scholarly journals Direct Experimental Evidence of Biomimetic Surfaces with Chemical Modifications Interfering with Adhesive Protein Adsorption

Molecules ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 27 ◽  
Author(s):  
Hui Yang ◽  
Wei Zhang ◽  
Ting Chen ◽  
Shizhe Huang ◽  
Baogang Quan ◽  
...  
Keyword(s):  
Basic Research ◽  
Monitoring Method ◽  
Force Microscopy ◽  
Biomimetic Surfaces ◽  
Marine Biofouling ◽  
Atomic Force ◽  
Functionalized Surfaces ◽  
Single Method ◽  
New Perspective ◽  
Adhesive Proteins

Current approaches to dealing with the worldwide problem of marine biofouling are to impart chemical functionality to the surface or utilize microtopography inspired by nature. Previous reports have shown that only introducing a single method may not resist adhesion of mussels or inhibit biofouling in static forms. While it is promising to integrate two methods to develop an effective antifouling strategy, related basic research is still lacking. Here, we have fabricated engineered shark skin surfaces with different feature heights and terminated with different chemical moieties. Atomic force microscopy (AFM) with a modified colloid probe technique and quartz crystal microbalance with a dissipation n (QCM-D) monitoring method have been introduced to directly determine the interactions between adhesive proteins and functionalized surfaces. Our results indicate that the adhesion strength of probe-surface decreases with increasing feature height, and it also decreases from bare Si surface to alkyl and hydroxyl modification, which is attributed to different contact area domains and interaction mechanisms. Combining biomimetic microtopography and surface chemistry, our study provides a new perspective for designing and developing underwater anti-fouling materials.

scholarly journals Hydrophilic Silver Nanoparticles Loaded into Niosomes: Physical–Chemical Characterization in View of Biological Applications

Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1177 ◽  
Author(s):  
Federica Rinaldi ◽  
Elena del Favero ◽  
Johannes Moeller ◽  
Patrizia Nadia Hanieh ◽  
Daniele Passeri ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Human Serum ◽  
Nile Red ◽  
Chemical Characterization ◽  
Entrapment Efficiency ◽  
Tween 20 ◽  
Biological Applications ◽  
Force Microscopy ◽  
Atomic Force ◽  
New Perspective

Silver nanoparticles (AgNPs) are widely used as antibacterial agents and anticancer drugs, but often their low stability limits their mass production and broad applications. The use of niosomes as a carrier to protect and envelop AgNPs gives a new perspective to solve these problems. In this study, AgNPs were functionalized with sodium 3-mercapto-1-propanesulfonate (3MPS) to induce hydrophilic behavior, improving loading in Tween 20 and Span 20 niosomes (NioTw20 and NioSp20, respectively). Entrapment efficiency was evaluated by UV analyses and is around 1–4%. Dimensions were investigated by means of dynamic light scattering (DLS) (<2RH> = 140 ± 4 nm and <2RH> = 251 ± 1 nm respectively for NioTw20 + AgNPs and NioSp20 + AgNPs) and were compared with those by atomic force microscopy (AFM) and small angle X ray scattering (SAXS) analyses. Stability was assessed in water up to 90 days, and both in bovine serum and human serum for up to 8 h. In order to characterize the local structure of niosomes, SAXS measurements have been performed on Tween 20 and Span 20 empty niosomes and loaded with AgNPs. The release profiles of hydrophilic probe calcein and lipophilic probe Nile Red were performed in HEPES buffer and in human serum. All these features contribute to conclude that the two systems, NioTw20 + AgNPs and NioSp20 + AgNPs, are suitable and promising in the field of biological applications.

AFM Integrated with SEM and FIB: A Synergistic Union

2013 ◽  
Vol 21 (6) ◽  
pp. 26-31
Author(s):  
Aaron Lewis ◽  
A. Komissar ◽  
A. Ignatov ◽  
Oleg Fedoroyov ◽  
E. Maayan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Atomic Force Microscopy ◽  
Research And Development ◽  
Scientific Community ◽  
Ion Beam ◽  
Basic Research ◽  
Force Microscopy ◽  
Atomic Force ◽  
Scanning Electron

Scanning electron microscopy (SEM) and ion beam milling techniques are mature nanoscale measurement technologies, whereas atomic force microscopy (AFM) is a developing technology generating intense interest in the scientific community for basic research and development. These techniques have generally existed in separate worlds. This article discusses a capability that marries these technologies through an instrument recently introduced by Nanonics, the 3TB4000.

