scholarly journals Surface Structuring Combined with Chemical Surface Functionalization: An Effective Tool to Manipulate Cell Adhesion

Molecules ◽  
2019 ◽  
Vol 24 (5) ◽  
pp. 909 ◽  
Author(s):  
Sarah Elsayed ◽  
Stefan Paschke ◽  
Sibylle Rau ◽  
Karen Lienkamp
Keyword(s):  
Antimicrobial Activity ◽  
Cell Adhesion ◽  
Surface Structure ◽  
Resonance Spectroscopy ◽  
Structured Surfaces ◽  
Chemical Surface ◽  
Force Microscopy ◽  
Tissue Integration ◽  
Protein Adhesion ◽  
Escherichia Coli Bacteria

In this study, we investigate how a surface structure underneath a surface-attached polymer coating affects the bioactivity of the resulting material. To that end, structured surfaces were fabricated using colloidal lithography (lateral dimensions: 200 nm to 1 µm, height ~15 to 50 nm). The surface structures were further functionalized either with antimicrobial, cell-adhesive polycations or with protein-repellent polyzwitterions. The materials thus obtained were compared to non-functionalized structured surfaces and unstructured polymer monolayers. Their physical properties were studied by contact-angle measurements and atomic force microscopy (AFM). Protein adhesion was studied by surface plasmon resonance spectroscopy, and the antimicrobial activity against Escherichia coli bacteria was tested. The growth of human mucosal gingiva keratinocytes on the materials was analyzed using the Alamar blue assay, optical microscopy, and live-dead staining. The data shows that the underlying surface structure itself reduced protein adhesion and also bacterial adhesion, as evidenced by increased antimicrobial activity. It also enhanced cell adhesion to the surfaces. Particularly in combination with the adhesive polycations, the surfaces increased the cell growth compared to the unstructured reference materials. Thus, functionalizing structured surfaces with adhesive polymer could be a valuable tool for improved tissue integration.

scholarly journals Antibacterial Films Based on PVA and PVA–Chitosan Modified with Poly(Hexamethylene Guanidine)

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2093 ◽  
Author(s):  
Ewa Olewnik-Kruszkowska ◽  
Magdalena Gierszewska ◽  
Ewelina Jakubowska ◽  
Iwona Tarach ◽  
Vladimir Sedlarik ◽  
...  
Keyword(s):  
Polymeric Films ◽  
Attenuated Total Reflectance ◽  
Poly Vinyl Alcohol ◽  
Resonance Spectroscopy ◽  
Force Microscopy ◽  
Color Changes ◽  
Atomic Force ◽  
Escherichia Coli Bacteria ◽  
Thermal Stability Of ◽  
Biocidal Properties

In this study, thin, polymeric films consisting of poly(vinyl alcohol) (PVA) and chitosan (Ch) with the addition of poly(hexamethylene guanidine) (PHMG) were successfully prepared. The obtained materials were analyzed to determine their physicochemical and biocidal properties. In order to confirm the structure of PHMG, nuclear magnetic resonance spectroscopy (1H NMR) was applied, while in the case of the obtained films, attenuated total reflectance infrared spectroscopy with Fourier transform (FTIR-ATR) was used. The surface morphology of the polymer films was evaluated based on atomic force microscopy. Furthermore, the mechanical properties, color changes, and thermal stability of the obtained materials were determined. Microbiological tests were performed to evaluate the biocidal properties of the new materials with and without the addition of PHMG. These analyses confirmed the biocidal potential of films modified by PHMG and allowed for comparisons of their physicochemical properties with the properties of native films. In summary, films consisting of PVA and PHMG displayed higher antimicrobial potentials against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria in comparison to PVA:Ch-based films with the addition of PHMG.

