Protein Adsorption on Detonation Nanodiamond/Polymer Composite Layers

2012 ◽  
Vol 1479 ◽  
pp. 51-56
Author(s):  
Lilyana D. Pramatarova ◽  
Todor A. Hikov ◽  
Natalia A. Krasteva ◽  
Peter Petrik ◽  
Raina P. Dimitrova ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Plasma Polymerization ◽  
Spatial Organization ◽  
Synergistic Effects ◽  
Uv Spectroscopy ◽  
Bacterial Colonization ◽  
Reference Sample ◽  
Structural Features ◽  
Detonation Nanodiamond ◽  
Composite Layers

ABSTRACTComposite layers of the detonation nanodiamond/polymer type possess a spatial organization of components with new structural features and physical properties, as well as complex functions due to the strong synergistic effects between the nanoparticles and polymer [1]. Composite layers were deposited by a plasma polymerization (PP) process of the detonation nanodiamond (DND) particles added to a hexamethyl disiloxan (HMDS) monomer [1]. The incorporation of silver ions in the polymer leads to the production of materials that are highly efficient against bacterial colonization and allows better cell adhesion and spreading. [2] For cell culture processes, fibronectin (FN) treatment is one of the commonly used approaches to enhance the cell adhesion on a surface [3].As an integrated part of our search for improved materials for life science applications such as biomaterials and biosensors, the objective of the present study is to investigate the interaction of Ag-based composite surfaces with FN protein. Two types of composite layers, Ag-ND/PPHMDS and Ag-nano/PPHMDS were obtained by plasma polymerization of HMDS and nanoparticles of Ag and Ag-DND. The composite layers are representative of the different incorporation of the Ag in the polymer net. The structures studied, consisting of composite layers with adsorbed FN were optically characterized with Ellipsometry, Fourier Transform Infrared (FTIR) and Ultra Violet (UV) Spectroscopy as well as by stylus profiling (Talysurf). The kinetic study of the FN adsorption indicates that the process depends on the FN concentration and the exposure time as well as on the surface chemistry of the composites. Compared to the reference sample, all composite layers exhibit an indication of a stronger ability to initiate the intrinsic pathway of coagulation.

scholarly journals Three-Dimensional Bone Substitutes for Oral and Maxillofacial Surgery: Biological and Structural Characterization

2018 ◽  
Vol 9 (4) ◽  
pp. 62 ◽  
Author(s):  
Gianluca Turco ◽  
Davide Porrelli ◽  
Eleonora Marsich ◽  
Federica Vecchies ◽  
Teresa Lombardi ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Clinical Performance ◽  
Maxillofacial Surgery ◽  
Chemical Characterization ◽  
Bone Substitutes ◽  
Human Cell Line ◽  
Structural Features ◽  
Oral And Maxillofacial Surgery ◽  
Cell Adhesion And Proliferation

Background: Bone substitutes, either from human (autografts and allografts) or animal (xenografts) sources, suffer from inherent drawbacks including limited availability or potential infectivity to name a few. In the last decade, synthetic biomaterials have emerged as a valid alternative for biomedical applications in the field of orthopedic and maxillofacial surgery. In particular, phosphate-based bone substitution materials have exhibited a high biocompatibility due to their chemical similitude with natural hydroxyapatite. Besides the nature of the biomaterial, its porous and interconnected architecture is essential for a correct osseointegration. This performance could be predicted with an extensive characterization of the biomaterial in vitro. Methods: In this study, we compared the biological, chemical, and structural features of four different commercially available bone substitutes derived from an animal or a synthetic source. To this end, µ-CT and SEM were used to describe the biomaterials structure. Both FTIR and EDS analyses were carried out to provide a chemical characterization. The results obtained by these techniques were correlated with cell adhesion and proliferation of the osteosarcoma MG-63 human cell line cultured in vitro. Results: The findings reported in this paper indicate a significant influence of both the nature and the structure of the biomaterials in cell adhesion and proliferation, which ultimately could affect the clinical performance of the biomaterials. Conclusions: The four commercially available bone substitutes investigated in this work significantly differed in terms of structural features, which ultimately influenced in vitro cell proliferation and may so affect the clinical performance of the biomaterials.

