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Wang Y, Teng W, Zhang Z, Ma S, Jin Z, Zhou X, Ye Y, Zhang C, Gou Z, Yu X, Ye Z, Ren Y. Remote Eradication of Bacteria on Orthopedic Implants via Delayed Delivery of Polycaprolactone Stabilized Polyvinylpyrrolidone Iodine. J Funct Biomater 2022; 13:jfb13040195. [PMID: 36278664 PMCID: PMC9589933 DOI: 10.3390/jfb13040195] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 10/08/2022] [Accepted: 10/15/2022] [Indexed: 11/16/2022] Open
Abstract
Bacteria-associated late infection of the orthopedic devices would further lead to the failure of the implantation. However, present ordinary antimicrobial strategies usually deal with early infection but fail to combat the late infection of the implants due to the burst release of the antibiotics. Thus, to fabricate long-term antimicrobial (early antibacterial, late antibacterial) orthopedic implants is essential to address this issue. Herein, we developed a sophisticated MAO-I2-PCLx coating system incorporating an underlying iodine layer and an upper layer of polycaprolactone (PCL)-controlled coating, which could effectively eradicate the late bacterial infection throughout the implantation. Firstly, micro-arc oxidation was used to form a microarray tubular structure on the surface of the implants, laying the foundation for iodine loading and PCL bonding. Secondly, electrophoresis was applied to load iodine in the tubular structure as an efficient bactericidal agent. Finally, the surface-bonded PCL coating acts as a controller to regulate the release of iodine. The hybrid coatings displayed great stability and control release capacity. Excellent antibacterial ability was validated at 30 days post-implantation via in vitro experiments and in vivo rat osteomyelitis model. Expectedly, it can become a promising bench-to-bedside strategy for current infection challenges in the orthopedic field.
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Affiliation(s)
- Yikai Wang
- Department of Orthopedics, Renmin Hospital of Wuhan University, Jiefang Road 238, Wuhan 430060, China
| | - Wangsiyuan Teng
- Department of Orthopedics, Centre for Orthopaedic Research, Orthopedics Research Institute of Zhejiang University, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, China
- Key Laboratory of Motor System Disease Research and Precision Therapy of Zhejiang Province, Hangzhou 310009, China
| | - Zengjie Zhang
- Department of Orthopedics, Centre for Orthopaedic Research, Orthopedics Research Institute of Zhejiang University, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, China
- Key Laboratory of Motor System Disease Research and Precision Therapy of Zhejiang Province, Hangzhou 310009, China
| | - Siyuan Ma
- Department of Orthopedics, Renmin Hospital of Wuhan University, Jiefang Road 238, Wuhan 430060, China
| | - Zhihui Jin
- Department of Orthopedics, Renmin Hospital of Wuhan University, Jiefang Road 238, Wuhan 430060, China
| | - Xingzhi Zhou
- Department of Orthopedics, Centre for Orthopaedic Research, Orthopedics Research Institute of Zhejiang University, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, China
- Key Laboratory of Motor System Disease Research and Precision Therapy of Zhejiang Province, Hangzhou 310009, China
| | - Yuxiao Ye
- School of Material Science and Engineering, University of New South Wales, Sydney 2052, Australia
| | - Chongda Zhang
- New York University Medical Center, New York University, New York, NY 10016, USA
| | - Zhongru Gou
- Bio-Nanomaterials and Regenerative Medicine Research Division, Zhejiang-California International Nanosystem Institute, Zhejiang University, Hangzhou 310058, China
| | - Xiaohua Yu
- Department of Orthopedics, Centre for Orthopaedic Research, Orthopedics Research Institute of Zhejiang University, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, China
- Key Laboratory of Motor System Disease Research and Precision Therapy of Zhejiang Province, Hangzhou 310009, China
| | - Zhaoming Ye
- Department of Orthopedics, Centre for Orthopaedic Research, Orthopedics Research Institute of Zhejiang University, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, China
- Key Laboratory of Motor System Disease Research and Precision Therapy of Zhejiang Province, Hangzhou 310009, China
- Correspondence: (Z.Y.); (Y.R.); Tel.: +86-571-8778-3777 (Z.Y.); +86-027-8804-1911 (ext. 83380) (Y.R.)
| | - Yijun Ren
- Department of Orthopedics, Renmin Hospital of Wuhan University, Jiefang Road 238, Wuhan 430060, China
- Correspondence: (Z.Y.); (Y.R.); Tel.: +86-571-8778-3777 (Z.Y.); +86-027-8804-1911 (ext. 83380) (Y.R.)
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Wishney M, Mahadevan S, Cornwell JA, Savage T, Proschogo N, Darendeliler MA, Zoellner H. Toxicity of Orthodontic Brackets Examined by Single Cell Tracking. TOXICS 2022; 10:460. [PMID: 36006139 PMCID: PMC9413677 DOI: 10.3390/toxics10080460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 07/24/2022] [Accepted: 08/05/2022] [Indexed: 06/15/2023]
Abstract
Subtle toxic effects may be masked in traditional assays that average or summate the response of thousands of cells. We overcome this by using the recent method of single cell tracking in time-lapse recordings. This follows the fate and behavior of individual cells and their progeny and provides unambiguous results for multiple simultaneous biological responses. Further, single cell tracking permits correlation between progeny relationships and cell behavior that is not otherwise possible, including disruption by toxins and toxicants of similarity between paired sister cells. Notably, single cell tracking seems not to have been previously used to study biomaterials toxicity. The culture medium was pre-conditioned by 79 days incubation with orthodontic brackets from seven separate commercial sources. Metal levels were determined by Inductively Coupled Plasma Mass Spectrometry. Metal levels varied amongst conditioned media, with elevated Cr, Mn, Ni, and Cu and often Mo, Pb, Zn, Pd, and Ag were occasionally found. The effect on human dermal fibroblasts was determined by single cell tracking. All bracket-conditioned media reduced cell division (p < 0.05), while some reduced cell migration (p < 0.05). Most bracket-conditioned media increased the rate of asynchronous sister cell division (p < 0.05), a seemingly novel measure for toxicity. No clear effect on cell morphology was seen. We conclude that orthodontic brackets have cytotoxic effects, and that single cell tracking is effective for the study of subtle biomaterials cytotoxicity.
