guidance on the development direction of antibiotic-free disinfections in the antibacterial field in the future.
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Affiliation(s)
- Zhenyu Xing
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, 610065, China
| | - Jiusi Guo
- Department of Orthodontics, Department of Endodontics, State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Zihe Wu
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, 610065, China
| | - Chao He
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, 610065, China
| | - Liyun Wang
- Department of Medical Ultrasound, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Mingru Bai
- Department of Orthodontics, Department of Endodontics, State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Xikui Liu
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, 610065, China
| | - Bihui Zhu
- Department of Medical Ultrasound, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Qiuyue Guan
- Department of Geriatrics, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, China
| | - Chong Cheng
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, 610065, China
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8
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Hayles A, Bright R, Nguyen NH, Truong VK, Wood J, Palms D, Vongsvivut J, Barker D, Vasilev K. Vancomycin tolerance of adherent Staphylococcus aureus is impeded by nanospike-induced physiological changes. NPJ Biofilms Microbiomes 2023; 9:90. [PMID: 38030708 PMCID: PMC10687013 DOI: 10.1038/s41522-023-00458-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 11/10/2023] [Indexed: 12/01/2023] Open
Abstract
Bacterial colonization of implantable biomaterials is an ever-pervasive threat that causes devastating infections, yet continues to elude resolution. In the present study, we report how a rationally designed antibacterial surface containing sharp nanospikes can enhance the susceptibility of pathogenic bacteria to antibiotics used in prophylactic procedures. We show that Staphylococcus aureus, once adhered to a titanium surface, changes its cell-surface charge to increase its tolerance to vancomycin. However, if the Ti surface is modified to bear sharp nanospikes, the activity of vancomycin is rejuvenated, leading to increased bacterial cell death through synergistic activity. Analysis of differential gene expression provided evidence of a set of genes involved with the modification of cell surface charge. Synchrotron-sourced attenuated Fourier-transform infrared microspectroscopy (ATR-FTIR), together with multivariate analysis, was utilized to further elucidate the biochemical changes of S. aureus adhered to nanospikes. By inhibiting the ability of the pathogen to reduce its net negative charge, the nanoengineered surface renders S. aureus more susceptible to positively charged antimicrobials such as vancomycin. This finding highlights the opportunity to enhance the potency of prophylactic antibiotic treatments during implant placement surgery by employing devices having surfaces modified with spike-like nanostructures.
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Affiliation(s)
- Andrew Hayles
- College of Medicine and Public Health, Flinders University, Bedford Park, SA, 5042, Australia
| | - Richard Bright
- College of Medicine and Public Health, Flinders University, Bedford Park, SA, 5042, Australia
| | - Ngoc Huu Nguyen
- School of Biomedical Engineering, Faculty of Engineering, University of Sydney, Sydney, Australia
| | - Vi Khanh Truong
- College of Medicine and Public Health, Flinders University, Bedford Park, SA, 5042, Australia
| | - Jonathan Wood
- Academic Unit of STEM, University of South Australia, Mawson Lakes, Adelaide, 5095, SA, Australia
| | - Dennis Palms
- College of Medicine and Public Health, Flinders University, Bedford Park, SA, 5042, Australia
| | - Jitraporn Vongsvivut
- Infrared Microspectroscopy (IRM) Beamline, ANSTO ‒ Australian Synchrotron, 800 Blackburn Road, Clayton, VIC, 3168, Australia
| | - Dan Barker
- Corin Australia, Baulkham Hills, NSW, 2153, Australia
| | - Krasimir Vasilev
- College of Medicine and Public Health, Flinders University, Bedford Park, SA, 5042, Australia.
