201
|
Schäfer T, Özalp VC. DNA-aptamer gating membranes. Chem Commun (Camb) 2015; 51:5471-4. [PMID: 25633657 PMCID: PMC4840836 DOI: 10.1039/c4cc09660f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 01/14/2015] [Indexed: 11/21/2022]
Abstract
This report describes a membrane barrier whose permeability is modulated through the recognition of a small-molecule target, adenosine triphosphate (ATP), by a DNA-aptamer. The gating function of the DNA-aptamer in the stimulus-responsive membrane was shown to be specific, concentration dependent, and reversible.
Collapse
Affiliation(s)
- Thomas Schäfer
- POLYMAT, University of the Basque Country, Av. Tolosa 72, 20018 Donostia-San Sebastián, Spain.
| | | |
Collapse
|
202
|
Leandro L, Malureanu R, Rozlosnik N, Lavrinenko A. Ultrathin, ultrasmooth gold layer on dielectrics without the use of additional metallic adhesion layers. ACS APPLIED MATERIALS & INTERFACES 2015; 7:5797-5802. [PMID: 25723253 DOI: 10.1021/am508681u] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
With advances in the plasmonics and metamaterials research field, it has become more and more important to fabricate thin and smooth Au metal films in a reliable way. Here, by thin films we mean that their average height is below 10 nm and their average roughness is below 5% of the total thickness. In this article, we investigated the use of amino- and mercaptosilanes to increase the adhesion of Au on Si wafers, thus obtaining a smooth and thin layer. This method does not include the use of other metals to improve the adhesion of gold, like Ti or Cr, since they would reduce the optical characteristics of the structure. Our results show that layers having 6 nm thickness and below 0.3 nm roughness can be reproducibly obtained using aminosilanes. Layers having a nominal thickness of 5 nm have a yield of 58%; thus, this thickness is the limit for the process that we investigated.
Collapse
Affiliation(s)
- Lorenzo Leandro
- †Department of Photonics Engineering and ‡Technical University of Denmark, Oersteds Plads, Building 345v, Room 178, DK-2800 Kongens Lyngby, Denmark
| | - Radu Malureanu
- †Department of Photonics Engineering and ‡Technical University of Denmark, Oersteds Plads, Building 345v, Room 178, DK-2800 Kongens Lyngby, Denmark
| | | | - Andrei Lavrinenko
- †Department of Photonics Engineering and ‡Technical University of Denmark, Oersteds Plads, Building 345v, Room 178, DK-2800 Kongens Lyngby, Denmark
| |
Collapse
|
203
|
Córdoba A, Satué M, Gómez-Florit M, Hierro-Oliva M, Petzold C, Lyngstadaas SP, González-Martín ML, Monjo M, Ramis JM. Flavonoid-modified surfaces: multifunctional bioactive biomaterials with osteopromotive, anti-inflammatory, and anti-fibrotic potential. Adv Healthc Mater 2015; 4:540-9. [PMID: 25335455 DOI: 10.1002/adhm.201400587] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Revised: 10/05/2014] [Indexed: 01/29/2023]
Abstract
Flavonoids are small polyphenolic molecules of natural origin with antioxidant, anti-inflammatory, and antibacterial properties. Here, a bioactive surface based on the covalent immobilization of flavonoids taxifolin and quercitrin on titanium substrates is presented, using (3-aminopropyl)triethoxysilane (APTES) as coupling agent. FTIR and XPS measurements confirm the grafting of the flavonoids to the surfaces. Using 2-aminoethyl diphenylborinate (DPBA, a flavonoid-specific dye), the modified surfaces are imaged by fluorescence microscopy. The bioactivity of the flavonoid-modified surfaces is evaluated in vitro with human umbilical cord derived mesenchymal stem cells (hUC-MSCs) and human gingival fibroblasts (HGFs) and compared to that of simple flavonoid coatings prepared by drop casting. Flavonoid-modified surfaces show anti-inflammatory and anti-fibrotic potential on HGF. In addition, Ti surfaces covalently functionalized with flavonoids promote the differentiation of hUC-MSCs to osteoblasts--enhancing the expression of osteogenic markers, increasing alkaline phosphatase activity and calcium deposition; while drop-casted surfaces do not. These findings could have a high impact in the development of advanced implantable medical devices like bone implants. Given the broad range of bioactivities of flavonoid compounds, these surfaces are ready to be explored for other biomedical applications, e.g., as stent surface or tumor-targeted functionalized nanoparticles for cardiovascular or cancer therapies.
Collapse
Affiliation(s)
- Alba Córdoba
- Group of Cell Therapy and Tissue Engineering; Research Institute on Health Sciences (IUNICS); University of the Balearic Islands; Ctra. Valldemossa km 7.5 07122 Palma de Mallorca Spain
| | - María Satué
- Group of Cell Therapy and Tissue Engineering; Research Institute on Health Sciences (IUNICS); University of the Balearic Islands; Ctra. Valldemossa km 7.5 07122 Palma de Mallorca Spain
| | - Manuel Gómez-Florit
- Group of Cell Therapy and Tissue Engineering; Research Institute on Health Sciences (IUNICS); University of the Balearic Islands; Ctra. Valldemossa km 7.5 07122 Palma de Mallorca Spain
| | - Margarita Hierro-Oliva
- Departamento de Física Aplicada; Facultad de Ciencias; Universidad de Extremadura; Badajoz Spain
- Biomedical Research Networking Center in Bioengineering; Biomaterials and Nanomedicine (CIBER-BBN); Spain
| | | | | | - María Luisa González-Martín
- Departamento de Física Aplicada; Facultad de Ciencias; Universidad de Extremadura; Badajoz Spain
- Biomedical Research Networking Center in Bioengineering; Biomaterials and Nanomedicine (CIBER-BBN); Spain
| | - Marta Monjo
- Group of Cell Therapy and Tissue Engineering; Research Institute on Health Sciences (IUNICS); University of the Balearic Islands; Ctra. Valldemossa km 7.5 07122 Palma de Mallorca Spain
| | - Joana M. Ramis
- Group of Cell Therapy and Tissue Engineering; Research Institute on Health Sciences (IUNICS); University of the Balearic Islands; Ctra. Valldemossa km 7.5 07122 Palma de Mallorca Spain
| |
Collapse
|
204
|
Vutti S, Buch-Månson N, Schoffelen S, Bovet N, Martinez KL, Meldal M. Covalent and Stable CuAAC Modification of Silicon Surfaces for Control of Cell Adhesion. Chembiochem 2015; 16:782-91. [DOI: 10.1002/cbic.201402629] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Indexed: 12/16/2022]
|
205
|
Hreczycho G, Frydrych-Tomczak E, Sterzynska K, Budna J, Malinska A, Maciejewski H, Zabel M. Novel organosilicon dendrons as effective linkers for biomolecules binding on a glass surface. Appl Organomet Chem 2015. [DOI: 10.1002/aoc.3272] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
| | - Emilia Frydrych-Tomczak
- Wroclaw Research Center EIT+; BioMed; 54-066 Wroclaw Poland
- Poznan Science and Technology Park; Adam Mickiewicz University Foundation; 61-612 Poznan Poland
| | - Karolina Sterzynska
- Wroclaw Research Center EIT+; BioMed; 54-066 Wroclaw Poland
- Department of Histology and Embryology; Poznan University of Medical Sciences; 60-781 Poznan Poland
| | - Joanna Budna
- Wroclaw Research Center EIT+; BioMed; 54-066 Wroclaw Poland
| | - Agnieszka Malinska
- Wroclaw Research Center EIT+; BioMed; 54-066 Wroclaw Poland
- Department of Histology and Embryology; Poznan University of Medical Sciences; 60-781 Poznan Poland
| | - Hieronim Maciejewski
- Faculty of Chemistry; Adam Mickiewicz University; 61-614 Poznan Poland
- Poznan Science and Technology Park; Adam Mickiewicz University Foundation; 61-612 Poznan Poland
| | - Maciej Zabel
- Wroclaw Research Center EIT+; BioMed; 54-066 Wroclaw Poland
- Department of Histology and Embryology; Poznan University of Medical Sciences; 60-781 Poznan Poland
| |
Collapse
|
206
|
Singh G, Arora A, Mangat SS, Singh J, Rani S, Kaur N. Synthetic investigations and photo-physical properties of 1,2,3-triazole encapped chalconyl substituted organotriethoxysilanes. J Organomet Chem 2015. [DOI: 10.1016/j.jorganchem.2014.11.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
|
207
|
Hu F, Chen K, Xu H, Gu H. Functional short-chain zwitterion coated silica nanoparticles with antifouling property in protein solutions. Colloids Surf B Biointerfaces 2015; 126:251-6. [DOI: 10.1016/j.colsurfb.2014.12.036] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Revised: 12/04/2014] [Accepted: 12/18/2014] [Indexed: 12/28/2022]
|
208
|
Hu X, Dinu CZ. Analysis of affinities between specific biological ligands using atomic force microscopy. Analyst 2015; 140:8118-26. [PMID: 26525901 DOI: 10.1039/c5an01748c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We used atomic force microscopy to rank the energetics of biomolecular recognition events of protein–ligand complexes.