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Affiliation(s)
- Morgan Wishney
- Discipline of Orthodontics, Sydney Dental School, Faculty of Medicine and Health, University of Sydney, Sydney Dental Hospital, Surry Hills, NSW 2010, Australia
| | - Swarna Mahadevan
- The Cellular and Molecular Pathology Research Unit, Oral Pathology and Oral Medicine, Sydney Dental School, Faculty of Medicine and Health, The University of Sydney, Westmead Centre for Oral Health, Westmead Hospital, Westmead, NSW 2145, Australia
| | - James Anthony Cornwell
- The Cellular and Molecular Pathology Research Unit, Oral Pathology and Oral Medicine, Sydney Dental School, Faculty of Medicine and Health, The University of Sydney, Westmead Centre for Oral Health, Westmead Hospital, Westmead, NSW 2145, Australia
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Tom Savage
- School of Geosciences, Faculty of Science, The University of Sydney, Camperdown, NSW 2006, Australia
| | - Nick Proschogo
- School of Chemistry, Faculty of Science, The University of Sydney, Camperdown, NSW 2006, Australia
| | - M. Ali Darendeliler
- Discipline of Orthodontics, Sydney Dental School, Faculty of Medicine and Health, University of Sydney, Sydney Dental Hospital, Surry Hills, NSW 2010, Australia
| | - Hans Zoellner
- The Cellular and Molecular Pathology Research Unit, Oral Pathology and Oral Medicine, Sydney Dental School, Faculty of Medicine and Health, The University of Sydney, Westmead Centre for Oral Health, Westmead Hospital, Westmead, NSW 2145, Australia
- Biomedical Engineering, Faculty of Engineering, The University of Sydney, Camperdown, NSW 2006, Australia
- Graduate School of Biomedical Engineering, University of NSW, Kensington, NSW 2052, Australia
- Strongarch Pty Ltd., Pennant Hills, NSW 2120, Australia
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Lin S, He Y, Tao M, Wang A, Ao Q. Fabrication and evaluation of an optimized xenogenic decellularized costal cartilage graft: preclinical studies of a novel biocompatible prosthesis for rhinoplasty. Regen Biomater 2021; 8:rbab052. [PMID: 34584748 PMCID: PMC8473975 DOI: 10.1093/rb/rbab052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 08/21/2021] [Accepted: 09/02/2021] [Indexed: 12/31/2022] Open
Abstract
On account of the poor biocompatibility of synthetic prosthesis, millions of rhinoplasty recipients have been forced to choose autologous costal cartilage as grafts, which suffer from limited availability, morbidity at the donor site and prolonged operation time. Here, as a promising alternative to autologous costal cartilage, we developed a novel xenogeneic costal cartilage and explored its feasibility as a rhinoplasty graft for the first time. Adopting an improved decellularization protocol, in which the ionic detergent was substituted by trypsin, the resulting decellularized graft was confirmed to preserve more structural components and better mechanics, and eliminate cellular components effectively. The in vitro and in vivo compatibility experiments demonstrated that the decellularized graft showed excellent biocompatibility and biosecurity. Additionally, the functionality assessment of rhinoplasty was performed in a rabbit model, and the condition of grafts after implantation was comprehensively evaluated. The optimized graft exhibited better capacity to reduce the degradation rate and maintain the morphology, in comparison to the decellularized costal cartilage prepared by conventional protocol. These findings indicate that this optimized graft derived from decellularized xenogeneic costal cartilage provides a new prospective for future investigations of rhinoplasty prosthesis and has great potential for clinical application.
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Affiliation(s)
- Shuang Lin
- Department of Plastic Surgery, Shengjing Hospital of China Medical University, 36 Sanhao Street, Shenyang 11004, China.,Department of Tissue Engineering, China Medical University, 77 Puhe Road, Shenyang 110112, China
| | - Yuanjia He
- Department of Stomatology, The Fourth Affiliated Hospital of China Medical University, 4 Chongshan East Road, Shenyang 110033, China
| | - Meihan Tao
- Department of Tissue Engineering, China Medical University, 77 Puhe Road, Shenyang 110112, China
| | - Aijun Wang
- Surgical Bioengineering Laboratory, Department of Surgery, School of Medicine, University of California Davis, Sacramento, CA 95817, USA
| | - Qiang Ao
- Department of Tissue Engineering, China Medical University, 77 Puhe Road, Shenyang 110112, China.,Institute of Regulatory Science for Medical Device, National Engineering Research Center for Biomaterials, Sichuan University, 24 Yihuan Street, Chengdu 610065, China
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Abstract
This study reports the effect of Zn contents on surface morphology, porosity, microstructure and mechanical properties of laser additive manufacturing (LAM) porous ZK61 alloys. The surface morphology and porosity of the LAMed porous ZK61 alloys depend on the laser energy input. With increasing Zn contents, the surface quality of porous Mg-Zn-Zr alloys became worse, the grains are obviously refined and the precipitated phases experienced successive transitions: MgZn → MgZn + Mg7Zn3 → Mg7Zn3. The microhardness was improved significantly and ranged from 57.67 HV to 109.36 HV, which was ascribed to the fine grain strengthening, solid solution strengthening and precipitation strengthening. The LAMed porous Mg-15 wt.% Zn-0.3 wt.% Zr alloy exhibits the highest ultimate compressive strength (73.07 MPa) and elastic modulus (1.785 GPa).