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9
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Senevirathne SWMAI, Mathew A, Toh YC, Yarlagadda PKDV. Preferential adhesion of bacterial cells onto top- and bottom-mounted nanostructured surfaces under flow conditions. NANOSCALE ADVANCES 2023; 5:6458-6472. [PMID: 38024307 PMCID: PMC10662052 DOI: 10.1039/d3na00581j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 10/07/2023] [Indexed: 12/01/2023]
Abstract
The bactericidal effect of biomimetic nanostructured surfaces has been known for a long time, with recent data suggesting an enhanced efficiency of the nanostructured surfaces under fluid shear. While some of the influential factors on the bactericidal effect of nanostructured surfaces under fluid shear are understood, there are numerous important factors yet to be studied, which is essential for the successful implementation of this technology in industrial applications. Among those influential factors, the orientation of the nanostructured surface can play an important role in bacterial cell adhesion onto surfaces. Gravitational effects can become dominant under low flow velocities, making the diffusive transport of bacterial cells more prominent than the advective transport. However, the role of nanostructure orientation in determining its bactericidal efficiency under flow conditions is still not clear. In this study, we analysed the effect of surface orientation of nanostructured surfaces, along with bacterial cell concentration, fluid flow rate, and the duration of time which the surface is exposed to flow, on bacterial adhesion and viability on these surfaces. Two surface orientations, with one on the top and the other on the bottom of a flow channel, were studied. Under flow conditions, the bactericidal efficacy of the nanostructured surface is both orientation and bacterial species dependent. The effects of cell concentration, fluid flow rate, and exposure time on cell adhesion are independent of the nanostructured surface orientation. Fluid shear showed a species-dependent effect on bacterial adhesion, while the effects of concentration and exposure time on bacterial cell adhesion are independent of the bacterial species. Moreover, bacterial cells demonstrate preferential adhesion onto surfaces based on the surface orientation, and these effects are species dependent. These results outline the capabilities and limitations of nanostructures under flow conditions. This provides valuable insights into the applications of nanostructures in medical or industrial sectors, which are associated with overlaying fluid flow.
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Affiliation(s)
- S W M A Ishantha Senevirathne
- Queensland University of Technology, Faculty of Engineering, School of Mechanical, Medical, and Process Engineering Brisbane QLD 4000 Australia
- Queensland University of Technology, Centre for Biomedical Technologies Brisbane QLD 4000 Australia
| | - Asha Mathew
- Queensland University of Technology, Faculty of Engineering, School of Mechanical, Medical, and Process Engineering Brisbane QLD 4000 Australia
- Queensland University of Technology, Centre for Biomedical Technologies Brisbane QLD 4000 Australia
| | - Yi-Chin Toh
- Queensland University of Technology, Faculty of Engineering, School of Mechanical, Medical, and Process Engineering Brisbane QLD 4000 Australia
- Queensland University of Technology, Centre for Biomedical Technologies Brisbane QLD 4000 Australia
| | - Prasad K D V Yarlagadda
- School of Engineering, University of Southern Queensland, Springfield Campus Springfield Central QLD 4300 Australia
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10
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Georgakopoulos-Soares I, Papazoglou EL, Karmiris-Obratański P, Karkalos NE, Markopoulos AP. Surface antibacterial properties enhanced through engineered textures and surface roughness: A review. Colloids Surf B Biointerfaces 2023; 231:113584. [PMID: 37837687 DOI: 10.1016/j.colsurfb.2023.113584] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 10/04/2023] [Accepted: 10/09/2023] [Indexed: 10/16/2023]
Abstract
The spread of bacteria through contaminated surfaces is a major issue in healthcare, food industry, and other economic sectors. The widespread use of antibiotics is not a sustainable solution in the long term due to the development of antibiotic resistance. Therefore, surfaces with antibacterial properties have the potential to be a disruptive approach to combat microbial contamination. Different methods and approaches have been studied to impart or enhance antibacterial properties on surfaces. The surface roughness and texture are inherent parameters that significantly impact the antibacterial properties of a surface. They are also directly related to the previously employed machining and treatment methods. This review article discusses the correlation between surface roughness and antibacterial properties is presented and discussed. It begins with an introduction to the concepts of surface roughness and texture, followed by a description of the most commonly utilized machining methods and surface. A thorough analysis of bacterial adhesion and growth is then presented. Finally, the most recent studies in this research area are comprehensively reviewed. The studies are sorted and classified based on the utilized machining and treatment methods, which are divided into mechanical processes, surface treatments and coatings. Through the systematic review and record of the recent advances, the authors aim to assist and promote further research in this very promising and extremely important direction, by providing a systematic review of recent advances.