Collapse
Affiliation(s)
- Xiao Hu
- West Virginia University
- Department of Chemical Engineering
- Morgantown
- USA
| | | |
Collapse
|
209
|
Sun P, Liu G, Lv D, Dong X, Wu J, Wang D. Effective activation of halloysite nanotubes by piranha solution for amine modification via silane coupling chemistry. RSC Adv 2015. [DOI: 10.1039/c5ra04444h] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Piranha solution is shown to be an effective agent in activating the surface of HNTs for silanization modification.
Collapse
Affiliation(s)
- Pan Sun
- Beijing National Laboratory for Molecular Sciences
- CAS Key Laboratory of Engineering Plastics
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
| | - Guoming Liu
- Beijing National Laboratory for Molecular Sciences
- CAS Key Laboratory of Engineering Plastics
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
| | - Dong Lv
- Department of Mechanical and Aerospace Engineering
- The Hong Kong University of Science and Technology
- China
| | - Xia Dong
- Beijing National Laboratory for Molecular Sciences
- CAS Key Laboratory of Engineering Plastics
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
| | - Jingshen Wu
- Department of Mechanical and Aerospace Engineering
- The Hong Kong University of Science and Technology
- China
| | - Dujin Wang
- Beijing National Laboratory for Molecular Sciences
- CAS Key Laboratory of Engineering Plastics
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
| |
Collapse
|
210
|
Käpylä E, Sorkio A, Teymouri S, Lahtonen K, Vuori L, Valden M, Skottman H, Kellomäki M, Juuti-Uusitalo K. Ormocomp-modified glass increases collagen binding and promotes the adherence and maturation of human embryonic stem cell-derived retinal pigment epithelial cells. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:14555-65. [PMID: 25375206 DOI: 10.1021/la5023642] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
In in vitro live-cell imaging, it would be beneficial to grow and assess human embryonic stem cell-derived retinal pigment epithelial (hESC-RPE) cells on thin, transparent, rigid surfaces such as cover glasses. In this study, we assessed how the silanization of glass with 3-aminopropyltriethoxysilane (APTES), 3-(trimethoxysilyl)propyl methacrylate (MAPTMS), or polymer-ceramic material Ormocomp affects the surface properties, protein binding, and maturation of hESC-RPE cells. The surface properties were studied by contact angle measurements, X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and a protein binding assay. The cell adherence and proliferation were evaluated by culturing hESCRPE cells on collagen IV-coated untreated or silanized surfaces for 42 days. The Ormocomp treatment significantly increased the hydrophobicity and roughness of glass surfaces compared to the APTES and MAPTMS treatments. The XPS results indicated that the Ormocomp treatment changes the chemical composition of the glass surface by increasing the carbon content and the number of C-O/═O bonds. The protein-binding test confirmed that the Ormocomp-treated surfaces bound more collagen IV than did APTES- or MAPTMS-treated surfaces. All of the silane treatments increased the number of cells: after 42 days of culture, Ormocomp had 0.38, APTES had 0.16, MAPTMS had 0.19, and untreated glass had only 0.062, all presented as million cells cm(-2). There were no differences in cell numbers compared to smoother to rougher Ormocomp surfaces, suggesting that the surface chemistry and, more specifically, the collagen binding in combination with Ormocomp are beneficial to hESC-RPE cell culture. This study clearly demonstrates that Ormocomp treatment combined with collagen coating significantly increases hESC-RPE cell attachment compared to commonly used silanizing agents APTES and MAPTMS. Ormocomp silanization could thus enable the use of microscopic live cell imaging methods for hESC-RPE cells.
Collapse
|
211
|
Yu M, Chen S, Zhang B, Qiu D, Cui S. Why a lotus-like superhydrophobic surface is self-cleaning? An explanation from surface force measurements and analysis. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:13615-21. [PMID: 25335800 DOI: 10.1021/la5041272] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The unique self-cleaning feature of the lotus-like superhydrophobic (SH) surface attracted worldwide interest in recent years. However, the mechanism of the self-cleaning phenomena remains unclear. Here, we attempt to provide a comprehensive understanding of why self-cleaning of the particles with a broad range of size can be realized on the lotus-like SH surfaces. After measurements and analysis of the force involved at the interface, we conclude that there are four main preconditions for self-cleaning: (1) contact angle (CA) > 90°, (2) low enough sliding angle, (3) low enough adhesion force, and (4) proper particle size. However, as far as the lotus-like SH surface and typical dust are concerned, all the preconditions will be satisfied automatically. We also observe that the particles with a broad range of size (from submicron level to the millimeter level) and density (virtually no limit) can be driven by a water droplet on the lotus-like SH surface. This interesting finding may be helpful for the design of novel engineering system at the micron-millimeter scale in the future.