Antimicrobial Activity of Silver Nanoparticles Synthesized by Streptomyces Species JF714876

2012 ◽  
Vol 5 (1) ◽  
pp. 1638-1642 ◽  
Author(s):  
Vidyasagar G M ◽  
Shankaravva B ◽  
R Begum ◽  
Imrose ◽  
Sagar R ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Silver Ions ◽  
Human Beings ◽  
Streptomyces Species ◽  
Force Microscopy ◽  
E Coli ◽  
Extracellular Synthesis ◽  
Atomic Force ◽  
Uv Visible

Microorganisms like fungi, actinomycetes and bacteria are considered nanofactories and are helpful in the production of nanoparticles useful in the welfare of human beings. In the present study, we investigated the production of silver nanoparticles from Streptomyces species JF714876. Extracellular synthesis of silver nanoparticles by Streptomyces species was carried out using two different media. Silver nanoparticles were examined using UV-visible, IR and atomic force microscopy. The size of silver nanoparticles was in the range of 80-100 nm. Antimicrobial activity of silver nanoparticle against bacteria such as E. coli, S. aureus, and dermatophytes like T. rubrum and T. tonsurans was determined. Thus, this study suggests that the Streptomyces sp. JF741876 can produce silver ions that can be used as an antimicrobial substance.

Image enhancement of polyethersulfone ultrafiltration membrane surface structure for atomic force microscopy

1992 ◽  
Vol 46 (1) ◽  
pp. 167-178 ◽  
Author(s):  
A. K. Fritzsche ◽  
A. R. Arevalo ◽  
M. D. Moore ◽  
C. J. Weber ◽  
V. B. Elings ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Surface Structure ◽  
Image Enhancement ◽  
Membrane Surface ◽  
Ultrafiltration Membrane ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals 1P030 Novel stable interactions between cell adhesion molecules detected using intermolecular force microscopy at sub-piconewton resolution

2004 ◽  
Vol 44 (supplement) ◽  
pp. S37
Author(s):  
Y. Tsukasaki ◽  
K. kitamura ◽  
K. Shimizu ◽  
A. H. Iwane ◽  
Y. Takai ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Adhesion Molecules ◽  
Cell Adhesion Molecules ◽  
Intermolecular Force ◽  
Force Microscopy

scholarly journals Surface structure of polymers and their model compounds observed by atomic force microscopy

1992 ◽  
Vol 42-44 ◽  
pp. 1141-1147 ◽  
Author(s):  
W. Stocker ◽  
B. Bickmann ◽  
S.N. Magonov ◽  
H.-J. Cantow ◽  
B. Lotz ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Surface Structure ◽  
Model Compounds ◽  
Force Microscopy ◽  
Atomic Force

Dynamics and metastable surface structure of double atomic layer of water molecules and ions at the interface between KBr(c) and water

2004 ◽  
Vol 76 (1) ◽  
pp. 115-122 ◽  
Author(s):  
K. Ichikawa ◽  
S. Sato ◽  
N. Shimomura
Keyword(s):  
Surface Structure ◽  
Vertical Motion ◽  
Atomic Layer ◽  
Water Molecules ◽  
Potassium Ions ◽  
Force Microscopy ◽  
Structure And Dynamics ◽  
Atomic Force ◽  
Bromide Ions

The metastable surface structure and dynamics of water molecules, cations, and anions at the interface between KBr(001) and water have been demonstrated from the images in situ observed in atomic resolution using atomic force microscopy. The vertical motion of potassium ions, which means their own transfer from the equilibrium sites to the upper height right on the underlying bromide ions, has been observed at the interface. They are used to be located in some steady state stabilized by their interaction with water molecules in the double atomic layer at the interface. The observed water molecules bridge two bromide ions by hydrogen bond; the water molecules are sandwiched by the potassium ions and vice versa.

scholarly journals The Physicochemical and Antibacterial Properties of Chitosan-Based Materials Modified with Phenolic Acids Irradiated by UVC Light

2021 ◽  
Vol 22 (12) ◽  
pp. 6472
Author(s):  
Beata Kaczmarek-Szczepańska ◽  
Marcin Wekwejt ◽  
Olha Mazur ◽  
Lidia Zasada ◽  
Anna Pałubicka ◽  
...  
Keyword(s):  
Thin Films ◽  
Antimicrobial Activity ◽  
Ferulic Acid ◽  
Phenolic Acid ◽  
Food Packaging ◽  
Antibacterial Properties ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After

This paper concerns the physicochemical properties of chitosan/phenolic acid thin films irradiated by ultraviolet radiation with wavelengths between 200 and 290 nm (UVC) light. We investigated the preparation and characterization of thin films based on chitosan (CTS) with tannic (TA), caffeic (CA) and ferulic acid (FA) addition as potential food-packaging materials. Such materials were then exposed to the UVC light (254 nm) for 1 and 2 h to perform the sterilization process. Different properties of thin films before and after irradiation were determined by various methods such as Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM), differential scanning calorimeter (DSC), mechanical properties and by the surface free energy determination. Moreover, the antimicrobial activity of the films and their potential to reduce the risk of contamination was assessed. The results showed that the phenolic acid improving properties of chitosan-based films, short UVC radiation may be used as sterilization method for those films, and also that the addition of ferulic acid obtains effective antimicrobial activity, which have great benefit for food packing applications.