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Wishney M, Savage T, Proschogo N, Petocz P, Darendeliler MA. The metal content of generic orthodontic brackets compared with proprietary brackets. AUSTRALASIAN ORTHODONTIC JOURNAL 2018. [DOI: 10.21307/aoj-2020-067] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Abstract
Background
With minimal manufacturer information, a variety of ‘generic’ orthodontic brackets are available online from overseas distributors. The present study investigated the metal composition of generic orthodontic brackets compared with two well-known ‘proprietary’ brands.
Materials and methods
Ranging in price from AU$2.99 to $65, five sets of different generic brackets were obtained directly from China via eBay (G1, G2…G5). Proprietary brackets were obtained from American Orthodontics (P1) and Rocky Mountain Orthodontics (P2). The 11, 12, 13 and 14 brackets from each set were liquefied in an acid solution and subjected to trace element analysis using inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectroscopy (ICP-OES) with respect to nickel, chromium, iron, copper, molybdenum, manganese, cadmium, mercury, arsenic and lead. Statistical analysis investigated the compositional consistency within and between each brand.
Results
The composition of P1 and P2 agreed with the manufacturer’s data. The generic groups typically had low molybdenum and higher copper content and approximated either 17-4 or AISI304 stainless steels or a combination of both. No relationship between brand and consistency of manufacture could be identified. The cheapest bracket contained lead.
Conclusions
Generic and proprietary brackets showed differences in their metal composition that may have biocompatibility implications.
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Affiliation(s)
- Morgan Wishney
- * Discipline of Orthodontics , Faculty of Dentistry , University of Sydney , Sydney , Australia
- † Dental Hospital , Sydney South West Area Health Service , Sydney , Australia
| | - Tom Savage
- + School of Geoscience , The University of Sydney , Sydney , Australia
| | | | - Peter Petocz
- ‡ Department of Statistics , Macquarie University , Sydney , Australia
| | - M. Ali Darendeliler
- * Discipline of Orthodontics , Faculty of Dentistry , University of Sydney , Sydney , Australia
- † Dental Hospital , Sydney South West Area Health Service , Sydney , Australia
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Portan DV, Deligianni DD, Deligianni K, Kroustalli AA, Tyllianakis M, Papanicolaou GC. Modeling of the interaction between osteoblasts and biocompatible substrates as a function of adhesion strength. J Biomed Mater Res A 2017; 106:621-628. [PMID: 28986950 DOI: 10.1002/jbm.a.36265] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 08/31/2017] [Accepted: 09/25/2017] [Indexed: 11/11/2022]
Abstract
A goal of current implantology research is to design devices that induce controlled, guided, and rapid healing. Nanoscale structured substrates [e.g., titania nanotubes (TNTs) or carbon nanotubes (CNTs)] dramatically improve the functions of conventional biomaterials. The present investigation evaluated the behavior of osteoblasts cells cultured on smooth and nanostructured substrates, by measuring osteoblasts specific biomarkers [alkaline phosphatase (AP) and total protein] and cells adhesion strength to substrates, followed by semi-empirical modeling to predict the experimental results. Findings were in total agreement with the current state of the art. The proliferation, as well as the AP and total protein levels were higher on the nanostructure phases (TNTs, CNTs) comparing to the smooth ones (plastic and pure titanium). Cells adhesion strength measured was found higher on the nanostructured materials. This coincided with a higher value of proteins which are directly implicated in the process of adherence. Results were accurately predicted through the Viscoelastic Hybrid Interphase Model. A gradual adherence of bone cells to implants using multilayered biomaterials that involve biodegradable polymeric films and a nanoscale modification of titanium surface is suggested to improve performance through an interphase-mediated osteointegration of orthopedic implants. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 621-628, 2018.
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Affiliation(s)
- D V Portan
- Composite Materials Group, Department of Mechanical and Aeronautical Engineering, University of Patras, Patras, GR 265 00, Greece
| | - D D Deligianni
- Laboratory of Biomechanics and Biomedical Engineering, Department of Mechanical Engineering and Aeronautics, University of Patras, Rion, 26500, Greece
| | - K Deligianni
- Composite Materials Group, Department of Mechanical and Aeronautical Engineering, University of Patras, Patras, GR 265 00, Greece
| | - A A Kroustalli
- Laboratory of Biomechanics and Biomedical Engineering, Department of Mechanical Engineering and Aeronautics, University of Patras, Rion, 26500, Greece
| | - M Tyllianakis
- Department of Shoulder and Elbow Surgery, University Hospital of Patras, Rio, Greece
| | - G C Papanicolaou
- Composite Materials Group, Department of Mechanical and Aeronautical Engineering, University of Patras, Patras, GR 265 00, Greece
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7
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Cytotoxic outcomes of orthodontic bands with and without silver solder in different cell lineages. Am J Orthod Dentofacial Orthop 2017; 151:957-963. [DOI: 10.1016/j.ajodo.2016.10.030] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 10/01/2016] [Accepted: 10/01/2016] [Indexed: 11/18/2022]
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8
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Grillo CA, Alvarez F, Fernández Lorenzo de Mele MA. Degradation of bioabsorbable Mg-based alloys: Assessment of the effects of insoluble corrosion products and joint effects of alloying components on mammalian cells. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2016; 58:372-80. [DOI: 10.1016/j.msec.2015.08.043] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 07/16/2015] [Accepted: 08/22/2015] [Indexed: 02/06/2023]