Collapse
Affiliation(s)
- Miao Yu
- Key Laboratory of Advanced Technologies of Materials (Ministry of Education), Southwest Jiaotong University , Chengdu 610031, China
| | | | | | | | | |
Collapse
|
212
|
Siriviriyanun A, Imae T. Solvo-affinity property of glass surfaces modified by self-assembled monolayers of organic and/or inorganic chemicals. J Taiwan Inst Chem Eng 2014. [DOI: 10.1016/j.jtice.2014.06.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
213
|
Vashist SK, Lam E, Hrapovic S, Male KB, Luong JHT. Immobilization of Antibodies and Enzymes on 3-Aminopropyltriethoxysilane-Functionalized Bioanalytical Platforms for Biosensors and Diagnostics. Chem Rev 2014; 114:11083-130. [DOI: 10.1021/cr5000943] [Citation(s) in RCA: 212] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Sandeep Kumar Vashist
- HSG-IMIT - Institut für Mikro- und Informationstechnik, Georges-Koehler-Allee 103, 79110 Freiburg, Germany
- Laboratory for MEMS Applications, Department of Microsystems Engineering - IMTEK, University of Freiburg, Georges-Koehler-Allee 103, 79110 Freiburg, Germany
| | - Edmond Lam
- National Research Council Canada, Montreal, Quebec H4P 2R2, Canada
| | | | - Keith B. Male
- National Research Council Canada, Montreal, Quebec H4P 2R2, Canada
| | - John H. T. Luong
- Innovative Chromatography Group, Irish Separation Science Cluster (ISSC), Department of Chemistry and Analytical, Biological Chemistry Research Facility (ABCRF), University College Cork, Cork, Ireland
| |
Collapse
|
214
|
Kamiya Y, Yamazaki K, Ogino T. Protein adsorption to graphene surfaces controlled by chemical modification of the substrate surfaces. J Colloid Interface Sci 2014; 431:77-81. [DOI: 10.1016/j.jcis.2014.06.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 05/08/2014] [Accepted: 06/11/2014] [Indexed: 10/25/2022]
|
215
|
Wang Y, Liu J, Wang P, Werth CJ, Strathmann TJ. Palladium Nanoparticles Encapsulated in Core–Shell Silica: A Structured Hydrogenation Catalyst with Enhanced Activity for Reduction of Oxyanion Water Pollutants. ACS Catal 2014. [DOI: 10.1021/cs500971r] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Yin Wang
- Department
of Civil and Environmental Engineering, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Jinyong Liu
- Department
of Civil and Environmental Engineering, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Peng Wang
- Water
Desalination and Reuse Center, Biological and Environmental Sciences
and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Charles J. Werth
- Department
of Civil and Environmental Engineering, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Timothy J. Strathmann
- Department
of Civil and Environmental Engineering, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| |
Collapse
|
216
|
Ozgur E, Toren P, Bayindir M. Phosphonate based organosilane modification of a simultaneously protein resistant and bioconjugable silica surface. J Mater Chem B 2014; 2:7118-7122. [DOI: 10.1039/c4tb01283f] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
217
|
Deetz JD, Faller R. Parallel Optimization of a Reactive Force Field for Polycondensation of Alkoxysilanes. J Phys Chem B 2014; 118:10966-78. [DOI: 10.1021/jp504138r] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Joshua D. Deetz
- Department of Chemical Engineering & Materials Science, University of California, Davis 95616, California, United States
| | - Roland Faller
- Department of Chemical Engineering & Materials Science, University of California, Davis 95616, California, United States
| |
Collapse
|
218
|
Zhou L, Chen M, Guan Y, Zhang Y. Multiple responsive hydrogel films based on dynamic Schiff base linkages. Polym Chem 2014. [DOI: 10.1039/c4py00868e] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
219
|
Hernàndez-Navarro S, Tierno P, Farrera JA, Ignés-Mullol J, Sagués F. Reconfigurable Swarms of Nematic Colloids Controlled by Photoactivated Surface Patterns. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201406136] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
220
|
Hernàndez-Navarro S, Tierno P, Farrera JA, Ignés-Mullol J, Sagués F. Reconfigurable swarms of nematic colloids controlled by photoactivated surface patterns. Angew Chem Int Ed Engl 2014; 53:10696-700. [PMID: 25139525 DOI: 10.1002/anie.201406136] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Indexed: 11/08/2022]
Abstract
Different phoretic driving mechanisms have been proposed for the transport of solid or liquid microscopic inclusions in integrated chemical processes. It is now shown that a substrate that was chemically modified with photosensitive self-assembled monolayers enables the direct control of the assembly and transport of large ensembles of micrometer-sized particles and drops that were dispersed in a thin layer of anisotropic fluid. This strategy separates particle driving, which was realized by AC electrophoresis, and steering, which was achieved by elastic modulation of the nematic host fluid. Inclusions respond individually or in collective modes following arbitrary reconfigurable paths that were imprinted by irradiation with UV or blue light. Relying solely on generic material properties, the proposed procedure is versatile enough for the development of applications that involve either inanimate or living materials.
Collapse
Affiliation(s)
- Sergi Hernàndez-Navarro
- Department of Physical Chemistry, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Catalonia (Spain); Institut de Nanociència i Nanotecnologia, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Catalonia (Spain)
| | | | | | | | | |
Collapse
|
221
|
Teixeira S, Conlan RS, Guy O, Sales MGF. Novel single-wall carbon nanotube screen-printed electrode as an immunosensor for human chorionic gonadotropin. Electrochim Acta 2014. [DOI: 10.1016/j.electacta.2014.05.105] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|
222
|
Tokel O, Inci F, Demirci U. Advances in plasmonic technologies for point of care applications. Chem Rev 2014; 114:5728-52. [PMID: 24745365 PMCID: PMC4086846 DOI: 10.1021/cr4000623] [Citation(s) in RCA: 215] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Indexed: 12/12/2022]
Affiliation(s)
- Onur Tokel
- Demirci
Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical
School, Cambridge, Massachusetts 02139, United States
| | - Fatih Inci
- Demirci
Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical
School, Cambridge, Massachusetts 02139, United States
- Demirci
Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Stanford University School of Medicine, Canary Center at Stanford
for Cancer Early Detection, Palo
Alto, California 94304, United States
| | - Utkan Demirci
- Demirci
Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical
School, Cambridge, Massachusetts 02139, United States
- Division of Infectious Diseases, Brigham
and Women’s Hospital, Harvard Medical
School, Boston, Massachusetts 02115, United States
- Harvard-MIT
Health Sciences and Technology, Cambridge, Massachusetts 02139, United States
- Demirci
Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Stanford University School of Medicine, Canary Center at Stanford
for Cancer Early Detection, Palo
Alto, California 94304, United States
| |
Collapse
|
223
|
Ammar M, Smadja C, Ly GTP, Tandjigora D, Vigneron J, Etcheberry A, Taverna M, Dufour-Gergam E. Chemical engineering of self-assembled Alzheimer's peptide on a silanized silicon surface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:5863-5872. [PMID: 24654702 DOI: 10.1021/la500695y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The aim of this work is to develop a sensitive and specific immune-sensing platform dedicated to the detection of potential biomarkers of Alzheimer's disease (AD) in biological fluids. Accordingly, a controlled and adaptive surface functionalization of a silicon wafer with 7-octenyltrichlorosilane has been performed. The surface has extensively been characterized by atomic force microscopy (AFM; morphology) and X-ray photoelectron spectroscopy (XPS; chemical composition) and contact angle measurements. The wettability of the grafted chemical groups demonstrated the gradual trend from hydrophilic to hydrophobic surface during functionalization. XPS evidenced the presence of silanes on the surface after silanization, and even carboxylic groups as products from the oxidation step of the functionalization process. The characterization results permitted us to define an optimal protocol to reach a high-quality grafting yield. The issue of the quality of controlled chemical preparation on bioreceiving surfaces was also investigated by the recognition of one AD biomarker, the amyloid peptide Aβ 1-42. We have therefore evaluated the biological activity of the grafted anti Aβ antibodies onto this silanized surface by fluorescent microscopy. In conclusion, we have shown, both qualitatively and quantitatively, the uniformity of the optimized functionalization on slightly oxidized silicon surfaces, providing a reliable and chemically stable procedure to determine specific biomarkers of Alzheimer disease. This work opens the route to the integration of controlled immune-sensing applications on lab-on-chip systems.