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Affiliation(s)
- Ilias Georgakopoulos-Soares
- Institute for Personalized Medicine, Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA, USA; School of Mechanical Engineering, Section of Manufacturing Technology, National Technical University of Athens, Heroon Polytechniou 9, 15780 Athens, Greece
| | - Emmanouil L Papazoglou
- School of Mechanical Engineering, Section of Manufacturing Technology, National Technical University of Athens, Heroon Polytechniou 9, 15780 Athens, Greece
| | - Panagiotis Karmiris-Obratański
- Department of Manufacturing Systems, Faculty of Mechanical Engineering and Robotics, AGH University of Krakow, 30-059 Cracow, Poland.
| | - Nikolaos E Karkalos
- School of Mechanical Engineering, Section of Manufacturing Technology, National Technical University of Athens, Heroon Polytechniou 9, 15780 Athens, Greece
| | - Angelos P Markopoulos
- School of Mechanical Engineering, Section of Manufacturing Technology, National Technical University of Athens, Heroon Polytechniou 9, 15780 Athens, Greece
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11
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Morel J, McNeilly O, Grundy S, Brown T, Gunawan C, Amal R, Scott JA. Nanoscale Titanium Surface Engineering via Low-Temperature Hydrothermal Etching for Enhanced Antimicrobial Properties. ACS APPLIED MATERIALS & INTERFACES 2023; 15:46247-46260. [PMID: 37738302 DOI: 10.1021/acsami.3c09525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/24/2023]
Abstract
Bioinspired nanotopography artificially fabricated on titanium surfaces offers a solution for the rising issue of postoperative infections within orthopedics. On a small scale, hydrothermal etching has proven to deliver an effective antimicrobial nanospike surface. However, translation to an industrial setting is limited by the elevated synthesis temperature (150 °C) and associated equipment requirements. Here, for the first time, we fabricate surface nanostructures using comparatively milder synthesis temperatures (75 °C), which deliver physicochemical properties and antimicrobial capability comparable to the high-temperature surface. Using a KOH etchant, the simultaneous formation of titania and titanate crystals at both temperatures produces a one-dimensional nanostructure array. Analysis indicated that the formation mechanism comprises dissolution and reprecipitation processes, identifying the deposited titanates as hydrated layered tetra-titanates (K2Ti4O9·nH2O). A proposed nanospike formation mechanism was confirmed through the identification of a core and outer shell for individual nanostructures, primarily comprised of titanates and titania, respectively. Etching conditions dictated crystalline formation, favoring a thicker titanate core for nanorods under higher synthesis temperatures and etchant concentrations. A bactericidal investigation showed the efficacy against Gram-negative bacteria for a representative low-temperature nanosurface (34.4 ± 14.4%) was comparable to the higher temperature nanosurface (34.0 ± 17.0%), illustrating the potential of low-temperature hydrothermal synthesis. Our results provide valuable insight into the applicability of low-temperature etching protocols that are more favorable in large-scale manufacturing settings.
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Affiliation(s)
- James Morel
- School of Chemical Engineering, University of New South Wales, Kensington, NSW 2052, Australia
| | - Oliver McNeilly
- Australian Institute for Microbiology and Infection, University of Technology Sydney, Broadway, NSW 2007, Australia
| | - Sarah Grundy
- School of Chemical Engineering, University of New South Wales, Kensington, NSW 2052, Australia
| | - Toby Brown
- Corin Australia, Pymble, NSW 2073, Australia
| | - Cindy Gunawan
- Australian Institute for Microbiology and Infection, University of Technology Sydney, Broadway, NSW 2007, Australia
| | - Rose Amal
- School of Chemical Engineering, University of New South Wales, Kensington, NSW 2052, Australia
| | - Jason A Scott
- School of Chemical Engineering, University of New South Wales, Kensington, NSW 2052, Australia
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12
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Bright R, Hayles A, Wood J, Palms D, Barker D, Vasilev K. Interplay between Immune and Bacterial Cells on a Biomimetic Nanostructured Surface: A "Race for the Surface" Study. ACS APPLIED BIO MATERIALS 2023; 6:3472-3483. [PMID: 37384836 DOI: 10.1021/acsabm.3c00351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/01/2023]
Abstract
Biomaterial-associated infection is an ever-increasing risk with devasting consequences for patients. Considerable research has been undertaken to address this issue by imparting antibacterial properties to the surface of biomedical implants. One approach that generated much interest over recent years was the generation of bioinspired bactericidal nanostructures. In the present report, we have investigated the interplay between macrophages and bacteria on antibacterial nanostructured surfaces to determine the outcome of the so-called "race for the surface". Our results showed that macrophages can indeed outcompete Staphylococcus aureus via multiple mechanisms. The early generation of reactive oxygen species by macrophages, downregulation of bacterial virulence gene expression, and the bactericidal nature of the nanostructured surface itself collectively acted to help the macrophage to win the race. This study highlights the potential of nanostructured surfaces to reduce infection rates and improve the long-term success of biomedical implants. This work can also serve as guidance to others to investigate in vitro host-bacteria interactions on other candidate antibacterial surfaces.