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Song YH, Kim MK, Park EJ, Song HJ, Anusavice KJ, Park YJ. Cytotoxicity of alloying elements and experimental titanium alloys by WST-1 and agar overlay tests. Dent Mater 2014; 30:977-83. [PMID: 24946979 DOI: 10.1016/j.dental.2014.05.012] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Revised: 04/10/2014] [Accepted: 05/21/2014] [Indexed: 11/30/2022]
Abstract
OBJECTIVE This study was performed to evaluate the biocompatibility of nine types of pure metals using 36 experimental prosthetic titanium-based alloys containing 5, 10, 15, and 20wt% of each substituted metal. METHODS The cell viabilities for pure metals on Ti alloys that contain these elements were compared with that of commercially pure (CP) Ti using the WST-1 test and agar overlay test. RESULTS The ranking of pure metal cytotoxicity from most potent to least potent was: Co>Cu>In>Ag>Cr>Sn>Au>Pd>Pt>CP Ti. The cell viability ratios for pure Co, Cu, In, and Ag were 13.9±4.6%, 21.7±10.4%, 24.1±5.7%, and 24.8±6.0%, respectively, which were significantly lower than that for the control group (p<0.05). Pure Pd and Pt demonstrated good biocompatibility with cell viabilities of 93.8±9.6% and 97.2±7.1%, respectively. The Ti-5Pd alloy exhibited the highest cell viability (128.4±21.4%), which was greater than that of CP Ti. By alloying pure Co or Cu with Ti, the cell viabilities for the Ti-xCo and Ti-xCu alloys increased significantly up to 10wt% of the alloying element followed by a gradual decrease with a further increase in the concentration of the alloying element. Based on the agar overlay test, pure Ag, Co, Cr, Cu, and In were ranked as 'moderately cytotoxic', whereas all Ti alloys were ranked as 'noncytotoxic'. SIGNIFICANCE The cytotoxicity of pure Ag, Co, Cr, Cu, and In suggests a need for attention in alloy design. The cytotoxicity of alloying elements became more biocompatible when they were alloyed with titanium. However, the cytotoxicity of titanium alloys was observed when the concentration of the alloying element exceeded its respective allowable limit. The results obtained in this study can serve as a guide for the development of new Ti-based alloy systems.
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Affiliation(s)
- Yo-Han Song
- Department of Dental Materials and MRC for Biomineralization Disorders, School of Dentistry, Chonnam National University, Gwangju 500-757, Republic of Korea
| | - Min-Kang Kim
- Department of Dental Materials and MRC for Biomineralization Disorders, School of Dentistry, Chonnam National University, Gwangju 500-757, Republic of Korea
| | - Eun-Jin Park
- Department of Dental Materials and MRC for Biomineralization Disorders, School of Dentistry, Chonnam National University, Gwangju 500-757, Republic of Korea
| | - Ho-Jun Song
- Department of Dental Materials and MRC for Biomineralization Disorders, School of Dentistry, Chonnam National University, Gwangju 500-757, Republic of Korea
| | - Kenneth J Anusavice
- Department of Restorative Dental Sciences, College of Dentistry, University of Florida, Gainesville, FL 32610-0415, USA
| | - Yeong-Joon Park
- Department of Dental Materials and MRC for Biomineralization Disorders, School of Dentistry, Chonnam National University, Gwangju 500-757, Republic of Korea.
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Cellular response to rare earth mixtures (La and Gd) as components of degradable Mg alloys for medical applications. Colloids Surf B Biointerfaces 2014; 117:312-21. [DOI: 10.1016/j.colsurfb.2014.02.030] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 02/18/2014] [Accepted: 02/19/2014] [Indexed: 01/18/2023]
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Zinelis S, Sifakakis I, Katsaros C, Eliades T. Microstructural and mechanical characterization of contemporary lingual orthodontic brackets. Eur J Orthod 2013; 36:389-93. [PMID: 24232131 DOI: 10.1093/ejo/cjt086] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVES To investigate the composition and the microstructural and mechanical characterization of three different types of lingual brackets. MATERIALS AND METHODS Incognito™ (3M Unitek), In-Ovation L (DENTSPLY GAC) and STb™ (Light Lingual System, ORMCO) lingual brackets were studied under the scanning electron microscope employing backscattered electron imaging and their elemental composition was analysed by energy-dispersive X-ray microanalysis. Additionally, Vickers hardness was assessed using a universal hardness-testing machine, and the indentation modulus was measured according to instrumented indentation test. Two-way analysis of variance was conducted employing bracket type and location (base and wing) as discriminating variable. Significant differences among groups were allocated by post hoc Student-Newman-Keuls multiple comparison analysis at 95% level of significance. RESULTS Three different phases were identified for Incognito and In-Ovation L bracket based on mean atomic number contrast. On the contrary, STb did not show mean atomic contrast areas and thus it is recognized as a single phase. Incognito is a one-piece bracket with the same structure in wing and base regions. Incognito consists mainly of noble metals while In-Ovation L and STb show similar formulations of ferrous alloys in wing and base regions. No significant differences were found between ferrous brackets in hardness and modulus values, but there were significant differences between wing and base regions. Incognito illustrated intermediate values with significant differences from base and wing values of ferrous brackets. CONCLUSIONS/IMPLICATIONS Significant differences exist in microstructure, elemental composition, and mechanical properties among the brackets tested; these might have a series of clinical implications during mechanotherapy.