Collapse
Affiliation(s)
- Mehdi Ammar
- Université Paris Sud , Institut d'Electronique Fondamentale, UMR 8622, Orsay F-91405, France
| | | | | | | | | | | | | | | |
Collapse
|
224
|
Pujari SP, Scheres L, Marcelis ATM, Zuilhof H. Covalent Surface Modification of Oxide Surfaces. Angew Chem Int Ed Engl 2014; 53:6322-56. [DOI: 10.1002/anie.201306709] [Citation(s) in RCA: 583] [Impact Index Per Article: 58.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Indexed: 12/26/2022]
Affiliation(s)
- Sidharam P. Pujari
- Laboratory of Organic Chemistry, Wageningen University, P.O. Box 26, 6703 HB Wageningen (The Netherlands)
| | - Luc Scheres
- Surfix B.V. Dreijenplein 8, 6703 HB Wageningen (The Netherlands)
| | - Antonius T. M. Marcelis
- Laboratory of Organic Chemistry, Wageningen University, P.O. Box 26, 6703 HB Wageningen (The Netherlands)
| | - Han Zuilhof
- Laboratory of Organic Chemistry, Wageningen University, P.O. Box 26, 6703 HB Wageningen (The Netherlands)
- Department of Chemical and Materials Engineering, King Abdulaziz University, Jeddah (Saudi Arabia)
| |
Collapse
|
225
|
Pujari SP, Scheres L, Marcelis ATM, Zuilhof H. Kovalente Oberflächenmodifikationen von Oxiden. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201306709] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Sidharam P. Pujari
- Laboratory of Organic Chemistry, Wageningen University, P.O. Box 26, 6703 HB Wageningen (Niederlande)
| | | | - Antonius T. M. Marcelis
- Laboratory of Organic Chemistry, Wageningen University, P.O. Box 26, 6703 HB Wageningen (Niederlande)
| | - Han Zuilhof
- Laboratory of Organic Chemistry, Wageningen University, P.O. Box 26, 6703 HB Wageningen (Niederlande)
- Department of Chemical and Materials Engineering, King Abdulaziz University, Jeddah (Saudi‐Arabien)
| |
Collapse
|
226
|
Donesz-Sikorska A, Grzesiak J, Śmieszeka A, Krzak J, Marycz K. The influence of sol–gel-derived silica coatings functionalized with betamethasone on adipose-derived stem cells (ASCs). J Biomater Appl 2014; 29:465-76. [DOI: 10.1177/0885328214534003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Silica-based sol–gel coatings have gained attention in bone therapies and orthopedic applications, due to the biocompatibility and bioactivity, including a high potential for the controlled release both in vitro and in vivo. Bioactive materials are created to facilitate the biocompatibility of orthopedic implants. One of the promising alternatives is biomaterials with immobilized drugs. In this study we demonstrated for the first time novel sol–gel-derived silica coatings with active amino groups (SiO2(NH2)) functionalized with a steroid drug—betamethasone, applied to a substrate 316 L using dip coating technique. The presence of betamethasone in functionalized coatings was directly confirmed by Raman spectroscopy and energy-dispersive X-ray spectroscopic analysis. The wettability was evaluated by the sessile drop method, while the surface free energy was estimated based on the contact angles measured. Our results showed a shift in surface properties from hydrophobic to hydrophilic after application of the coatings. We have investigated the morphology, proliferation factor, and the population doubling time of adipose-derived stem cells for biological purposes. Moreover, the analysis of the distribution and localization of cellular microvesicles was performed to evaluate the influence of functionalized surfaces on cellular cytophysiological activity. Increased proliferation and activation of cells, determined by the observations of microvesicles shedding processes, provided evidence of the availability of the drug. Therefore, we conclude that the sol–gel synthesis proposed here allows to improve the metal substrates and can be successfully used for immobilization of betamethasone. This in turn enables the direct delivery of the drug with implanted material into the wound site, and to stimulate the activity of cells to enhance tissue regeneration.
Collapse
Affiliation(s)
- Anna Donesz-Sikorska
- Department of Mechanics, Materials Science and Engineering, Wroclaw University of Technology, Wroclaw, Poland
| | - Jakub Grzesiak
- Electron Microscopy Laboratory, University of Environmental and Life Sciences Wroclaw, Wroclaw, Poland
- EIT+ Wroclaw Research Centre EIT+, Wroclaw, Poland
| | - Agnieszk Śmieszeka
- Electron Microscopy Laboratory, University of Environmental and Life Sciences Wroclaw, Wroclaw, Poland
- EIT+ Wroclaw Research Centre EIT+, Wroclaw, Poland
| | - Justyna Krzak
- Department of Mechanics, Materials Science and Engineering, Wroclaw University of Technology, Wroclaw, Poland
| | - Krzysztof Marycz
- Electron Microscopy Laboratory, University of Environmental and Life Sciences Wroclaw, Wroclaw, Poland
- EIT+ Wroclaw Research Centre EIT+, Wroclaw, Poland
| |
Collapse
|
227
|
Shirai K, Mawatari K, Kitamori T. Extended nanofluidic immunochemical reaction with femtoliter sample volumes. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2014; 10:1514-1522. [PMID: 24339226 DOI: 10.1002/smll.201302709] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2013] [Revised: 09/28/2013] [Indexed: 06/03/2023]
Abstract
The growing need to optimize immunoassay performance driven by interest in analyzing individual cells has resulted in a decrease in the amount of sample required. Miniaturized immunoassays that use ultra-small femtoliter to attoliter sample volumes, a range known as the extended nanospace, can satisfy this analytical need; however, capturing every targeted molecule without loss in extended nanochannels for subsequent detection remains challenging. This is the first report of a successful extended nanofluidics-based quantitative immunochemical reaction capable of high capture efficiency using a femtoliter-scale sample volume. A novel patterning method using a photolithographic technique with vacuum ultraviolet light and low-temperature (100 °C) bonding enables patterning of functional groups for antibody immobilization before bonding, resulting in an immunochemical reaction space of only 86 fL. Reaction rate analyses indicate a decrease in the required sample volume to 810 fL and improvement in the limit of detection to 3 zmol, 5-6 orders of magnitude better than possible with the microfluidic immunoassay format. Highly efficient (near 100%) immunochemical reactions on a seconds time scale are possible due to the nm-scale diffusion length, which should be advantageous for the analysis of ultra-low-volume samples.
Collapse
Affiliation(s)
- Kentaro Shirai
- Department of Bioengineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo, 113-8656, Japan
| | | | | |
Collapse
|
228
|
Aissaoui N, Bergaoui L, Boujday S, Lambert JF, Méthivier C, Landoulsi J. Enzyme immobilization on silane-modified surface through short linkers: fate of interfacial phases and impact on catalytic activity. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:4066-4077. [PMID: 24635492 DOI: 10.1021/la404935q] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We investigated the mechanism of enzyme immobilization on silanized surfaces through coupling agents (cross-linkers) in order to understand the role of these molecules on interfacial processes and their effect on catalytic activity. To this end, we used a model multimeric enzyme (G6PDH) and several cross-linking molecules with different chemical properties, including the nature of the end-group (-NCO, -NCS, -CHO), the connecting chain (aliphatic vs aromatic), and geometrical constraints (meta vs para-disubstituted aromatics). There did not seem to be radical differences in the mechanism of enzyme adsorption according to the linker used as judged from QCM-D, except that in the case of DIC (1,4-phenylene diisocyanate) the adsorption occurred more rapidly. In contrast, the nature of the cross-linker exerted a strong influence on the amount of enzyme immobilized as estimated from XPS, and more unexpectedly on the stability of the underlying silane layer. DIC, PDC (1,4-phenylene diisothiocyanate), or GA (glutaraldehyde) allowed successful enzyme immobilization. When the geometry of the linker was changed from 1,4-phenylene diisothiocyanate to 1,3-phenylene diisothiocyanate (MDC), the silane layer was subjected to degradation, upon enzyme adsorption, and the amount of immobilized molecules was significantly lowered. TE (terephtalaldehyde) and direct enzyme deposition without cross-linker were similar to MDC. The organization of immobilized enzymes also depended on the immobilization procedure, as different degrees of aggregation were observed by AFM. A correlation between the size of the aggregates and the catalytic properties of the enzyme was established, suggesting that aggregation may enhance the thermostability of the multimeric enzyme, probably through a compaction of the 3D structure.
