1
|
Functionalized Self-Assembled Monolayers: Versatile Strategies to Combat Bacterial Biofilm Formation. Pharmaceutics 2022; 14:pharmaceutics14081613. [PMID: 36015238 PMCID: PMC9415113 DOI: 10.3390/pharmaceutics14081613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/29/2022] [Accepted: 07/30/2022] [Indexed: 11/16/2022] Open
Abstract
Bacterial infections due to biofilms account for up to 80% of bacterial infections in humans. With the increased use of antibiotic treatments, indwelling medical devices, disinfectants, and longer hospital stays, antibiotic resistant infections are sharply increasing. Annual deaths are predicted to outpace cancer and diabetes combined by 2050. In the past two decades, both chemical and physical strategies have arisen to combat biofilm formation on surfaces. One such promising chemical strategy is the formation of a self-assembled monolayer (SAM), due to its small layer thickness, strong covalent bonds, typically facile synthesis, and versatility. With the goal of combating biofilm formation, the SAM could be used to tether an antibacterial agent such as a small-molecule antibiotic, nanoparticle, peptide, or polymer to the surface, and limit the agent’s release into its environment. This review focuses on the use of SAMs to inhibit biofilm formation, both on their own and by covalent grafting of a biocidal agent, with the potential to be used in indwelling medical devices. We conclude with our perspectives on ongoing challenges and future directions for this field.
Collapse
|
2
|
Combining microscopy assays of bacteria-surface interactions to better evaluate antimicrobial polymer coatings. Appl Environ Microbiol 2022; 88:e0224121. [PMID: 35108075 DOI: 10.1128/aem.02241-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Validation of the antimicrobial performance of contact-killing polymer surfaces through experimental determination of bacterial adhesion or viability is essential for their targeted development and application. However, there is not yet a consensus on a single most appropriate evaluation method or procedure. Combining and benchmarking previously reported assays could reduce the significant variation and misinterpretation of efficacy data obtained from different methods. In this work, we systematically investigated the response of bacteria cells to anti-adhesive and antiseptic polymer coatings by combining (i) bulk solution-based, (ii) thin-film spacer-based and (iii) direct contact assays. In addition, we evaluated the studied assays using a five-point scoring framework that highlights key areas for improvement. Our data suggest that combined microscopy assays provide a more comprehensive representation of antimicrobial performance, thereby helping to identify effective types of antibacterial polymer coatings. Importance We present and evaluate a combination of methods for validating the efficacy of antimicrobial surfaces. Antimicrobial surfaces/coatings based on contact-killing components can be instrumental to functionalise a wide range of products. However, there is not yet a consensus on a single, most appropriate method to evaluate their performance. By combining three microscopy methods, we were able to discern contact killing effects at the single cell level that were not detectable by conventional bulk microbiological analyses. The developed approach is considered advantageous for the future targeted development of robust and sustainable antimicrobial surfaces.
Collapse
|
3
|
Zhou W, Wang X, Li Z, Zhao H, Weir MD, Cheng L, Xu HHK, Huang X. Novel dual-functional implants via oxygen non-thermal plasma and quaternary ammonium to promote osteogenesis and combat infections. Dent Mater 2021; 38:169-182. [PMID: 34924200 DOI: 10.1016/j.dental.2021.12.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 11/08/2021] [Accepted: 12/02/2021] [Indexed: 02/05/2023]
Abstract
OBJECTIVE Implant-related infections are a primary reason for implant failures that affect millions of patients. It is of paramount importance to develop novel implants that possess the dual functions of osteogenesis-promotion and antibacterial activity. The objectives of this study were to: (1) develop novel dual-functional titanium (Ti) implants by combining oxygen non-thermal plasma and covalent bonding of antibacterial organosilicon quaternary ammonium monomers; (2) investigate the physicochemical properties, bioactivity and antibacterial effects of the modified implants for the first time. METHODS Surface characteristics of the modified Ti surfaces were tested. Adherence and viability of rat bone marrow-derived stem cells (rBMSCs) on the surface were evaluated. Metabolic activity of biofilm on the surfaces were measured. The stability of the dual-function after 5000 thermal cycles was also evaluated. RESULTS The presence of chemical bonding between Ti and organosilicon monomers demonstrated covalent immobilization of the antibacterial agents. The water contact angle of the treated Ti surfaces decreased from 70.98 ± 3.68° to 59.86 ± 4.91°. The adhesion and proliferation of rBMSCs on the modified Ti were increased by 40%, compared to control group (P < 0.05). The metabolic level of biofilms on modified Ti were reduced by more than half, compared to control (P < 0.05). The modified Ti implants exhibited cell-promotion and antibacterial stability after thermal cycles. SIGNIFICANCE The new dual-functional Ti implant is promising to promote osteogenesis while simultaneously preventing infections. Furthermore, the novel surface modification and processing methods have applicability to enhancing a wide range of other implants to improve bioactivity and combat infections.