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Affiliation(s)
| | - Iosif Sifakakis
- **Orthodontics, School of Dentistry, National and Kapodistrian University of Athens, Greece
| | - Christos Katsaros
- ***Department of Οrthodontics and Dentofacial Οrthopedics, School of Dentistry, University of Bern and
| | - Theodore Eliades
- ****Department of Orthodontics and Paediatric Dentistry, Centre of Dental Medicine, University of Zurich, Switzerland
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12
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Grillo CA, Morales ML, Mirífico MV, Fernández Lorenzo de Mele MA. Synergistic cytotoxic effects of ions released by zinc–aluminum bronze and the metallic salts on osteoblastic cells. J Biomed Mater Res A 2013; 101:2129-40. [DOI: 10.1002/jbm.a.34503] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Revised: 10/11/2012] [Accepted: 10/17/2012] [Indexed: 11/07/2022]
Affiliation(s)
- Claudia A. Grillo
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA, CCT La Plata‐CONICET), Facultad de Ciencias Exactas, Departamento de Química, Universidad Nacional de La Plata, Casilla de Correo 16, Sucursal 4, 1900 La Plata, Argentina
| | - María L. Morales
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA, CCT La Plata‐CONICET), Facultad de Ciencias Exactas, Departamento de Química, Universidad Nacional de La Plata, Casilla de Correo 16, Sucursal 4, 1900 La Plata, Argentina
| | - María V. Mirífico
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA, CCT La Plata‐CONICET), Facultad de Ciencias Exactas, Departamento de Química, Universidad Nacional de La Plata, Casilla de Correo 16, Sucursal 4, 1900 La Plata, Argentina
- Facultad de Ingeniería, Áreas Departamentales Ingeniería Química y Mecánica, Universidad Nacional de La Plata, Calle 1 esq. 47, 1900 La Plata, Argentina
| | - Mónica A. Fernández Lorenzo de Mele
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA, CCT La Plata‐CONICET), Facultad de Ciencias Exactas, Departamento de Química, Universidad Nacional de La Plata, Casilla de Correo 16, Sucursal 4, 1900 La Plata, Argentina
- Facultad de Ingeniería, Áreas Departamentales Ingeniería Química y Mecánica, Universidad Nacional de La Plata, Calle 1 esq. 47, 1900 La Plata, Argentina
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13
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Martins VJM, Lins RX, Berlinck TCÁ, Fidel RAS. Cytotoxicity of root canal sealers on endothelial cell cultures. Braz Dent J 2013; 24:15-20. [DOI: 10.1590/0103-6440201302090] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Accepted: 12/05/2012] [Indexed: 11/22/2022] Open
Abstract
This study evaluated, in vitro, the cytotoxicity of six root canal sealers after 12, 24 and 72 h of contact time, using an endothelial ECV-304 cell line. The MTT assay was used for analysis of cell viability. Twelve specimens of each sealer were prepared and randomly assigned to 6 groups according to the commercial brands (n=4/time). A control group was also formed, which was not subjected to the contact with sealers. To assess the effects of sealers on endothelial cells, the specimens were placed in culture plate wells and incubated at 37°C with 5% CO2 and 100% humidity. MTT assays were performed in quadruplicate after 12, 24 and 72 h of contact of the sealer specimens with monolayers. Statistical analysis was performed by two-way ANOVA with Bonferroni post-hoc test at a significance level of 5%. Analysis of absorbance in the experimental groups showed that GuttaFlow presented the lowest cytotoxicity, with a mean absorbance of 0.048, followed by Pulp Canal Sealer (0.038), Sealer 26 (0.038), Endo Densell (0.036) and Pulp Fill (0.035). The control group had a mean absorbance of 0.098. Based on the results, Endofill and GuttaFlow were the most and the least cytotoxic sealers, respectively.
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Toledo CEP, Souza MA, Fraga MR, Ribeiro LC, Ferreira AP, Vitral RWF. Cellular viability and nitric oxide (NO) production by J774 macrophages in the presence of orthodontic archwires. ACTA ACUST UNITED AC 2012. [DOI: 10.4236/jbise.2012.55032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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15
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Suárez C, Vilar T, Gil J, Sevilla P. In vitro evaluation of surface topographic changes and nickel release of lingual orthodontic archwires. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2010; 21:675-83. [PMID: 19826928 DOI: 10.1007/s10856-009-3898-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2009] [Accepted: 10/02/2009] [Indexed: 05/17/2023]
Abstract
The objective of the article is to study surface topographic changes and nickel release in lingual orthodontic archwires in vitro. Stainless steel (SS), nickel-titanium (NiTi) and copper-nickel-titanium (CuNiTi) lingual orthodontic archwires were studied using atomic absorption spectrometry for nickel release after immersion in a saline solution. Surface roughness changes were measured using atomic force microscopy. Differences between groups were analyzed using independent sample t-tests. Statistically significant changes in roughness were seen in all archwires except NiTi. Surface changes were most severe in the CuNiTi alloy. SS archwires released the highest amount of nickel. In conclusion, only roughness changes in CuNiTi archwires seemed to be clinically significant. The amount of nickel released for all archwires tested is below the levels known to cause cell damage.
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Affiliation(s)
- Carlos Suárez
- Division d'Orthodontie, Section de Médecine Dentaire, Faculté de Médecine, Université de Genève, Rue Barthélemy-Menn, 19, 1205, Geneva, Switzerland.
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Sima LE, Filimon A, Piticescu RM, Chitanu GC, Suflet DM, Miroiu M, Socol G, Mihailescu IN, Neamtu J, Negroiu G. Specific biofunctional performances of the hydroxyapatite-sodium maleate copolymer hybrid coating nanostructures evaluated by in vitro studies. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2009; 20:2305-2316. [PMID: 19543854 DOI: 10.1007/s10856-009-3800-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2008] [Accepted: 06/04/2009] [Indexed: 05/27/2023]
Abstract
The nanohybrid structures consisting of hydroxyapatite (HA) and sodium maleate-vinyl acetate copolymer (MP) deposited by Matrix Assisted Pulsed Laser Evaporation (MAPLE) technique on Ti surfaces were investigated for specific biological qualities required in bone implantology. The data from in vitro studies demonstrated that human primary osteoblasts (OBs) firmly adhered to Ti coated with HA-MP as indicated by cytoskeleton and vinculin dynamics. OBs spread onto biomaterial surface and formed groups of cells which during their biosynthetic activity expressed OB phenotype specific markers (collagen and non-collagenous proteins) and underwent controlled proliferation.