Collapse
Affiliation(s)
- Nesrine Aissaoui
- Sorbonne Universités, UPMC Univ Paris 06 , F-75005, Paris, France
| | | | | | | | | | | |
Collapse
|
229
|
Dworak A, Utrata-Wesołek A, Oleszko N, Wałach W, Trzebicka B, Anioł J, Sieroń AL, Klama-Baryła A, Kawecki M. Poly(2-substituted-2-oxazoline) surfaces for dermal fibroblasts adhesion and detachment. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2014; 25:1149-1163. [PMID: 24390278 DOI: 10.1007/s10856-013-5135-7] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Accepted: 12/23/2013] [Indexed: 06/03/2023]
Abstract
The thermoresponsive surfaces of brush structure (linear polymer chains tethered on the surface) based on poly(2-isopropyl-2-oxazoline)s and copolymers of 2-ethyl-2-oxazoline and 2-nonyl-2-oxazoline were obtained using the grafting-to method. The living oxazoline (co)polymers have been synthesized by cationic ring-opening polymerization and subsequently terminated by the reactive amine groups present on the surface. The changes in the surface morphology, philicity and thickness occurring during surface modification were monitored via atomic force microscopy, contact angle and ellipsometry. The thickness of the (co)poly(2-substituted-2-oxazoline) layers ranged from 4 to 11 nm depending on the molar mass of immobilized polymer and reversibly varied with the temperature changes. This confirmed thermoresponsive properties of obtained surfaces. The obtained polymer surfaces were used as a support for dermal fibroblast culture and detachment. The fibroblasts' adhesion and proliferation on the polymer surfaces were observed when the culture temperature was above the cloud point temperature of the immobilized polymer. Lowering the temperature resulted in the detachment of the dermal fibroblast sheets from the polymer layers, which makes these surfaces suitable for the treatment of wounds and in skin tissue engineering.
Collapse
Affiliation(s)
- Andrzej Dworak
- Center of Polymer and Carbon Materials, Polish Academy of Sciences, M. Curie-Sklodowskiej 34, 41-819, Zabrze, Poland,
| | | | | | | | | | | | | | | | | |
Collapse
|
230
|
Kumar N, Froner E, Guider R, Scarpa M, Bettotti P. Investigation of non-specific signals in nanoporous flow-through and flow-over based sensors. Analyst 2014; 139:1345-9. [PMID: 24416760 DOI: 10.1039/c3an01996a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Porous materials are ideal hosts to fabricate high sensitivity devices. Their large specific area and the possibility to modify the type and the strength of the matrix-analyte interactions allow the realization of sensors with finely tailored characteristics. In this article, we investigate how mass transport across the nanoporous structure influences the response due to the non-specific signal by comparing flow-through versus flow-over geometries. We observed a systematic overestimation of the sensitivity for porous substrate devices made of closed-ended pores compared with open-ended pore ones. Our analysis shows that such an effect is due to (unbound) analytes or contaminants that remain trapped within the pores and are not removed by rinsing of the sample. This result was verified by measuring similar samples in both flow through and flow over configurations, as well as their residual response after blockage of all their active sites. We also notice that sensors based on free-standing membranes show similar results independent of the fact that mass transport is induced by either an external pressure source or simply by Brownian motions.
Collapse
Affiliation(s)
- Neeraj Kumar
- Nanoscience Laboratory, Department of Physics, University of Trento, 38123 Povo, Italy.
| | | | | | | | | |
Collapse
|
231
|
Dubacheva GV, Devynck M, Raffy G, Hirsch L, Del Guerzo A, Bassani DM. Probing lateral charge transport in single molecule layers: how charge is transported over long distances in fullerene self-assembled monolayers. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2014; 10:454-461. [PMID: 24014211 DOI: 10.1002/smll.201300502] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Revised: 07/22/2013] [Indexed: 06/02/2023]
Affiliation(s)
- Galina V Dubacheva
- Univ. Bordeaux 1, Institut des Sciences Moléculaires, CNRS UMR 5255, Talence, France
| | | | | | | | | | | |
Collapse
|
232
|
Taglietti A, Arciola CR, D'Agostino A, Dacarro G, Montanaro L, Campoccia D, Cucca L, Vercellino M, Poggi A, Pallavicini P, Visai L. Antibiofilm activity of a monolayer of silver nanoparticles anchored to an amino-silanized glass surface. Biomaterials 2014; 35:1779-88. [DOI: 10.1016/j.biomaterials.2013.11.047] [Citation(s) in RCA: 141] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Accepted: 11/17/2013] [Indexed: 12/13/2022]
|
233
|
Nicholas MP, Rao L, Gennerich A. Covalent immobilization of microtubules on glass surfaces for molecular motor force measurements and other single-molecule assays. Methods Mol Biol 2014; 1136:137-69. [PMID: 24633798 PMCID: PMC4258907 DOI: 10.1007/978-1-4939-0329-0_9] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Rigid attachment of microtubules (MTs) to glass cover slip surfaces is a prerequisite for a variety of microscopy experiments in which MTs are used as substrates for MT-associated proteins, such as the molecular motors kinesin and cytoplasmic dynein. We present an MT-surface coupling protocol in which aminosilanized glass is formylated using the cross-linker glutaraldehyde, fluorescence-labeled MTs are covalently attached, and the surface is passivated with highly pure beta-casein. The technique presented here yields rigid MT immobilization while simultaneously blocking the remaining glass surface against nonspecific binding by polystyrene optical trapping microspheres. This surface chemistry is straightforward and relatively cheap and uses a minimum of specialized equipment or hazardous reagents. These methods provide a foundation for a variety of optical tweezers experiments with MT-associated molecular motors and may also be useful in other assays requiring surface-immobilized proteins.
Collapse
Affiliation(s)
- Matthew P Nicholas
- Department of Anatomy and Structural Biology, Gruss Lipper Biophotonics Center, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY, 10461, USA
| | | | | |
Collapse
|
234
|
Kang C, Crockett RM, Spencer ND. Molecular-Weight Determination of Polymer Brushes Generated by SI-ATRP on Flat Surfaces. Macromolecules 2013. [DOI: 10.1021/ma401951w] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Chengjun Kang
- Laboratory
for Surface Science and Technology, Department of Materials, ETH Zurich, Wolfgang-Pauli-Strasse 10, CH 8093 Zurich, Switzerland
| | - Rowena M. Crockett
- Swiss Federal
Laboratories for Materials Science and Technology, Empa, Ueberlandstrasse 129, CH 8600 Duebendorf, Switzerland
| | - Nicholas D. Spencer
- Laboratory
for Surface Science and Technology, Department of Materials, ETH Zurich, Wolfgang-Pauli-Strasse 10, CH 8093 Zurich, Switzerland
| |
Collapse
|
235
|
Cao A, Sudhölter EJR, de Smet LCPM. Silicon nanowire-based devices for gas-phase sensing. SENSORS 2013; 14:245-71. [PMID: 24368699 PMCID: PMC3926556 DOI: 10.3390/s140100245] [Citation(s) in RCA: 106] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 11/12/2013] [Accepted: 11/18/2013] [Indexed: 01/29/2023]
Abstract
Since their introduction in 2001, SiNW-based sensor devices have attracted considerable interest as a general platform for ultra-sensitive, electrical detection of biological and chemical species. Most studies focus on detecting, sensing and monitoring analytes in aqueous solution, but the number of studies on sensing gases and vapors using SiNW-based devices is increasing. This review gives an overview of selected research papers related to the application of electrical SiNW-based devices in the gas phase that have been reported over the past 10 years. Special attention is given to surface modification strategies and the sensing principles involved. In addition, future steps and technological challenges in this field are addressed.