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Affiliation(s)
- Richard Bright
- College of Medicine and Public Health, Flinders University, Bedford Park, SA 5042, Australia
| | - Andrew Hayles
- College of Medicine and Public Health, Flinders University, Bedford Park, SA 5042, Australia
| | - Jonathan Wood
- Academic Unit of STEM, University of South Australia, Mawson Lakes, Adelaide, SA 5095, Australia
| | - Dennis Palms
- College of Medicine and Public Health, Flinders University, Bedford Park, SA 5042, Australia
| | - Dan Barker
- Corin Australia, Sydney, NSW 2153, Australia
| | - Krasimir Vasilev
- College of Medicine and Public Health, Flinders University, Bedford Park, SA 5042, Australia
- Academic Unit of STEM, University of South Australia, Mawson Lakes, Adelaide, SA 5095, Australia
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13
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Vasilev K. Antibacterial Applications of Nanomaterials. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:nano13091530. [PMID: 37177075 PMCID: PMC10180340 DOI: 10.3390/nano13091530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Accepted: 04/20/2023] [Indexed: 05/15/2023]
Abstract
In the 21st century, infections remain a major problem for society and are one of the leading causes of mortality [...].
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Affiliation(s)
- Krasimir Vasilev
- College of Medicine and Public Health, Flinders University, Bedford Park, SA 5042, Australia
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14
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da Silva IR, Barreto ATDS, Seixas RS, Paes PNG, Lunz JDN, Thiré RMDSM, Jardim PM. Novel Strategy for Surface Modification of Titanium Implants towards the Improvement of Osseointegration Property and Antibiotic Local Delivery. MATERIALS (BASEL, SWITZERLAND) 2023; 16:2755. [PMID: 37049048 PMCID: PMC10095684 DOI: 10.3390/ma16072755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 03/20/2023] [Accepted: 03/22/2023] [Indexed: 06/19/2023]
Abstract
The topography and chemical composition modification of titanium (Ti) implants play a decisive role in improving biocompatibility and bioactivity, accelerating osseointegration, and, thus, determining clinical success. In spite of the development of surface modification strategies, bacterial contamination is a common cause of failure. The use of systemic antibiotic therapy does not guarantee action at the contaminated site. In this work, we proposed a surface treatment for Ti implants that aim to improve their osseointegration and reduce bacterial colonization in surgery sites due to the local release of antibiotic. The Ti discs were hydrothermally treated with 3M NaOH solution to form a nanostructured layer of titanate on the Ti surface. Metronidazole was impregnated on these nanostructured surfaces to enable its local release. The samples were coated with poly(vinyl alcohol)-PVA films with different thickness to evaluate a possible control of drug release. Gamma irradiation was used to crosslink the polymer chains to achieve hydrogel layer formation and to sterilize the samples. The samples were characterized by XRD, SEM, FTIR, contact angle measurements, "in vitro" bioactivity, and drug release analysis. The alkaline hydrothermal treatment successfully produced intertwined, web-like nanostructures on the Ti surface, providing wettability and bioactivity to the Ti samples (Ti + TTNT samples). Metronidazole was successfully loaded and released from the Ti + TTNT samples coated or not with PVA. Although the polymeric film acted as a physical barrier to drug delivery, all groups reached the minimum inhibitory concentration for anaerobic bacteria. Thus, the surface modification method presented is a potential approach to improve the osseointegration of Ti implants and to associate local drug delivery with dental implants, preventing early infections and bone failure.