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Affiliation(s)
- L E Sima
- Institute of Biochemistry, Romanian Academy, Splaiul Independentei 296, Bucharest 060031, Romania
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Hulander M, Hong J, Andersson M, Gervén F, Ohrlander M, Tengvall P, Elwing H. Blood interactions with noble metals: coagulation and immune complement activation. ACS APPLIED MATERIALS & INTERFACES 2009; 1:1053-1062. [PMID: 20355891 DOI: 10.1021/am900028e] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Noble metals are interesting biomaterials for a number of reasons, e.g., their chemical inertness and relative mechanical softness, silver's long known antimicrobial properties, and the low allergenic response shown by gold. Although important for the final outcome of biomaterials, little is reported about early events between pure noble metals and blood. In this article, we used whole blood in the "slide chamber model" to study the activation of the immune complement activation, generation of thrombin/antithrombin (TAT) complexes, and platelet depletion from blood upon contact with silver (Ag), palladium (Pd), gold (Au), titanium (Ti), and Bactiguard, a commercial nanostructured biomaterial coating comprised of Ag, Pd, and Au. The results show the highest TAT generation and platelet depletion on Ti and Au and lower on Pd, Ag, and the Bactiguard coating. The immune complement factor 3 fragment (C3a) was generated by the surfaces in the following order: Ag > Au > Pd > Bactiguard > Ti. Quartz crystal microbalance adsorption studies with human fibrinogen displayed the highest deposition to Ag and the lowest onto the Bactiguard coating. The adsorbed amounts of fibrinogen did not correlate with thrombogenicity in terms of TAT formation and platelet surface accumulation in blood. The combined results suggest, hence, that noble metal chemistry has a different impact on the protein adsorption properties and general blood compatibility. The low thrombogenic response by the Bactiguard coating cannot be explained by any of the single noble metal properties but is likely a successful combination of the nanostructure, nanogalvanic effects, or combinatory chemical and physical materials properties.
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Affiliation(s)
- Mats Hulander
- Department of Cell and Molecular Biology/Interface Biophysics, Gothenburg University, Medicinaregatan 9E, 41390 Gothenburg, Sweden.
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Kuhta M, Pavlin D, Slaj M, Varga S, Lapter-Varga M, Slaj M. Type of archwire and level of acidity: effects on the release of metal ions from orthodontic appliances. Angle Orthod 2009; 79:102-10. [PMID: 19123703 DOI: 10.2319/083007-401.1] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2007] [Accepted: 02/01/2008] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVE To examine the effects of three different parameters-pH value, type of archwire, and length of immersion-on release of metal ions from orthodontic appliances. MATERIALS AND METHODS Simulated fixed orthodontic appliances that corresponded to one-half of the maxillary arch were immersed in artificial saliva of different pH values (6.75 +/- 0.15 and 3.5 +/- 0.15) during a 28-day period. Three types of archwires were used: stainless steel (SS), nickel-titanium (NiTi), and thermo NiTi. The quantity of metal ions was determined with the use of a high-resolution mass spectrophotometer (HR-ICP/MS). RESULTS The release of six different metal ions was observed: titanium (Ti), chromium (Cr), nickel (Ni), iron (Fe), copper (Cu), and zinc (Zn). Repeated measures statistical analysis of variance (ANOVA) was used. Results showed that (1) the appliances released measurable quantities of all ions examined; (2) the change in pH had a very strong effect (up to 100-fold) on the release of ions; and (3) the release of ions was dependent on wire composition, but it was not proportional to the content of metal in the wire. The largest number of ions was released during the first week of appliance immersion. CONCLUSION Levels of released ions are sufficient to cause delayed allergic reactions. This must be taken into account when type of archwire is selected, especially in patients with hypersensitivity or compromised oral hygiene.
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Affiliation(s)
- Maja Kuhta
- Department of Orthodontics, University Health Science Center, San Antonio, Texas, USA
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19
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Lefaix H, Asselin A, Vermaut P, Sautier JM, Berdal A, Portier R, Prima F. On the biocompatibility of a novel Ti-based amorphous composite: structural characterization and in-vitro osteoblasts response. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2008; 19:1861-9. [PMID: 17914625 DOI: 10.1007/s10856-007-3248-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2007] [Accepted: 07/26/2007] [Indexed: 05/17/2023]
Abstract
Titanium and its alloys are frequently used as dental and orthopaedic implants due to their high mechanical strength, low elastic modulus and biocompatibility. However, as these materials have a poor wear resistance, tribo-chemical reactions during use produce debris accumulation, resulting in adverse cellular responses. In that sense, amorphous based materials are potential candidates, considering their hardness and crack growth resistance. This paper reports on the structural characterization of the as-quenched Ti45Zr38Ni17 alloy. This system displays a duplex structure never mentioned before with a low dispersion of nanometric beta-phase particles in an amorphous matrix. Moreover, in order to explore the biocompatibility of such composite, primary osteoblasts cultures are used to analyse cell behaviour around and upon the metallic surface. Osteoblasts attach and proliferate on the material as demonstrated by scanning electron microscopy. Cell proliferation and bone nodule formation are also observed in cultures with Ti45Zr38Ni17 particles by phase contrast microscope. In addition, transmission electron microscopy reveals ultrastructural features very close to those observed in vivo during intramembranous ossification with active osteoblasts surrounded by an extracellular matrix and a mineralized one. In conclusion, these results demonstrate that osteoblasts, cultured in presence of Ti45Zr38Ni17 alloy, proliferate, differentiate and synthesize bone matrix.