Preparation of Cu(In,Ga)Se2 thin films at low substrate temperatures

2001 ◽  
Vol 16 (2) ◽  
pp. 394-399 ◽  
Author(s):  
S. Nishiwaki ◽  
T. Satoh ◽  
Y. Hashimoto ◽  
T. Negami ◽  
T. Wada
Keyword(s):  
Thin Films ◽  
Surface Composition ◽  
Soda Lime ◽  
Soda Lime Glass ◽  
X Ray Diffraction ◽  
Monitoring Method ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Substrate Temperatures

Cu(In,Ga)Se2(CIGS) thin films were prepared at substrate temperatures of 350 to 500 °C. The (In,Ga)2Se2 precursor layers were deposited on Mo coated soda-lime glass and then exposed to Cu and Se fluxes to form CIGS films. The surface composition was probed by a real-time composition monitoring method. The CIGS films were characterized by x-ray diffraction, energy dispersive x-ray spectroscopy, secondary ion mass spectroscopy, and atomic force microscopy. The transient formation of a Cu–Se phase with a high thermal emissivity was observed during the deposition of Cu and Se at a substrate temperature of 350 °C. Faster diffusion of In than Ga from the (In,Ga)2Se3 precursor to the newly formed CIGS layer was observed. A growth model for CIGS films during the deposition of Cu and Se onto (In,Ga)2Se3 precursor is proposed. A solar cell using a CIGS film prepared at about 350 °C showed an efficiency of 12.4%.

scholarly journals Microtopography of the eye surface of the crab Carcinus maenas : an atomic force microscope study suggesting a possible antifouling potential

2013 ◽  
Vol 10 (84) ◽  
pp. 20130122 ◽  
Author(s):  
G. Greco ◽  
T. Svaldo Lanero ◽  
S. Torrassa ◽  
R. Young ◽  
M. Vassalli ◽  
...  
Keyword(s):  
Power Plants ◽  
Organic Molecules ◽  
Carcinus Maenas ◽  
Force Microscopy ◽  
Marine Biofouling ◽  
Sensor Model ◽  
Atomic Force ◽  
Fouling Release ◽  
Release Potential ◽  
Insight Into

Marine biofouling causes problems for technologies based on the sea, including ships, power plants and marine sensors. Several antifouling techniques have been applied to marine sensors, but most of these methodologies are environmentally unfriendly or ineffective. Bioinspiration, seeking guidance from natural solutions, is a promising approach to antifouling. Here, the eye of the green crab Carcinus maenas was regarded as a marine sensor model and its surface characterized by means of atomic force microscopy. Engineered surface micro- and nanotopography is a new mechanism found to limit biofouling, promising an effective solution with much reduced environmental impact. Besides giving a new insight into the morphology of C. maenas eye and its characterization, our study indicates that the eye surface probably has antifouling/fouling-release potential. Furthermore, the topographical features of the surface may influence the wettability properties of the structure and its interaction with organic molecules. Results indicate that the eye surface micro- and nanotopography may lead to bioinspired solutions to antifouling protection.

Biocompatibility Assessment of SiC Surfaces After Functionalization with Self Assembled Organic Monolayers

2009 ◽  
Vol 1235 ◽  
Author(s):  
Alexandra Oliveros ◽  
Sebastian J. Schoell ◽  
Christopher Frewin ◽  
Marco Hoeb ◽  
Martin Stutzmann ◽  
...  
Keyword(s):  
Hydrophobic Surface ◽  
Force Microscopy ◽  
Pheochromocytoma Cells ◽  
Hydrophilic Surfaces ◽  
Atomic Force ◽  
Functionalized Surfaces ◽  
Diphenyltetrazolium Bromide ◽  
Covalent Grafting ◽  
Assembled Monolayers ◽  
Self Assembled

AbstractThe biocompatibility of 6H-SiC (0001) surfaces was increased by more than a factor of six through the covalent grafting of NH2 terminated self-assembled monolayers (SAM) using APDEMS and APTES molecules. Surface functionalization began with a hydroxyl, OH, surface termination. The study included two NH2 terminated surfaces obtained through silanization with APDEMS (aminopropyldiethoxymethylsilane) and APTES (aminopropyltriethoxysilane) molecules (hydrophilic surfaces) and a CH3 terminated surface produced via alkylation with 1-octadecene (hydrophobic surface). H4 human neuroglioma and PC12 rat pheochromocytoma cells were seeded on the functionalized surfaces and the cell morphology was evaluated with atomic force microscopy (AFM). In addition, 96 hour MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays were employed to evaluate the cell viability on the SAM modified samples. The biocompatibility was enhanced with a 2 fold (171-240%) increase with 1-octadecene, 3-6 fold (320-670%) increase with APDEMS and 5-8 fold (476-850%) increase with APTES with respect to untreated 6H-SiC surfaces.