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Affiliation(s)
- Isabela Rocha da Silva
- COPPE/Program of Metallurgical and Materials Engineering (PEMM), Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-598, RJ, Brazil
| | - Aline Tavares da Silva Barreto
- Graduation Program in Nanobiosystems, Universidade Federal do Rio de Janeiro (UFRJ), Duque de Caxias 25240-005, RJ, Brazil
| | - Renata Santos Seixas
- COPPE/Program of Metallurgical and Materials Engineering (PEMM), Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-598, RJ, Brazil
| | - Paula Nunes Guimarães Paes
- Faculdade de Odontologia, Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro 20551-030, RJ, Brazil
| | - Juliana do Nascimento Lunz
- Divisão de Metrologia de Materiais, Instituto Nacional de Metrologia, Qualidade e Tecnologia (Inmetro), Xerem 25250-020, RJ, Brazil
| | - Rossana Mara da Silva Moreira Thiré
- COPPE/Program of Metallurgical and Materials Engineering (PEMM), Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-598, RJ, Brazil
| | - Paula Mendes Jardim
- COPPE/Program of Metallurgical and Materials Engineering (PEMM), Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-598, RJ, Brazil
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15
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Hasan J, Bright R, Hayles A, Palms D, Zilm P, Barker D, Vasilev K. Preventing Peri-implantitis: The Quest for a Next Generation of Titanium Dental Implants. ACS Biomater Sci Eng 2022; 8:4697-4737. [PMID: 36240391 DOI: 10.1021/acsbiomaterials.2c00540] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Titanium and its alloys are frequently the biomaterial of choice for dental implant applications. Although titanium dental implants have been utilized for decades, there are yet unresolved issues pertaining to implant failure. Dental implant failure can arise either through wear and fatigue of the implant itself or peri-implant disease and subsequent host inflammation. In the present report, we provide a comprehensive review of titanium and its alloys in the context of dental implant material, and how surface properties influence the rate of bacterial colonization and peri-implant disease. Details are provided on the various periodontal pathogens implicated in peri-implantitis, their adhesive behavior, and how this relationship is governed by the implant surface properties. Issues of osteointegration and immunomodulation are also discussed in relation to titanium dental implants. Some impediments in the commercial translation for a novel titanium-based dental implant from "bench to bedside" are discussed. Numerous in vitro studies on novel materials, processing techniques, and methodologies performed on dental implants have been highlighted. The present report review that comprehensively compares the in vitro, in vivo, and clinical studies of titanium and its alloys for dental implants.