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Affiliation(s)
- H Lefaix
- Laboratoire de Physico-Chimie des Surfaces, CNRS-ENSCP (UMR 7045), Ecole Nationale Supérieure de Chimie de Paris, 11 rue Pierre et Marie Curie, Paris cedex 05, 75231, France.
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Relationship between radial diffusion of copper ions released from a metal disk and cytotoxic effects. Comparison with results obtained using extracts. Bioelectrochemistry 2007; 72:94-101. [PMID: 18191620 DOI: 10.1016/j.bioelechem.2007.11.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2007] [Revised: 08/16/2007] [Accepted: 11/18/2007] [Indexed: 11/22/2022]
Abstract
The extended use of metallic biomaterials yields to increasing sources of metal ions within the human body and may result in inflammation of the surrounding tissues, cell damage, and cancer. The aim of this study was to investigate the relationship between the radial diffusion of metal ions released from a metal disk by the corrosion process and the toxic effect on a cell line that grew around it. Results obtained with the metal disks (direct contact) were compared with assays made with extracts obtained from the dissolution of a metallic sample ex situ and then added to the cell culture to elucidate the cause of apparent inconsistencies in previous reports. The change of copper concentration due to corrosion and transient diffusion of copper ions from the copper disks into the cell line was evaluated according to Fick's 2nd law. Surviving cells distribution was interpreted considering the radial and time-dependence of copper concentration. We concluded that the toxic effect on those cells close to metallic biomaterials may be underestimated when only the extract methodology is employed for cytotoxic tests or when during the experiments with disks the presence of concentration gradients and the non-homogeneous distribution of dead cells are disregarded.
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Podsiadlo P, Paternel S, Rouillard JM, Zhang Z, Lee J, Lee JW, Gulari E, Kotov NA. Layer-by-layer assembly of nacre-like nanostructured composites with antimicrobial properties. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:11915-21. [PMID: 16316133 DOI: 10.1021/la051284+] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
In a recent report, we have presented the layer-by-layer (LBL) assembly of a biomimetic nanostructured composite from Na(+)-montmorillonite clay nanosheets and poly(diallylmethylammonium chloride) (Tang, Z.; Kotov, N.; Magonov, S.; Ozturk, B. Nat. Mater. 2003, 2, 413). The structure, deformation mechanism, and mechanical properties of the material are very similar to those of natural nacre and lamellar bones. This fact prompts further investigation of these composites as potential bone implants. LBL assembly affords preparation of multifunctional composites, and here we demonstrate that not only mechanical strength, but also antibacterial activity, can be introduced in these implantable materials by alternating clay layers with starch-stabilized silver nanoparticles. The resulting composite showed excellent structural stability with no detectable levels of silver lost over a 1 month period. Evaluation of the antibacterial properties showed almost complete growth inhibition of E. coli over an 18 h period. The amount of silver eluted from the LBL composite over a 1 month period was determined to be only 0.5-3.0 microg/L. This concentration of silver did not prevent the growth of the mammalian tissue cultures. The LBL composite has shown biocompatibility with the human osteoblast cell line.
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Affiliation(s)
- Paul Podsiadlo
- Department of Chemical Engineering, The University of Michigan, Ann Arbor, 48109, USA
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Wirth C, Comte V, Lagneau C, Exbrayat P, Lissac M, Jaffrezic-Renault N, Ponsonnet L. Nitinol surface roughness modulates in vitro cell response: a comparison between fibroblasts and osteoblasts. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2005. [DOI: 10.1016/j.msec.2004.06.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Pancrazio JJ, Gray SA, Shubin YS, Kulagina N, Cuttino DS, Shaffer KM, Eisemann K, Curran A, Zim B, Gross GW, O'Shaughnessy TJ. A portable microelectrode array recording system incorporating cultured neuronal networks for neurotoxin detection. Biosens Bioelectron 2003; 18:1339-47. [PMID: 12896834 DOI: 10.1016/s0956-5663(03)00092-7] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Cultured neuronal networks, which have the capacity to respond to a wide range of neuroactive compounds, have been suggested to be useful for both screening known analytes and unknown compounds for acute neuropharmacologic effects. Extracellular recording from cultured neuronal networks provides a means for extracting physiologically relevant activity, i.e. action potential firing, in a noninvasive manner conducive for long-term measurements. Previous work from our laboratory described prototype portable systems capable of high signal-to-noise extracellular recordings from cardiac myocytes. The present work describes a portable system tailored to monitoring neuronal extracellular potentials that readily incorporates standardized microelectrode arrays developed by and in use at the University of North Texas. This system utilizes low noise amplifier and filter boards, a two-stage thermal control system with integrated fluidics and a graphical user interface for data acquisition and control implemented on a personal computer. Wherever possible, off-the-shelf components have been utilized for system design and fabrication. During use with cultured neuronal networks, the system typically exhibits input referred noise levels of only 4-6 microVRMS, such that extracellular potentials exceeding 40 microV can be readily resolved. A flow rate of up to 1 ml/min was achieved while the cell recording chamber temperature was maintained within a range of 36-37 degrees C. To demonstrate the capability of this system to resolve small extracellular potentials, pharmacological experiments with cultured neuronal networks have been performed using ion channel blockers, tetrodotoxin and tityustoxin. The implications of the experiments for neurotoxin detection are discussed.
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Affiliation(s)
- Joseph J Pancrazio
- Center for Bio/Molecular Science and Engineering, Code 6900, Naval Research Laboratory, Washington, DC 20375, USA.