scholarly journals Controlled spatial organization of bacterial clusters reveals cell filamentation is vital for Xylella fastidiosa biofilm formation

2021 ◽  
Author(s):  
Silambarasan Anbumani ◽  
Aldeliane M. da Silva ◽  
Eduarda R. Fischer ◽  
Mariana de Souza e Silva ◽  
Antonio A.G. von Zuben ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Quorum Sensing ◽  
Biofilm Formation ◽  
Spatial Organization ◽  
Xylella Fastidiosa ◽  
Cell Formation ◽  
Formation Mechanisms ◽  
Cell Morphogenesis ◽  
Cell Clusters ◽  
Filamentous Cell

The morphological plasticity of bacteria to form filamentous cells commonly represents an adaptive strategy induced by stresses. In contrast, for diverse pathogens filamentous cells have been observed during biofilm formation, with function yet to be elucidated. To identify prior hypothesized quorum sensing as trigger of such cell morphogenesis, spatially controlled cell adhesion is pivotal. Here, we demonstrate highly-selective cell adhesion of the biofilm-forming phytopathogen Xylella fastidiosa to gold-patterned SiO2 substrates with well-defined geometries and dimensions. The consequent control of both cell density and distances between cell clusters using these patterns provided evidence of quorum sensing governing filamentous cell formation. While cell morphogenesis is induced by cell cluster density, filamentous cell growth is oriented towards neighboring cell clusters and distance-dependent; large interconnected cell clusters create the early biofilm structural framework. Together, our findings and investigative platform could facilitate therapeutic developments targeting biofilm formation mechanisms of X. fastidiosa and other pathogens.

scholarly journals Porous ZnO/Co3O4/N-doped carbon nanocages synthesized via pyrolysis of complex metal–organic framework (MOF) hybrids as an advanced lithium-ion battery anode

2019 ◽  
Vol 75 (7) ◽  
pp. 969-978 ◽  
Author(s):  
Erbo Cheng ◽  
Shoushuang Huang ◽  
Dayong Chen ◽  
Ruting Huang ◽  
Qing Wang ◽  
...  
Keyword(s):  
Metal Oxides ◽  
Synergistic Effects ◽  
Metal Organic Framework ◽  
Lithium Ion ◽  
Reversible Capacity ◽  
Structural Features ◽  
High Rate ◽  
Discharge Process ◽  
Retention Capacity ◽  
Metal Organic

Metal oxides have a large storage capacity when employed as anode materials for lithium-ion batteries (LIBs). However, they often suffer from poor capacity retention due to their low electrical conductivity and huge volume variation during the charge–discharge process. To overcome these limitations, fabrication of metal oxides/carbon hybrids with hollow structures can be expected to further improve their electrochemical properties. Herein, ZnO-Co3O4 nanocomposites embedded in N-doped carbon (ZnO-Co3O4@N-C) nanocages with hollow dodecahedral shapes have been prepared successfully by the simple carbonizing and oxidizing of metal–organic frameworks (MOFs). Benefiting from the advantages of the structural features, i.e. the conductive N-doped carbon coating, the porous structure of the nanocages and the synergistic effects of different components, the as-prepared ZnO-Co3O4@N-C not only avoids particle aggregation and nanostructure cracking but also facilitates the transport of ions and electrons. As a result, the resultant ZnO-Co3O4@N-C shows a discharge capacity of 2373 mAh g−1 at the first cycle and exhibits a retention capacity of 1305 mAh g−1 even after 300 cycles at 0.1 A g−1. In addition, a reversible capacity of 948 mAh g−1 is obtained at a current density of 2 A g−1, which delivers an excellent high-rate cycle ability.

scholarly journals Dynamic switching enables efficient bacterial colonization in flow

2018 ◽  
Vol 115 (21) ◽  
pp. 5438-5443 ◽  
Author(s):  
Anerudh Kannan ◽  
Zhenbin Yang ◽  
Minyoung Kevin Kim ◽  
Howard A. Stone ◽  
Albert Siryaporn
Keyword(s):  
Mammalian Cells ◽  
Spatial Organization ◽  
Dynamic Instability ◽  
Bacterial Colonization ◽  
Cell Types ◽  
Search Space ◽  
Flow Networks ◽  
Surface Attachment ◽  
Dynamic Switching ◽  
Two Phases