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Affiliation(s)
- Jafar Hasan
- Academic Unit of STEM, University of South Australia, Mawson Lakes, SA 5095, Australia
| | - Richard Bright
- Academic Unit of STEM, University of South Australia, Mawson Lakes, SA 5095, Australia.,College of Medicine and Public Health, Flinders University, Bedford Park 5042, South Australia, Australia
| | - Andrew Hayles
- Academic Unit of STEM, University of South Australia, Mawson Lakes, SA 5095, Australia.,College of Medicine and Public Health, Flinders University, Bedford Park 5042, South Australia, Australia
| | - Dennis Palms
- Academic Unit of STEM, University of South Australia, Mawson Lakes, SA 5095, Australia.,College of Medicine and Public Health, Flinders University, Bedford Park 5042, South Australia, Australia
| | - Peter Zilm
- Adelaide Dental School, University of Adelaide, Adelaide, 5005, South Australia, Australia
| | - Dan Barker
- ANISOP Holdings, Pty. Ltd., 101 Collins St, Melbourne VIC, 3000 Australia
| | - Krasimir Vasilev
- Academic Unit of STEM, University of South Australia, Mawson Lakes, SA 5095, Australia.,College of Medicine and Public Health, Flinders University, Bedford Park 5042, South Australia, Australia
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16
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Bright R, Hayles A, Wood J, Palms D, Brown T, Barker D, Vasilev K. Surfaces Containing Sharp Nanostructures Enhance Antibiotic Efficacy. NANO LETTERS 2022; 22:6724-6731. [PMID: 35900125 DOI: 10.1021/acs.nanolett.2c02182] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The ever-increasing rate of medical device implantations is met by a proportionately high burden of implant-associated infections. To mitigate this threat, much research has been directed toward the development of antibacterial surface modifications by various means. One recent approach involves surfaces containing sharp nanostructures capable of killing bacteria upon contact. Herein, we report that the mechanical interaction between Staphylococcus aureus and such surface nanostructures leads to a sensitization of the pathogen to the glycopeptide antibiotic vancomycin. We demonstrate that this is due to cell wall damage and impeded bacterial defenses against reactive oxygen species. The results of this study promise to be impactful in the clinic, as a combination of nanostructured antibacterial surfaces and antibiotics commonly used in hospitals may improve antimicrobial therapy strategies, helping clinicians to prevent and treat implant-associated infections using reduced antibiotic concentrations instead of relying on invasive revision surgeries with often poor outcomes.
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Affiliation(s)
- Richard Bright
- Academic Unit of STEM, University of South Australia, Mawson Lakes, Adelaide 5095, South Australia, Australia
- College of Medicine and Public Health, Flinders University, Bedford Park 5042, South Australia, Australia
| | - Andrew Hayles
- Academic Unit of STEM, University of South Australia, Mawson Lakes, Adelaide 5095, South Australia, Australia
- College of Medicine and Public Health, Flinders University, Bedford Park 5042, South Australia, Australia
| | - Jonathan Wood
- Academic Unit of STEM, University of South Australia, Mawson Lakes, Adelaide 5095, South Australia, Australia
| | - Dennis Palms
- Academic Unit of STEM, University of South Australia, Mawson Lakes, Adelaide 5095, South Australia, Australia
| | - Toby Brown
- Corin Australia, Pymble 2073, New South Wales, Australia
| | - Dan Barker
- Corin Australia, Pymble 2073, New South Wales, Australia
| | - Krasimir Vasilev
- Academic Unit of STEM, University of South Australia, Mawson Lakes, Adelaide 5095, South Australia, Australia
- College of Medicine and Public Health, Flinders University, Bedford Park 5042, South Australia, Australia
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17
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Senevirathne SWAI, Toh YC, Yarlagadda PKDV. Fluid Flow Induces Differential Detachment of Live and Dead Bacterial Cells from Nanostructured Surfaces. ACS OMEGA 2022; 7:23201-23212. [PMID: 35847259 PMCID: PMC9280952 DOI: 10.1021/acsomega.2c01208] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Nanotopographic surfaces are proven to be successful in killing bacterial cells upon contact. This non-chemical bactericidal property has paved an alternative way of fighting bacterial colonization and associated problems, especially the issue of bacteria evolving resistance against antibiotic and antiseptic agents. Recent advancements in nanotopographic bactericidal surfaces have made them suitable for many applications in medical and industrial sectors. The bactericidal effect of nanotopographic surfaces is classically studied under static conditions, but the actual potential applications do have fluid flow in them. In this study, we have studied how fluid flow can affect the adherence of bacterial cells on nanotopographic surfaces. Gram-positive and Gram-negative bacterial species were tested under varying fluid flow rates for their retention and viability after flow exposure. The total number of adherent cells for both species was reduced in the presence of flow, but there was no flowrate dependency. There was a significant reduction in the number of live cells remaining on nanotopographic surfaces with an increasing flowrate for both species. Conversely, we observed a flowrate-independent increase in the number of adherent dead cells. Our results indicated that the presence of flow differentially affected the adherent live and dead bacterial cells on nanotopographic surfaces. This could be because dead bacterial cells were physically pierced by the nano-features, whereas live cells adhered via physiochemical interactions with the surface. Therefore, fluid shear was insufficient to overcome adhesion forces between the surface and dead cells. Furthermore, hydrodynamic forces due to the flow can cause more planktonic and detached live cells to collide with nano-features on the surface, causing more cells to lyse. These results show that nanotopographic surfaces do not have self-cleaning ability as opposed to natural bactericidal nanotopographic surfaces, and nanotopographic surfaces tend to perform better under flow conditions. These findings are highly useful for developing and optimizing nanotopographic surfaces for medical and industrial applications.