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Schmidt C, Kaspar D, Sarkar MR, Claes LE, Ignatius AA. A scanning electron microscopy study of human osteoblast morphology on five orthopedic metals. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 2003; 63:252-61. [PMID: 12115756 DOI: 10.1002/jbm.10185] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Despite the long-standing use of metals as orthopedic implants there still are unsolved problems with these materials and open questions about their behavior in a biological environment. Cell-culture studies provide a useful tool for investigations. In addition to the determination of biochemical or molecular biological parameters, the morphology of adhering cells reflects their interaction with the substrata. This article describes an investigation of the morphology of human osteoblasts on stainless steel, cobalt chromium alloy, commercially pure titanium, Ti-6Al-4V, and Ti-6Al-7Nb with surface designs similar to those used as clinical implants. A cell culture plastic surface was used as a control material. The materials were examined by scanning electron microscopy at different points of time. The cells spread, proliferated, and formed nodules on all test substrates in a time-dependent manner, without signs of a disturbing influence from any of the materials. On the smooth surfaces the cells showed a flattened fibroblast-like morphology and only slight differences could be detected. Therefore, the cellular morphology seems not to be markedly affected by the different chemical material compositions. In contrast, the titanium alloy with a rough, sandblasted surface induced a three-dimensional growth. This three-dimensional cellular network could be the basis for the known earlier differentiation of osteoblasts on rough surfaces in vitro and a better osseointegration in vivo.
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Affiliation(s)
- Carla Schmidt
- Institute of Orthopaedic Research and Biomechanics, University of Ulm, Germany.
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Fathi MH, Salehi M, Saatchi A, Mortazavi V, Moosavi SB. In vitro corrosion behavior of bioceramic, metallic, and bioceramic-metallic coated stainless steel dental implants. Dent Mater 2003; 19:188-98. [PMID: 12628430 DOI: 10.1016/s0109-5641(02)00029-5] [Citation(s) in RCA: 152] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVES The most common metals and alloys used in dentistry may be exposed to a process of corrosion in vivo that make them cytotoxic. The biocompatibility of dental alloys is primarily related to their corrosion behavior. The aim of this work was to evaluate the corrosion behavior and thus the biocompatibility of the uncoated and coated stainless steels and compare the effect of type of coatings on corrosion behavior. METHODS Three types of coatings, hydroxyapatite (HA), titanium (Ti), and a double-layer HA/Ti on AISI 316L stainless steel were made. HA coating was produced using plasma-spraying technique and Ti coating was made using physical vapor deposition process. In order to perform a novel double-layer composite coating, a top layer of HA was plasma-sprayed over a physical vapor deposited Ti layer on AISI 316L stainless steel. Structural characterization techniques including XRD, SEM and EDX were used to investigate the microstructure, morphology and crystallinity of the coatings. Electrochemical potentiodynamic tests were performed in physiological solutions in order to determine and compare the corrosion behavior of the coated and uncoated specimens as an indication of biocompatibility. RESULTS Double-layer HA/Ti coating on AISI 316L SS had a positive effect on improvement of corrosion behavior. The decrease in corrosion current densities was significant for these coated specimens and was much lower than the values obtained for uncoated and single HA coated specimens. Ti coating on AISI 316L SS also has a beneficial effect on corrosion behavior. The results were compared with the results of corrosion behavior of HA coated commercially pure titanium (cpTi) and uncoated cpTi. SIGNIFICANCE These results demonstrated that the double-layer HA/Ti coated 316L SS can be used as an endodontic implant and two goals including improvement of corrosion resistance and bone osteointegration can be obtained simultaneously.
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Affiliation(s)
- M H Fathi
- Department of Materials Engineering, Isfahan University of Technology, 84154, Isfahan, Iran.
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26
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Noda M, Wataha JC, Lockwood PE, Volkmann KR, Kaga M, Sano H. Low-dose, long-term exposures of dental material components alter human monocyte metabolism. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 2002; 62:237-43. [PMID: 12209944 DOI: 10.1002/jbm.10065] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The short-term degradation of dental polymers and alloys in biological environments has been well documented, but recent evidence indicates that oral tissues may be chronically exposed to low levels of these released components. The effect of these chronic exposures on the ability of cells to respond to a subsequent challenge is not known. To investigate this idea, we exposed human THP-1 monocytes to sublethal concentrations of HEMA, TEGDMA, Hg(2+), and Ni(2+) for 2 weeks and then assessed the monocytic response to subsequent 24-h challenge with the same components at higher concentrations. Chronic (2 week) exposures of monocytes to HEMA and both metal ions significantly altered monocyte response to short-term (24 h) secondary exposures, even when overt effects of the chronic exposures were not apparent. However, cellular responses were highly variable depending on the material and its concentrations. For TEGDMA, no effects were seen. These results demonstrate that the chronic effects of materials must be considered even when the chronic exposure has no initial overt effect. The effect on cells may only be apparent if the cell is challenged by a secondary exposure.
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Affiliation(s)
- M Noda
- Department of Oral Health Sciences, Graduate School of Dental Medicine, Hokkaido University, North 13, West 7, Sapporo, 060-8586, Japan.
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Murnane AC, Brown K, Keith CH. Preferential initiation of PC12 neurites in directions of changing substrate adhesivity. J Neurosci Res 2002; 67:321-8. [PMID: 11813236 DOI: 10.1002/jnr.10130] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
When PC12 cells are grown on substrates showing a gradient of nonspecific adhesion, they preferentially initiate neurites in directions of changing adhesivity, whether that change is in the direction of increasing or decreasing adhesivity. This preference for changing adhesivity is ablated both by C. difficile toxin A, which inhibits all Rho-family GTPases, and by C. botulinum C3 exoenzyme, which specifically inhibits Rho.
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Affiliation(s)
- Aeneas C Murnane
- Department of Cellular Biology, University of Georgia, Athens, Georgia 30602, USA
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