Hierarchical Nano/Micro-structured Surfaces with High Surface Area/Volume Ratios

2021 ◽  
pp. 1-36
Author(s):  
Ketki Lichade ◽  
Yizhou Jiang ◽  
Yayue Pan
Keyword(s):  
Surface Structure ◽  
Surface Area ◽  
Light Trapping ◽  
High Surface ◽  
High Surface Area ◽  
Three Dimensional ◽  
Structure Design ◽  
Surface Structures ◽  
Structured Surfaces ◽  
Design And Manufacture

Abstract Recently, many studies have investigated additive manufacturing of hierarchical surfaces with high surface area/volume (SA/V) ratios, and their performance has been characterized for applications in next-generation functional devices. Despite recent advances, it remains challenging to design and manufacture high SA/V ratio structures with desired functionalities. In this study, we established the complex correlations among the SA/V ratio, surface structure geometry, functionality, and manufacturability in the Two-Photon Polymerization (TPP) process. Inspired by numerous natural structures, we proposed a 3-level hierarchical structure design along with the mathematical modeling of the SA/V ratio. Geometric and manufacturing constraints were modeled to create well-defined three-dimensional hierarchically structured surfaces with a high accuracy. A process flowchart was developed to design the proposed surface structures to achieve the target functionality, SA/V ratio, and geometric accuracy. Surfaces with varied SA/V ratios and hierarchy levels were designed and printed. The wettability and antireflection properties of the fabricated surfaces were characterized. It was observed that the wetting and antireflection properties of the 3-level design could be easily tailored by adjusting the design parameter settings and hierarchy levels. Furthermore, the proposed surface structure could change a naturally-hydrophilic surface to near-superhydrophobic. Geometrical light trapping effects were enabled and the antireflection property could be significantly enhanced (>80% less reflection) by the proposed hierarchical surface structures. Experimental results implied the great potential of the proposed surface structures for various applications such as microfluidics, optics, energy, and interfaces.

scholarly journals Lectins at Interfaces—An Atomic Force Microscopy and Multi-Parameter-Surface Plasmon Resonance Study

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2348 ◽  
Author(s):  
Katrin Niegelhell ◽  
Thomas Ganner ◽  
Harald Plank ◽  
Evelyn Jantscher-Krenn ◽  
Stefan Spirk
Keyword(s):  
Atomic Force Microscopy ◽  
Surface Plasmon Resonance ◽  
Protein Adsorption ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Resonance Spectroscopy ◽  
Carbohydrate Binding ◽  
Force Microscopy ◽  
Atomic Force ◽  
Slow Kinetics

Lectins are a diverse class of carbohydrate binding proteins with pivotal roles in cell communication and signaling in many (patho)physiologic processes in the human body, making them promising targets in drug development, for instance, in cancer or infectious diseases. Other applications of lectins employ their ability to recognize specific glycan epitopes in biosensors and glycan microarrays. While a lot of research has focused on lectin interaction with specific carbohydrates, the interaction potential of lectins with different types of surfaces has not been addressed extensively. Here, we screen the interaction of two specific plant lectins, Concanavalin A and Ulex Europaeus Agglutinin-I with different nanoscopic thin films. As a control, the same experiments were performed with Bovine Serum Albumin, a widely used marker for non-specific protein adsorption. In order to test the preferred type of interaction during adsorption, hydrophobic, hydrophilic and charged polymer films were explored, such as polystyrene, cellulose, N,-N,-N-trimethylchitosan chloride and gold, and characterized in terms of wettability, surface free energy, zeta potential and morphology. Atomic force microscopy images of surfaces after protein adsorption correlated very well with the observed mass of adsorbed protein. Surface plasmon resonance spectroscopy studies revealed low adsorbed amounts and slow kinetics for all of the investigated proteins for hydrophilic surfaces, making those resistant to non-specific interactions. As a consequence, they may serve as favorable supports for biosensors, since the use of blocking agents is not necessary.

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