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Affiliation(s)
- S. W.
M. A. Ishantha Senevirathne
- Centre
for Biomedical Technologies, Queensland
University of Technology, Brisbane, QLD 4000, Australia
- School
of Mechanical, Medical, and Process Engineering, Faculty of Engineering, Queensland University of Technology, Brisbane 4000 QLD Australia
| | - Yi-Chin Toh
- Centre
for Biomedical Technologies, Queensland
University of Technology, Brisbane, QLD 4000, Australia
- School
of Mechanical, Medical, and Process Engineering, Faculty of Engineering, Queensland University of Technology, Brisbane 4000 QLD Australia
| | - Prasad K. D. V. Yarlagadda
- Centre
for Biomedical Technologies, Queensland
University of Technology, Brisbane, QLD 4000, Australia
- School
of Mechanical, Medical, and Process Engineering, Faculty of Engineering, Queensland University of Technology, Brisbane 4000 QLD Australia
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18
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Wood J, Hayles A, Bright R, Palms D, Vasilev K, Hasan J. Nanomechanical tribological characterisation of nanostructured titanium alloy surfaces using AFM: A friction vs velocity study. Colloids Surf B Biointerfaces 2022; 217:112600. [PMID: 35665641 DOI: 10.1016/j.colsurfb.2022.112600] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 05/06/2022] [Accepted: 05/24/2022] [Indexed: 01/23/2023]
Abstract
Medical-grade titanium alloys used for orthopaedic implants are at risk from infections and complications such as wear and tear. We have recently shown that hydrothermally etched (HTE) nanostructures (NS) formed on the Ti6AlV4 alloy surfaces impart enhanced anti-bacterial activity which results in inhibited formation of bacterial biofilm. Although these titanium alloy nanostructures may resist bacterial colonisation, their frictional properties are yet to be understood. Orthopaedic devices are encapsulated by bone and muscle tissue. Contact friction between orthopaedic implant surfaces and these host tissues may trigger inflammation, osteolysis and wear. To address these challenges, we performed simulation of the contact behaviour between a smooth control Ti6Al4V alloy and HTE surfaces against a hardwearing SiO2 sphere using Atomic Force Microscopy (AFM) in Lateral Force Microscopy mode. The friction study was evaluated in both air and liquid environments at high (5 Hz) and low (0.5 Hz) scan velocities. Lower scan velocities demonstrated opposing friction force changes between the two mediums, with friction stabilising at higher velocities. The friction measured on the NS alloy surfaces was reduced by ~20% in air and ~80% in phosphate buffered saline, in comparison to the smooth control surface, displaying a non-linear behaviour of the force applied by the AFM tip. Changes in friction values and cantilever scan velocities on different substrates are discussed with respect to the Stribeck curve. Reduced friction on nanostructured surfaces may improve wear resistance and aid osseointegration.
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Affiliation(s)
- Jonathan Wood
- Academic Unit of STEM, University of South Australia, Mawson Lakes, Adelaide 5095, South Australia, Australia
| | - Andrew Hayles
- Academic Unit of STEM, University of South Australia, Mawson Lakes, Adelaide 5095, South Australia, Australia
| | - Richard Bright
- Academic Unit of STEM, University of South Australia, Mawson Lakes, Adelaide 5095, South Australia, Australia
| | - Dennis Palms
- Academic Unit of STEM, University of South Australia, Mawson Lakes, Adelaide 5095, South Australia, Australia
| | - Krasimir Vasilev
- Academic Unit of STEM, University of South Australia, Mawson Lakes, Adelaide 5095, South Australia, Australia
| | - Jafar Hasan
- Academic Unit of STEM, University of South Australia, Mawson Lakes, Adelaide 5095, South Australia, Australia.
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