Collapse
Affiliation(s)
- Wen Zhou
- Postdoctoral workstation & Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Lab of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, Fuzhou 350002, China; Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, MD, 21201, USA; State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, National Clinical Research Center for Oral Diseases & Department of Operative Dentistry and Endodontics, West China School of Stomatology, Sichuan University, Chengdu 610041, China
| | - Xianlong Wang
- Department of Bioinformatics, Fujian Key Laboratory of Medical Bioinformatics, Key Laboratory of Ministry of Education for Gastrointestinal Cancer, Fujian Medical University, Fuzhou, 350122 Fujian, China
| | - Zhen Li
- Postdoctoral workstation & Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Lab of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, Fuzhou 350002, China
| | - Hongyan Zhao
- Postdoctoral workstation & Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Lab of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, Fuzhou 350002, China
| | - Michael D Weir
- Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, MD, 21201, USA
| | - Lei Cheng
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, National Clinical Research Center for Oral Diseases & Department of Operative Dentistry and Endodontics, West China School of Stomatology, Sichuan University, Chengdu 610041, China.
| | - Hockin H K Xu
- Department of Advanced Oral Sciences and Therapeutics, University of Maryland School of Dentistry, Baltimore, MD, 21201, USA.
| | - Xiaojing Huang
- Postdoctoral workstation & Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Lab of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, Fuzhou 350002, China.
| |
Collapse
|
4
|
Kim YJ, Kim JB, Song CS, Nahm SS. Disinfection of various materials with 3-(trimethoxysilyl)-propyldimethyloctadecyl am-monium chloride in hatchery facilities. Anim Biosci 2021; 35:631-637. [PMID: 34696574 PMCID: PMC8902209 DOI: 10.5713/ab.21.0302] [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: 06/29/2021] [Accepted: 09/07/2021] [Indexed: 11/27/2022] Open
Abstract
Objective Surface disinfection is important in the proper running of livestock farms. However, disinfection of farm equipment and facilities is difficult because they are made of different materials, besides having large surface areas and complex structures. 3-(trimethoxysilyl)-propyldimethyloctadecyl ammonium chloride (Si-QAC) is a quaternary ammonium salt-based disinfectant that attaches to various surfaces by forming covalent bonds and maintains its disinfecting capacity for a considerable time. Our aim was to evaluate the potential use of Si-QAC for disinfection of farm equipment and facilities. Methods The short- and long-term antimicrobial and antiviral effects of Si-QAC were evaluated in both laboratory and farm settings using modified quantitative assessment method based on the standard operating procedures of the United States Environmental Protection Agency. Results Si-QAC was highly effective in controlling the growth of the Newcastle disease virus and avian pathogenic Escherichia coli. Electron microscopy revealed that the mechanism underlying the disinfection activity of Si-QAC was associated with its ability to damage the outer membrane of the pathogen cells. In the field test, Si-QAC effectively reduced viral contamination of surfaces of equipment and space. Conclusion Our results suggest that Si-QAC has great potential as an effective chemical for disinfecting farm equipment and facilities. This disinfectant could retain its disinfection ability longer than other commercial disinfectants and contribute to better farm biosecurity.