Collapse
Affiliation(s)
| | | | - Louis C P M de Smet
- Department of Chemical Engineering, Delft University of Technology, Julianalaan 136, Delft 2628 BL, The Netherlands.
| |
Collapse
|
236
|
Liu Y, Li Y, Li XM, He T. Kinetics of (3-aminopropyl)triethoxylsilane (APTES) silanization of superparamagnetic iron oxide nanoparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:15275-82. [PMID: 24256348 DOI: 10.1021/la403269u] [Citation(s) in RCA: 93] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Silanization of magnetic ironoxide nanoparticles with (3-aminopropyl)triethoxylsilane (APTES) is reported. The kinetics of silanization toward saturation was investigated using different solvents including water, water/ethanol (1/1), and toluene/methanol (1/1) at different reaction temperature with different APTES loading. The nanoparticles were characterized by Fourier transform infrared spectroscopy, vibrating sample magnetometry, transmission electron microscopy, and thermal gravimetric analysis (TGA). Grafting density data based on TGA were used for the kinetic modeling. It is shown that initial silanization takes place very fast but the progress toward saturation is very slow, and the mechanism may involve adsorption, chemical sorption, and chemical diffusion processes. The highest equilibrium grafting density of 301 mg/g was yielded when using toluene/methanol mixture as the solvent at a reaction temperature of 70 °C.
Collapse
Affiliation(s)
- Yue Liu
- Shanghai Advanced Research Institute , Chinese Academy of Sciences, Shanghai, China 201210
| | | | | | | |
Collapse
|
237
|
Seo JY, Lee K, Lee SY, Jeon SG, Na JG, Oh YK, Park SB. Effect of barium ferrite particle size on detachment efficiency in magnetophoretic harvesting of oleaginous Chlorella sp. BIORESOURCE TECHNOLOGY 2013; 152:562-566. [PMID: 24333146 DOI: 10.1016/j.biortech.2013.11.064] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 11/18/2013] [Accepted: 11/24/2013] [Indexed: 06/03/2023]
Abstract
Microalgal biofuel is garnering many positive and promising reviews as a fuel for the next generation while research effort continues to improve the efficiency of its harvesting for commercial success. In this report, magnetophoretic harvesting of microalgae is conducted through a three-step process, which includes functionalization of magnetic particles by (3-aminopropyl)triethoxysilane (APTES), magnetic separation, and detachment of magnetic particles by increasing pH to higher than the isoelectric point. Detachment process is specifically focused and found that the use of larger magnetic particles is more efficient for detachment of magnetic particles from algae-particle conglomerates. The detaching efficiency improves from 12.5% to 85% when the particle size is increased from 108 nm to 1.17 μm. Smaller magnetic particles provide larger contact area to microalgae and form strong electrostatic binding to negatively-charged microalgae when pH is lower than the isoelectric point.
Collapse
Affiliation(s)
- Jung Yoon Seo
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | - Kyubock Lee
- Clean Fuel Department, Korea Institute of Energy Research, 152 Gajeong-ro, Yuseong-gu, Daejeon 305-343, Republic of Korea
| | - So Yeun Lee
- Clean Fuel Department, Korea Institute of Energy Research, 152 Gajeong-ro, Yuseong-gu, Daejeon 305-343, Republic of Korea
| | - Sang Goo Jeon
- Clean Fuel Department, Korea Institute of Energy Research, 152 Gajeong-ro, Yuseong-gu, Daejeon 305-343, Republic of Korea
| | - Jeong-Geol Na
- Clean Fuel Department, Korea Institute of Energy Research, 152 Gajeong-ro, Yuseong-gu, Daejeon 305-343, Republic of Korea
| | - You-Kwan Oh
- Clean Fuel Department, Korea Institute of Energy Research, 152 Gajeong-ro, Yuseong-gu, Daejeon 305-343, Republic of Korea.
| | - Seung Bin Park
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
| |
Collapse
|
238
|
Yadav AR, Sriram R, Carter JA, Miller BL. Comparative study of solution-phase and vapor-phase deposition of aminosilanes on silicon dioxide surfaces. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2013; 35:283-90. [PMID: 24411379 DOI: 10.1016/j.msec.2013.11.017] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Revised: 10/03/2013] [Accepted: 11/08/2013] [Indexed: 02/06/2023]
Abstract
The uniformity of aminosilane layers typically used for the modification of hydroxyl bearing surfaces such as silicon dioxide is critical for a wide variety of applications, including biosensors. However, in spite of many studies that have been undertaken on surface silanization, there remains a paucity of easy-to-implement deposition methods reproducibly yielding smooth aminosilane monolayers. In this study, solution- and vapor-phase deposition methods for three aminoalkoxysilanes differing in the number of reactive groups (3-aminopropyl triethoxysilane (APTES), 3-aminopropyl methyl diethoxysilane (APMDES) and 3-aminopropyl dimethyl ethoxysilane (APDMES)) were assessed with the aim of identifying methods that yield highly uniform and reproducible silane layers that are resistant to minor procedural variations. Silane film quality was characterized based on measured thickness, hydrophilicity and surface roughness. Additionally, hydrolytic stability of the films was assessed via these thickness and contact angle values following desorption in water. We found that two simple solution-phase methods, an aqueous deposition of APTES and a toluene based deposition of APDMES, yielded high quality silane layers that exhibit comparable characteristics to those deposited via vapor-phase methods.
Collapse
Affiliation(s)
- Amrita R Yadav
- Department of Physics and Astronomy, University of Rochester, Rochester, NY, USA
| | - Rashmi Sriram
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, USA
| | | | - Benjamin L Miller
- Department of Biomedical Engineering, University of Rochester, Rochester, NY, USA; Department of Dermatology, University of Rochester, Rochester, NY, USA; Department of Biophysics and Biochemistry, University of Rochester, Rochester, NY, USA.