Simulation of Micromechanical Measurement of Mass Accretion: Quantifying the Importance of Material Selection and Geometry on Performance

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
Michael James Martin
Keyword(s):  
Natural Frequency ◽  
System Performance ◽  
Elastic Moduli ◽  
Material Selection ◽  
Optimal Thickness ◽  
Force Microscopy ◽  
Atomic Force ◽  
Functionalized Surfaces ◽  
Silicon Cantilever ◽  
Afm Cantilever

Micro- and nanomechanical resonators operating in liquid have been used to measure the change in the mass of either cells or functionalized surfaces attached to the resonator. As the system accretes mass, the natural frequency of the system changes, which can be measured experimentally. The current work extends methods previously developed for simulation of an atomic force microscope operating in liquid to study this phenomenon. A silicon cantilever with a 10 micron width, an 800 nm thickness, and a length of 30 microns was selected as a baseline configuration. The change in resonant frequency as the system accretes mass was determined through simulation. The results show that the change in natural frequency as mass accretes on the resonator is predictable through simulation. The geometry and material of the cantilever were varied to optimize the system. The results show that shorter cantilevers yield large gains in system performance. The width does not have a large impact on the system performance. Selecting the optimal thickness requires balancing the increase in overall system mass with the improvement in frequency response as the structure becomes thicker. Because there is no limit to the maximum system stiffness, the optimal materials will be those with higher elastic moduli. Based on these criteria, the optimum resonator for mass accretion measurements will be significantly different than an optimized atomic-force microscopy (AFM) cantilever.

Functionalized Waveguides for Biological Assays

2006 ◽  
Vol 950 ◽  
Author(s):  
Aaron S. Anderson ◽  
Andrew M. Dattelbaum ◽  
Gabriel A. Montaño ◽  
Jurgen G. Schmidt ◽  
Jennifer S. Martinez ◽  
...  
Keyword(s):  
Self Assembly ◽  
Protective Antigen ◽  
Specific Binding ◽  
Biological Assays ◽  
Force Microscopy ◽  
Sensing Applications ◽  
Angle Measurements ◽  
Atomic Force ◽  
Functionalized Surfaces ◽  
Contact Angle Measurements

ABSTRACTWe report here a procedure for the functioalization of SiO2-coated, SiONx waveguides for biological assays. Surface functionalization occurs by self-assembly of an amine-terminated silane monolayer on the waveguide, followed by partial chemical modification with functionalized polyethylene glycol (PEG) groups. Functionalized surfaces were characterized by atomic force microscopy and contact angle measurements. When combined with a BSA blocking step, these functional PEG surfaces significantly reduced non-specific binding and allowed for specific binding to occur. An antibody sandwich assay for detection of Bacillus anthracis protective antigen was used to validate these surfaces for sensing applications.

Atomic force microscopy studies of generation 4 poly(amidoamine) (PAMAM) dendrimers on functionalized surfaces

2004 ◽  
Vol 558 (1-3) ◽  
pp. 99-110 ◽  
Author(s):  
Hosam G. Abdelhady ◽  
Stephanie Allen ◽  
Martyn C. Davies ◽  
Clive J. Roberts ◽  
Saul J.B. Tendler ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Pamam Dendrimers ◽  
Force Microscopy ◽  
Atomic Force ◽  
Functionalized Surfaces

scholarly journals Biomimetic Surfaces via Dextran Immobilization: Grafting Density and Surface Properties

2004 ◽  
Vol 826 ◽  
Author(s):  
Davide Miksa ◽  
Elizabeth R. Irish ◽  
Dwayne Chen ◽  
Russell J. Composto ◽  
David M. Eckmann
Keyword(s):  
Contact Angle ◽  
Surface Oxidation ◽  
Sodium Metaperiodate ◽  
Oxidized Dextran ◽  
Force Microscopy ◽  
Biomimetic Surfaces ◽  
H Nmr ◽  
Atomic Force ◽  
Angle Data ◽  
Contact Angle Analysis

AbstractBiomimetic surfaces were prepared by chemisorption of oxidized dextran (Mw = 110 kDa) onto SiO2 substrates that were previously modified with aminopropyl-tri-ethoxy silane (APTES). The kinetics of dextran oxidation by sodium metaperiodate (NaIO4) were quantified by 1H NMR and pH measurements. The extent of oxidation was then used to control the morphology of the biomimetic surface. Oxidation times of 0.5, 1, 2, 4, and 24 hours resulted in <20, ∼30, ∼40, ∼50 and 100% oxidation, respectively. The surfaces were characterized by contact angle analysis and atomic force microscopy (AFM). Surfaces prepared with low oxidation times revealed a more densely packed “brushy” layer when imaged by AFM than those prepared at low oxidation times. Finally, the contact angle data revealed, quite unexpectedly, that the surface with the greatest entropic freedom (0.5 h) wetted the fastest and to the greatest extent (θAPTES>θ1h>θ2,4h>θ0.5h).

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