Collapse
Affiliation(s)
- Yu-Jin Kim
- College of Veterinary Medicine, Konkuk University, Seoul 05029, Korea
| | | | - Chang-Seon Song
- College of Veterinary Medicine, Konkuk University, Seoul 05029, Korea.,KCAV Co., Ltd., Seoul 05029, Korea
| | - Sang-Soep Nahm
- College of Veterinary Medicine, Konkuk University, Seoul 05029, Korea
| |
Collapse
|
5
|
Abstract
Biomedical devices have become essential in the health care. Every day, an enormous number of these devices are used or implanted in humans. In this context, the bacterial contamination that could be developed in implanted devices is critical since it is estimated that infections kill more people than other medical causes. Commonly, these infections are treated with antibiotics, but the biofilm formation on implant surfaces could significantly reduce the effectiveness of these antibiotics since bacteria inside the biofilm is protected from the drug. In some cases, a complete removal of the implant is necessary in order to overcome the infection. In this context, antibacterial coatings are considered an excellent strategy to avoid biofilm formation and, therefore, mitigate the derived complications. In this review, the main biomaterials used in biomedical devices, the mechanism of biofilm formation, and the main strategies for the development of antibacterial coatings, are reviewed. Finally, the main polymer-based strategies to develop antibacterial coatings are summarized, with the aim of these coatings being to avoid the bacteria proliferation by controlling the antibacterial mechanisms involved and enhancing long-term stability.
Collapse
|
6
|
Elena P, Miri K. Formation of contact active antimicrobial surfaces by covalent grafting of quaternary ammonium compounds. Colloids Surf B Biointerfaces 2018; 169:195-205. [DOI: 10.1016/j.colsurfb.2018.04.065] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 04/24/2018] [Accepted: 04/29/2018] [Indexed: 12/13/2022]
|
7
|
Yu Q, Wu Z, Chen H. Dual-function antibacterial surfaces for biomedical applications. Acta Biomater 2015; 16:1-13. [PMID: 25637065 DOI: 10.1016/j.actbio.2015.01.018] [Citation(s) in RCA: 245] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2014] [Revised: 12/24/2014] [Accepted: 01/16/2015] [Indexed: 12/12/2022]
Abstract
Bacterial attachment and the subsequent formation of biofilm on surfaces of synthetic materials pose a serious problem in both human healthcare and industrial applications. In recent decades, considerable attention has been paid to developing antibacterial surfaces to reduce the extent of initial bacterial attachment and thereby to prevent subsequent biofilm formation. Briefly, there are three main types of antibacterial surfaces: bactericidal surfaces, bacteria-resistant surfaces, and bacteria-release surfaces. The strategy adopted to develop each type of surface has inherent advantages and disadvantages; many efforts have been focused on the development of novel antibacterial surfaces with dual functionality. In this review, we highlight the recent progress made in the development of dual-function antibacterial surfaces for biomedical applications. These surfaces are based on the combination of two strategies into one system, which can kill attached bacteria as well as resisting or releasing bacteria. Perspectives on future research directions for the design of dual-function antibacterial surfaces are also provided.
Collapse
|
8
|
Porosa LM, Mistry KB, Mocella A, Deng H, Hamzehi S, Caschera A, Lough AJ, Wolfaardt G, Foucher DA. Synthesis, structures and properties of self-assembling quaternary ammonium dansyl fluorescent tags for porous and non-porous surfaces. J Mater Chem B 2014; 2:1509-1520. [DOI: 10.1039/c3tb21633k] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Surface grafted silane, phosphate and benzophenone dansyl molecules.