Bacteria colonize environments that contain networks of moving fluids, including digestive pathways, blood vasculature in animals, and the xylem and phloem networks in plants. In these flow networks, bacteria form distinct biofilm structures that have an important role in pathogenesis. The physical mechanisms that determine the spatial organization of bacteria in flow are not understood. Here, we show that the bacteriumP. aeruginosacolonizes flow networks using a cyclical process that consists of surface attachment, upstream movement, detachment, movement with the bulk flow, and surface reattachment. This process, which we have termed dynamic switching, distributes bacterial subpopulations upstream and downstream in flow through two phases: movement on surfaces and cellular movement via the bulk. The model equations that describe dynamic switching are identical to those that describe dynamic instability, a process that enables microtubules in eukaryotic cells to search space efficiently to capture chromosomes. Our results show that dynamic switching enables bacteria to explore flow networks efficiently, which maximizes dispersal and colonization and establishes the organizational structure of biofilms. A number of eukaryotic and mammalian cells also exhibit movement in two phases in flow, which suggests that dynamic switching is a modality that enables efficient dispersal for a broad range of cell types.

scholarly journals Structure of the chicken neuron-glia cell adhesion molecule, Ng-CAM: origin of the polypeptides and relation to the Ig superfamily.

1991 ◽  
Vol 112 (5) ◽  
pp. 1017-1029 ◽  
Author(s):  
M P Burgoon ◽  
M Grumet ◽  
V Mauro ◽  
G M Edelman ◽  
B A Cunningham
Keyword(s):  
Cell Adhesion ◽  
Adhesion Molecule ◽  
Cell Adhesion Molecule ◽  
Single Gene ◽  
Structural Features ◽  
Cdna Clones ◽  
Glia Cell ◽  
Type Iii ◽  
Amino Terminal ◽  
Extracellular Region

The neuron-glia cell adhesion molecule (Ng-CAM) mediates both neuron-neuron and neuron-glia adhesion; it is detected on SDS-PAGE as a predominant 135-kD glycoprotein, with minor components of 80, 190, and 210 kD. We have isolated cDNA clones encoding the entire sequence of chicken Ng-CAM. The predicted extracellular region includes six immunoglobulin-like domains followed by five fibronectin-type III repeats, structural features that are characteristic of several neural CAMs of the N-CAM superfamily. The amino acid sequence of chicken Ng-CAM is most similar to that of mouse L1 but the overall identity is only 40% and Ng-CAM contains a short fibronectin-like segment with an RGD sequence that has no counterpart in L1. These findings suggest that Ng-CAM and L1 may not be equivalent molecules in chicken and mouse. The amino-terminal sequences of the 210-, 190-, and 135-kD components of Ng-CAM are all the same as the predicted amino terminus of the molecule, whereas the 80-kD component begins within the third fibronectin repeat. The cDNA sequence is continuous across the junction between the 135- and 80-kD components, and a single 170-kD Ng-CAM polypeptide was isolated from tunicamycin-treated cells. In addition, all cDNA probes hybridized on Northern blots to a 6-kb RNA, and most hybridized to single bands on Southern blots. These results indicate that the Ng-CAM components are derived from a single polypeptide encoded by a single gene, and that the 135- and 80-kD components are generated from the 210/190-kD species by proteolytic cleavage. The 135-kD component contains most of the extracellular region including all of the immunoglobulin-like domains. It has no transmembrane segment, but it is tightly associated with the membrane. The 80-kD component contains two and a half type III repeats plus the RGD-containing segment, as well as the single transmembrane and cytoplasmic domains. These structural features of Ng-CAM provide a framework for understanding its multiple functions in neuron-neuron interactions, neurite fasciculation, and neuron-glia interactions.