| |
Collapse
|
239
|
de Mel A, Ramesh B, Scurr DJ, Alexander MR, Hamilton G, Birchall M, Seifalian AM. Fumed Silica Nanoparticle Mediated Biomimicry for Optimal Cell-Material Interactions for Artificial Organ Development. Macromol Biosci 2013; 14:307-13. [DOI: 10.1002/mabi.201300382] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2013] [Revised: 09/20/2013] [Indexed: 11/10/2022]
Affiliation(s)
- Achala de Mel
- UCL Centre for Nanotechnology and Regenerative Medicine; University College London; London UK
- Division of Surgery and Interventional Science; London UK
| | - Bala Ramesh
- UCL Centre for Nanotechnology and Regenerative Medicine; University College London; London UK
- Division of Surgery and Interventional Science; London UK
| | - David J. Scurr
- Laboratory of Biophysics and Surface Analysis; School of Pharmacy; University of Nottingham; Nottingham NG7 2RD UK
| | - Morgan R. Alexander
- Laboratory of Biophysics and Surface Analysis; School of Pharmacy; University of Nottingham; Nottingham NG7 2RD UK
| | - George Hamilton
- Division of Surgery and Interventional Science; London UK
- Royal Free London NHS Foundation Trust Hospital; London UK
| | - Martin Birchall
- UCL Centre for Nanotechnology and Regenerative Medicine; University College London; London UK
- UCL Ear Institute; Royal National Throat; Nose and Ear Hospital; London UK
| | - Alexander M. Seifalian
- UCL Centre for Nanotechnology and Regenerative Medicine; University College London; London UK
- Division of Surgery and Interventional Science; London UK
- Royal Free London NHS Foundation Trust Hospital; London UK
| |
Collapse
|
240
|
Lee HK, Lee YH, Zhang Q, Phang IY, Tan JMR, Cui Y, Ling XY. Superhydrophobic surface-enhanced Raman scattering platform fabricated by assembly of Ag nanocubes for trace molecular sensing. ACS APPLIED MATERIALS & INTERFACES 2013; 5:11409-11418. [PMID: 24134617 DOI: 10.1021/am403655g] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
An analytical platform suitable for trace detection using a small volume of analyte is pertinent to the field of toxin detection and criminology. Plasmonic nanostructures provide surface-enhanced Raman scattering (SERS) that can potentially achieve trace toxins and/or molecules detection. However, the detection of highly diluted, small volume samples remains a challenge. Here, we fabricate a superhydrophobic SERS platform by assembling Ag nanocubes that support strong surface plasmon and chemical functionalization for trace detection with sample volume of just 1 μL. Our strategy integrates the intense electromagnetic field confinement generated by Ag nanocubes with a superhydrophobic surface capable of analyte concentration to lower the molecular detection limit. Single crystalline Ag nanocubes are assembled using the Langmuir-Blodgett technique to create surface roughness. To create a stable superhydrophobic SERS platform, an additional 25 nm Ag coating is evaporated over the Ag nanocubes to "weld" the Ag nanocubes onto the substrate followed by chemical functionalization with perfluorodecanethiol. The resulting substrate has an advancing contact angle of 169° ± 5°. Our superhydrophobic platform confines analyte molecules within a small area and prevents the random spreading of molecules. An analyte concentrating factor of 14-fold is attained, as compared to a hydrophilic surface. Consequently, the detection limit of our superhydrophobic SERS substrate reaches 10(-16) M (100 aM) for rhodamine 6G using 1 μL analyte solutions. An analytical SERS enhancement factor of 10(11) is achieved. Our protocol is a general method that provides a simple, cost-effective approach to develop a stable and uniform superhydrophobic SERS platform for trace molecular sensing.
Collapse
Affiliation(s)
- Hiang Kwee Lee
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University , Singapore 637371
| | | | | | | | | | | | | |
Collapse
|
241
|
Jakša G, Štefane B, Kovač J. XPS and AFM characterization of aminosilanes with different numbers of bonding sites on a silicon wafer. SURF INTERFACE ANAL 2013. [DOI: 10.1002/sia.5311] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- G. Jakša
- Jožef Stefan Institute; Jamova 39 SI-1000 Ljubljana Slovenia
| | - B. Štefane
- Faculty of Chemistry and Chemical Technology; Aškerčeva 5 SI-1000 Ljubljana Slovenia
| | - J. Kovač
- Jožef Stefan Institute; Jamova 39 SI-1000 Ljubljana Slovenia
- Centre of Excellence for Polymer Materials and Technologies-PoliMaT; Tehnološki park 24 1000 Ljubljana Slovenia
| |
Collapse
|
242
|
Li G, Zhang L, Wang C, Zhao X, Zhu C, Zheng Y, Wang Y, Zhao Y, Yang Y. Effect of silanization on chitosan porous scaffolds for peripheral nerve regeneration. Carbohydr Polym 2013; 101:718-26. [PMID: 24299831 DOI: 10.1016/j.carbpol.2013.09.064] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 09/16/2013] [Accepted: 09/18/2013] [Indexed: 11/25/2022]
Abstract
The aim of this study was to evaluate the feasibility of using 3-aminopropyltriethoxysilane (APTE) silanization treatment for modification and biocompatibility of lyophilized chitosan porous scaffolds. The process is beneficial for biomaterial development due to its low toxicity and simplicity. The silanization treatment with low APTE concentration showed no significant influence on the morphology of chitosan scaffolds, while a skin-like surface was observed for the silanized scaffolds treated with high APTE concentration. The porosity and surface amino densities were increased after silanization whereas the swelling ratio was reduced, and the degradation ratio in PBS and anti-acid degradation properties of the silanized chitosan scaffolds were significantly improved. The in vitro Schwann cells culture demonstrated that the silanized scaffolds with 8% APTE could obviously facilitate the attachment and proliferation of Schwann cells, indicating great potential for the application in peripheral nerve regeneration.
Collapse
Affiliation(s)
- Guicai Li
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Nantong 226001, PR China
| | | | | | | | | | | | | | | | | |
Collapse
|
243
|
Han X, Sun S, He T. Preparation and photolithography of self-assembled monolayers of 10-mercaptodecanylphosphonic acid on glass mediated by zirconium for protein patterning. Colloids Surf B Biointerfaces 2013; 108:66-71. [DOI: 10.1016/j.colsurfb.2013.02.030] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 02/02/2013] [Accepted: 02/05/2013] [Indexed: 12/22/2022]
|
244
|
Sakurai T, Takeda S, Takahashi JY, Takahashi Y, Wada N, Trirongjitmoah S, Namita T, Jin S, Ikuta A, Furumaki H, Hui SP, Fuda H, Fujikawa M, Shimizu K, Chiba H. Measurement of single low-density lipoprotein particles by atomic force microscopy. Ann Clin Biochem 2013; 50:564-70. [DOI: 10.1177/0004563213481586] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Background The size of lipoprotein particles is relevant to the risk of coronary artery disease (CAD). Methods We investigated the feasibility of atomic force microscopy (AFM) for evaluating the size of large low-density lipoprotein (LDL) and small dense LDL (sd-LDL) separated by ultracentrifugation. The measurements by AFM in tapping mode were compared to those by electron microscopy (EM). Results There was a significant difference in particle sizes determined by AFM between large LDL (20.6 ± 1.9 nm, mean ± SD) and sd-LDL (16.2 ± 1.4 nm) obtained from six healthy volunteers ( P < 0.05). The particle sizes determined by EM for the same samples were 23.2 ± 1.4 nm for large LDL and 20.4 ± 1.4 nm for sd-LDL. The difference between large LDL and sd-LDL detected by EM was also statistically significant ( P < 0.05). In addition, the particle sizes of each lipoprotein fraction were significantly different between AFM and EM: P < 0.05 for large LDL and P < 0.05 for sd-LDL. Conclusions AFM can differentiate between sd-LDL and large LDL particles by their size, and might be useful for evaluating risk for CAD.