Collapse
Affiliation(s)
- Lukasz M. Porosa
- Department of Chemistry and Biology
- Ryerson University
- Toronto, Canada M5B-2K3
| | - Kamlesh B. Mistry
- Department of Chemistry and Biology
- Ryerson University
- Toronto, Canada M5B-2K3
| | - Amanda Mocella
- Department of Chemistry and Biology
- Ryerson University
- Toronto, Canada M5B-2K3
| | - Hellen Deng
- Department of Chemistry and Biology
- Ryerson University
- Toronto, Canada M5B-2K3
| | - Shayan Hamzehi
- Department of Chemistry and Biology
- Ryerson University
- Toronto, Canada M5B-2K3
| | - Alex Caschera
- Department of Chemistry and Biology
- Ryerson University
- Toronto, Canada M5B-2K3
| | - Alan J. Lough
- Department of Chemistry
- University of Toronto
- Toronto, Canada
| | - Gideon Wolfaardt
- Department of Chemistry and Biology
- Ryerson University
- Toronto, Canada M5B-2K3
| | - Daniel A. Foucher
- Department of Chemistry and Biology
- Ryerson University
- Toronto, Canada M5B-2K3
| |
Collapse
|
9
|
Coad BR, Kidd SE, Ellis DH, Griesser HJ. Biomaterials surfaces capable of resisting fungal attachment and biofilm formation. Biotechnol Adv 2013; 32:296-307. [PMID: 24211473 DOI: 10.1016/j.biotechadv.2013.10.015] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 10/10/2013] [Accepted: 10/29/2013] [Indexed: 10/26/2022]
Abstract
Microbial attachment onto biomedical devices and implants leads to biofilm formation and infection; such biofilms can be bacterial, fungal, or mixed. In the past 15 years, there has been an increasing research effort into antimicrobial surfaces but the great majority of these publications present research on bacteria, with some reports also testing resistance to fungi. Very few studies have focused exclusively on antifungal surfaces. However, with increasing recognition of the importance of fungal infections to human health, particularly related to infections at biomaterials, it would seem that the interest in antifungal surfaces is disproportionately low. In studies of both bacteria and fungi, fungi tend to be the minor focus with hypothesized antibacterial mechanisms of action often generalized to also explain the antifungal effect. Yet bacteria and fungi represent two Distinct biological Domains and possess substantially different cellular physiology and structure. Thus it is questionable whether these generalizations are valid. Here we review the scientific literature focusing on surface coatings prepared with antifungal agents covalently attached to the biomaterial surface. We present a critical analysis of generalizations and their evidence. This review should be of interest to researchers of "antimicrobial" surfaces by addressing specific issues that are key to designing and understanding antifungal biomaterials surfaces and their putative mechanisms of action.
Collapse
Affiliation(s)
- Bryan R Coad
- The Ian Wark Research Institute, University of South Australia, Mawson Lakes, SA 5095, Australia.
| | - Sarah E Kidd
- National Mycology Reference Centre, SA Pathology at the Women's and Children's Hospital, North Adelaide, SA 5006, Australia; School of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA 5005, Australia
| | - David H Ellis
- School of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA 5005, Australia
| | - Hans J Griesser
- The Mawson Institute, University of South Australia, Mawson Lakes, SA 5095, Australia
| |
Collapse
|
10
|
Lafarge J, Kébir N, Schapman D, Burel F. Design of self-disinfecting PVC surfaces using the click chemistry. REACT FUNCT POLYM 2013. [DOI: 10.1016/j.reactfunctpolym.2013.08.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
|
11
|
Gong SQ, Epasinghe DJ, Zhou B, Niu LN, Kimmerling KA, Rueggeberg FA, Yiu CK, Mao J, Pashley DH, Tay FR. Effect of water-aging on the antimicrobial activities of an ORMOSIL-containing orthodontic acrylic resin. Acta Biomater 2013; 9:6964-73. [PMID: 23485857 DOI: 10.1016/j.actbio.2013.02.031] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 01/12/2013] [Accepted: 02/18/2013] [Indexed: 01/01/2023]
Abstract
Quaternary ammonium methacryloxy silicate (QAMS), an organically modified silicate (ORMOSIL) functionalized with polymerizable methacrylate groups and an antimicrobial agent with a long lipophilic alkyl chain quaternary ammonium group, was synthesized through a silane-based sol-gel route. By dissolving QAMS in methyl methacrylate monomer, this ORMOSIL molecule was incorporated into an auto-polymerizing, powder/liquid orthodontic acrylic resin system, yielding QAMS-containing poly(methyl methacrylate). The QAMS-containing acrylic resin showed a predominant contact-killing effect on Streptococcus mutans (ATCC 35668) and Actinomyces naeslundii (ATCC 12104) biofilms, while inhibiting adhesion of Candida albicans (ATCC 90028) on the acrylic surface. The antimicrobial activities of QAMS-containing acrylic resin were maintained after a 3month water-aging period. Bromophenol blue assay showed minimal leaching of quaternary ammonium species when an appropriate amount of QAMS (<4wt.%) was incorporated into the acrylic resin. The results suggest that QAMS is predominantly co-polymerized with the poly(methyl methacrylate) network, and only a minuscule amount of free QAMS molecules is present within the polymer network after water-aging. Acrylic resin with persistent antimicrobial activities represents a promising method for preventing bacteria- and fungus-induced stomatitis, an infectious disease commonly associated with the wearing of removable orthodontic appliances.
Collapse
|
12
|
Abstract
Antimicrobial surfaces for food and medical applications have historically involved antimicrobial coatings that elute biocides for effective kill in solution or at surfaces. However, recent efforts have focused on immobilized antimicrobial agents in order to avoid toxicity and the compatibility and reservoir limitations common to elutable agents. This review critically examines the assorted antimicrobial agents reported to have been immobilized, with an emphasis on the interpretation of antimicrobial testing as it pertains to discriminating between eluting and immobilized agents. Immobilization techniques and modes of antimicrobial action are also discussed.
Collapse
|
13
|
Mine Y, Nakatani T, Okamoto K, Makihira S, Iwata S, Nikawa H. Biomimetic Diamond-like Carbon coated Titanium Inhibits RANKL-dependent Osteoclast Differentiation in vitro. J PHOTOPOLYM SCI TEC 2012. [DOI: 10.2494/photopolymer.25.523] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
14
|
Arai T, Ueda T, Sugiyama T, Sakurai K. Inhibiting microbial adhesion to denture base acrylic resin by titanium dioxide coating. J Oral Rehabil 2011; 36:902-8. [PMID: 19941590 DOI: 10.1111/j.1365-2842.2009.02012.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Mechanical cleaning of dentures is effective in preventing infections such as aspiration pneumonia and denture stomatitis. For denture wearers with a physical handicap and the elderly, however, mechanical cleaning can present problems. The aim of this study was to investigate the effect of coating denture base acrylic resin with titanium dioxide (TiO(2)) in the inhibition of oral microbial adhesion. We prepared uniformly sized acrylic resin plates (10 mm x 10 mm x 0.5 mm), which were divided into two groups (a non-coated group and a TiO(2)-coated group). The plates were immersed in cultured Streptococcus sanguinis or Candida albicans and incubated for 24 h. After incubation, each plate was washed to remove loosely adherent microorganisms, and then incubated for a further 24 h. Adenosine triphosphate (ATP) content of the microorganisms was evaluated using a reagent containing benzalkonium, which extracts intra-cellular ATP. In addition, to determine biofilm formation, we also observed each plate by scanning electron microscopy (SEM). We found that the ATP content of both S. sanguinis and C. albicans was reduced by the TiO(2) coating (P = 0.000). Observation by SEM confirmed that the TiO(2) coating inhibited biofilm formation. The results indicate that a TiO(2) coating on a denture base acrylic resin inhibits adhesion of S. sanguinis and C. albicans.