Collapse
Affiliation(s)
| | - Seiji Takeda
- Faculty of Health Sciences, Hokkaido University, Sapporo, Japan
| | | | - Yuji Takahashi
- Faculty of Health Sciences, Hokkaido University, Sapporo, Japan
- Departments of Internal Medicine and Clinical Laboratory, Sapporo City General Hospital, Sapporo, Japan
| | - Norio Wada
- Departments of Internal Medicine and Clinical Laboratory, Sapporo City General Hospital, Sapporo, Japan
| | - Suchin Trirongjitmoah
- Graduate School of Information Science and Technology, Hokkaido University, Sapporo, Japan
| | - Takeshi Namita
- Graduate School of Information Science and Technology, Hokkaido University, Sapporo, Japan
| | - Shigeki Jin
- Faculty of Health Sciences, Hokkaido University, Sapporo, Japan
| | - Akiko Ikuta
- Faculty of Health Sciences, Hokkaido University, Sapporo, Japan
| | | | - Shu-Ping Hui
- Faculty of Health Sciences, Hokkaido University, Sapporo, Japan
| | - Hirotoshi Fuda
- Faculty of Health Sciences, Hokkaido University, Sapporo, Japan
| | - Masato Fujikawa
- Departments of Internal Medicine and Clinical Laboratory, Sapporo City General Hospital, Sapporo, Japan
| | - Koichi Shimizu
- Graduate School of Information Science and Technology, Hokkaido University, Sapporo, Japan
| | - Hitoshi Chiba
- Faculty of Health Sciences, Hokkaido University, Sapporo, Japan
| |
Collapse
|
245
|
Zhou H, Toney MF, Bent SF. Cross-Linked Ultrathin Polyurea Films via Molecular Layer Deposition. Macromolecules 2013. [DOI: 10.1021/ma400998m] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Han Zhou
- Department of Chemistry, Stanford University, Stanford, California 94305, United
States
| | - Michael F. Toney
- Stanford Synchrotron
Radiation
Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Stacey F. Bent
- Department of Chemical Engineering, Stanford University, Stanford, California 94305, United
States
| |
Collapse
|
246
|
Zhao Z, He Y, Yang H, Qu X, Lu X, Luo J. Aminosilanization nanoadhesive layer for nanoelectric circuits with porous ultralow dielectric film. ACS APPLIED MATERIALS & INTERFACES 2013; 5:6097-6107. [PMID: 23749192 DOI: 10.1021/am4009192] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
An ultrathin layer is investigated for its potential application of replacing conventional diffusion barriers and promoting interface adhesion for nanoelectric circuits with porous ultralow dielectrics. The porous ultralow dielectric (k ≈ 2.5) substrate is silanized by 3-aminopropyltrimethoxysilane (APTMS) to form the nanoadhesive layer by performing oxygen plasma modification and tailoring the silanization conditions appropriately. The high primary amine content is obtained in favor of strong interaction between amino groups and copper. And the results of leakage current measurements of metal-oxide-semiconductor capacitor structure demonstrate that the aminosilanization nanoadhesive layer can block copper diffusion effectively and guarantee the performance of devices. Furthermore, the results of four-point bending tests indicate that the nanoadhesive layer with monolayer structure can provide the satisfactory interface toughness up to 6.7 ± 0.5 J/m(2) for Cu/ultralow-k interface. Additionally, an annealing-enhanced interface toughness effect occurs because of the formation of Cu-N bonding and siloxane bridges below 500 °C. However, the interface is weakened on account of the oxidization of amines and copper as well as the breaking of Cu-N bonding above 500 °C. It is also found that APTMS nanoadhesive layer with multilayer structure provides relatively low interface toughness compared with monolayer structure, which is mainly correlated to the breaking of interlayer hydrogen bonding.
Collapse
Affiliation(s)
- Zhongkai Zhao
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | | | | | | | | | | |
Collapse
|
247
|
Treccani L, Yvonne Klein T, Meder F, Pardun K, Rezwan K. Functionalized ceramics for biomedical, biotechnological and environmental applications. Acta Biomater 2013; 9:7115-50. [PMID: 23567940 DOI: 10.1016/j.actbio.2013.03.036] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 03/21/2013] [Accepted: 03/23/2013] [Indexed: 12/12/2022]
Abstract
Surface functionalization has become of paramount importance and is considered a fundamental tool for the development and design of countless devices and engineered systems for key technological areas in biomedical, biotechnological and environmental applications. In this review, surface functionalization strategies for alumina, zirconia, titania, silica, iron oxide and calcium phosphate are presented and discussed. These materials have become particularly important concerning the aforementioned applications, being not only of great academic, but also of steadily increasing human and commercial, interest. In this review, special emphasis is given to their use as biomaterials, biosensors, biological targets, drug delivery systems, implants, chromatographic supports for biomolecule purification and analysis, and adsorbents for toxic substances and pollutants. The objective of this review is to provide a broad picture of the enormous possibilities offered by surface functionalization and to identify particular challenges regarding surface analysis and characterization.
Collapse
Affiliation(s)
- Laura Treccani
- University of Bremen, Advanced Ceramics, Am Biologischen Garten 2, 28359 Bremen, Germany.
| | | | | | | | | |
Collapse
|
248
|
Controlled silanization–amination reactions on the Ti6Al4V surface for biomedical applications. Colloids Surf B Biointerfaces 2013; 106:248-57. [DOI: 10.1016/j.colsurfb.2013.01.034] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Revised: 01/04/2013] [Accepted: 01/10/2013] [Indexed: 11/20/2022]
|
249
|
Tanaka M, Sawaguchi T, Kuwahara M, Niwa O. Surface modification of silicon oxide with trialkoxysilanes toward close-packed monolayer formation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:6361-6368. [PMID: 23668922 DOI: 10.1021/la4009834] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
In order to scrutinize potential of trialkoxysilanes to form close-packed monolayer, surface modification of silicon oxide was carried out with the trialkoxysilanes bearing a ferrocene moiety for analysis by electrochemical methods. As it was found that hydrogen-terminated silicon reacts with trialkoxysilane through natural oxidation in organic solvents, where the silicon oxide layer is thin enough to afford conductivity for electrochemical analysis, hydrogen-terminated silicon wafer was immersed in trialkoxysilane solution for surface modification without oxidation treatment. Cyclic voltammetry measurements to determine surface concentrations of the immobilized ferrocene-silane on silicon surface were carried out with various temperature, concentration, solvent, and molecular structure, while the blocking effect in the cyclic voltammogram was investigated to obtain insight into density leading to the close-packed layer. The results suggested that a monolayer modification tended to occur under milder conditions when the ferrocene-silane had a longer alkyl chain, and formation of a close-packed layer to show significant blocking effect was observed. However, the surface modification proceeded even when surface concentration of the immobilized ferrocene-silane was greater than that expected for the monolayer. On the basis of these tendencies, the surface of silicon oxide modified with trialkoxysilane is considered to be a partial multilayer rather than monolayer although a close-packed layer is formed. This result is supported by the comparison with carbon surface modified with ferrocene-diazonium, in which a significant blocking effect was observed when surface concentrations of the immobilized ferrocene moiety are lower than that for silicon oxide modified with ferrocene-silane.
Collapse
Affiliation(s)
- Mutsuo Tanaka
- Biomedical Research Institute, Advanced Industrial Science and Technology, Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan.
| | | | | | | |
Collapse
|
250
|
Ciofani G, Danti S, Genchi GG, Mazzolai B, Mattoli V. Boron nitride nanotubes: biocompatibility and potential spill-over in nanomedicine. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2013; 9:1672-1685. [PMID: 23423826 DOI: 10.1002/smll.201201315] [Citation(s) in RCA: 101] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 08/01/2012] [Indexed: 05/28/2023]
Abstract
Boron nitride nanotubes (BNNTs) represent an innovative and extremely intriguing class of nanomaterials. Thanks to their special chemical and physical characteristics, they have already found a large number of applications in the field of nanotechnology, and recent studies have shown their possible exploitation in the biomedical domain, both as nanocarriers and, more interestingly, as nanotransducers. In this review, the latest findings on the interactions between BNNTs and living systems are summarized, starting with the major issues of their stabilization in physiological media and their functionalization with bioactive molecules. Thereafter the biocompatibility data which have so far been made available are discussed, and the need for further extensive and standardized tests is highlighted. Finally, the appealing diagnostic and therapeutic opportunities offered by BNNT-based systems are described, envisioning the potential spill-over effects of such 'smart' and 'active' nanoparticles in nanomedicine.
Collapse
Affiliation(s)
- Gianni Ciofani
- Istituto Italiano di Tecnologia, Center for Micro-BioRobotics@SSSA, Viale Rinaldo Piaggio 34 Pontedera (Pisa) 56025, Italy.
| | | | | | | | | |
Collapse
|