Collapse
Affiliation(s)
- T Arai
- Department of Removable Prosthodontics and Gerodontology, Tokyo Dental College, Chiba 261-8502, Japan
| | | | | | | |
Collapse
|
15
|
Prevention of Candida albicans Biofilm Formation by Covalently Bound Dimethylaminoethylmethacrylate and Polyethylenimine. Mycopathologia 2010; 170:213-21. [DOI: 10.1007/s11046-010-9316-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Accepted: 04/22/2010] [Indexed: 10/19/2022]
|
16
|
Houari A, Di Martino P. Effect of chlorhexidine and benzalkonium chloride on bacterial biofilm formation. Lett Appl Microbiol 2007; 45:652-6. [DOI: 10.1111/j.1472-765x.2007.02249.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
17
|
Kébir N, Campistron I, Laguerre A, Pilard JF, Bunel C, Jouenne T. Use of telechelic cis-1,4-polyisoprene cationomers in the synthesis of antibacterial ionic polyurethanes and copolyurethanes bearing ammonium groups. Biomaterials 2007; 28:4200-8. [PMID: 17610950 DOI: 10.1016/j.biomaterials.2007.06.006] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2007] [Accepted: 06/05/2007] [Indexed: 11/26/2022]
Abstract
New crosslinked ionic polyurethanes and copolyurethanes were yielded by reaction of telechelic cis-1,4-oligoisoprenes, bearing a variable number of ammonium and hydroxy groups, with isocyanurate of isophorone diisocyanate (I-IPDI). Aiming for a comparative study, polyurethane elastomers based on non-ionic telechelic oligomers were also synthesized. Thermo-mechanical behavior and crosslinking density of these three families of materials were investigated by DMTA and swelling test, respectively. Surface properties were examined by static contact angle measurements and AFM imaging. The bactericidal activity of the polymers was investigated by enumerating living Pseudomonas aeruginosa on material surfaces and on water suspensions. The number of attached living bacteria was found to depend on the chemical structure of the material and on the contact time between the microorganisms and the surface. An exclusive bactericidal activity was obtained with the ionic copolyurethane family. Materials with weak crosslinking density were found to release bactericidal moieties. The abilities of the polymers to prevent bacterial growth were examined through zone of inhibition experiments against P. aeruginosa, which shown a bacteriostatical effect for each synthesized material. These experiments were not sufficiently sensitive to detect the leaching of bactericidal moieties from the materials with weak crosslinking density. When the zone of inhibition experiments was performed on more sensitive bacteria, namely Staphylococcus epidermidis, the leaching of bactericidal moieties as well as bacteriostatic effect was detected. This work demonstrates the potentiality for making functional biomaterials from natural rubber, a renewable resource.
Collapse
Affiliation(s)
- Nasreddine Kébir
- UMR 6011 CNRS (UCO2M), LCOM, Faculté des Sciences, Université du Maine, Avenue Olivier Messiaen, F-72085 Le Mans Cedex 9, France
| | | | | | | | | | | |
Collapse
|
18
|
Sultana R, Kon M, Hirakata LM, Fujihara E, Asaoka K, Ichikawa T. Surface Modification of Titanium with Hydrothermal Treatment at High Pressure. Dent Mater J 2006; 25:470-9. [PMID: 17076316 DOI: 10.4012/dmj.25.470] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Surface modification of titanium was investigated by means of hydrothermal treatment with a maximum pressure of 6.3 MPa (280 degrees C temperature) in CaO solution or water to improve bioactivity and biocompatibility. As a result, calcium titanate was formed on the titanium surface. Moreover, titanium oxide and titanium hydroxide layers on the surface increased as temperature and pressure increased. The surface-modified titanium was also immersed in a simulated body fluid (SBF) to estimate its bioactivity. Needle-like apatite precipitation was observed on all hydrothermal-treated titanium surfaces after immersion in SBF for four weeks. In particular, the apatite precipitation of titanium treated with 6.3 MPa in CaO solution was clearer and larger in amount than those of all other hydrothermal-treated specimens. Further, the amount of precipitate corresponded to the thickness of the surface-modified layer and the amount of calcium in the surface layer. The results suggested that surface modification of titanium with high-pressure hydrothermal treatment seemed to improve bioactivity and biocompatibility.
Collapse
Affiliation(s)
- Razia Sultana
- Department of Oral and Maxillofacial Prosthodontics and Oral Implantology, Institute of Health Biosciences, Tokushima University Graduate School, Japan
| | | | | | | | | | | |
Collapse
|