A "trimurti" heterostructured hybrid with an intimate CoO/CoxP interface as a robust bifunctional air electrode for rechargeable Zn–air batteries

2020 ◽  
Vol 8 (18) ◽  
pp. 9177-9184 ◽  
Author(s):  
Yue Niu ◽  
Meiling Xiao ◽  
Jianbing Zhu ◽  
Taotao Zeng ◽  
Jingde Li ◽  
...  
Keyword(s):  
Synergistic Effects ◽  
Catalytic Efficiency ◽  
Structural Features ◽  
Air Electrode ◽  
Bifunctional Air Electrode

The synergistic effects of triphasic cobalt-based nanoparticles andtheir superior structural features enable unprecedented bifunctional catalytic efficiency and durability.

scholarly journals Structural features of the fly chromatin colors revealed by automatic three-dimensional modeling.

2016 ◽  
Author(s):  
François Serra ◽  
Davide Baù ◽  
Guillaume Filion ◽  
Marc A. Marti-Renom
Keyword(s):  
Spatial Organization ◽  
Three Dimensional ◽  
Structural Features ◽  
Three Dimensions ◽  
Chromosome Conformation ◽  
Three Dimensional Modeling ◽  
Genomic Technologies ◽  
A Genome ◽  
Contact Data ◽  
Three Dimensional Models

The sequence of a genome is insufficient to understand all genomic processes carried out in the cell nucleus. To achieve this, the knowledge of its three- dimensional architecture is necessary. Advances in genomic technologies and the development of new analytical methods, such as Chromosome Conformation Capture (3C) and its derivatives, now permit to investigate the spatial organization of genomes. However, inferring structures from raw contact data is a tedious process for shortage of available tools. Here we present TADbit, a computational framework to analyze and model the chromatin fiber in three dimensions. To illustrate the use of TADbit, we automatically modeled 50 genomic domains from the fly genome revealing differential structural features of the previously defined chromatin colors, establishing a link between the conformation of the genome and the local chromatin composition. More generally, TADbit allows to obtain three-dimensional models ready for visualization from 3C-based experiments and to characterize their relation to gene expression and epigenetic states. TADbit is open-source and available for download from http://www.3DGenomes.org.

scholarly journals Efficient differentiation and polarization of primary cultured neurons on poly(lactic acid) scaffolds with microgrooved structures

2019 ◽  
Author(s):  
Asako Otomo ◽  
Mahoko Takahashi Ueda ◽  
Toshinori Fujie ◽  
Arihiro Hasebe ◽  
Yosuke Okamura ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Cell Adhesion ◽  
Cortical Neurons ◽  
Molecular Mechanisms ◽  
Cultured Cells ◽  
Structural Features ◽  
Poly Lactic Acid ◽  
Adhesion Properties ◽  
Expression Of Genes ◽  
Cultured Cortical Neurons

AbstractSynthetic biodegradable polymers including poly(lactic acid) (PLA) are attractive cell culture substrates because their surfaces can be micropatterned to support cell adhesion. The cell adhesion properties of a scaffold mainly depend on its surface chemical and structural features; however, it remains unclear how these characteristics affect the growth and differentiation of cultured cells or their gene expression. In this study, we fabricated two differently structured PLA nanosheets: flat and microgrooved. We assessed the growth and differentiation of mouse primary cultured cortical neurons on these two types of nanosheets after pre-coating with poly-D-lysine and vitronectin. Interestingly, prominent neurite bundles were formed along the grooves on the microgrooved nanosheets, whereas thin and randomly extended neurites were only observed on the flat nanosheets. Comparative RNA sequencing analyses revealed that the expression of genes related to postsynaptic density, dendritic shafts, and asymmetric synapses was significantly and consistently up-regulated in cells cultured on the microgrooved nanosheets when compared with those cultured on the flat nanosheets. These results indicate that microgrooved PLA nanosheets can provide a powerful means of establishing a culture system for the efficient and reproducible differentiation of neurons, which will facilitate future investigations of the molecular mechanisms underlying the pathogenesis of neurological disorders.

scholarly journals Dentin Priming with Amphipathic Antimicrobial Peptides

2019 ◽  
Vol 98 (10) ◽  
pp. 1112-1121 ◽  
Author(s):  
D.G. Moussa ◽  
J.A. Kirihara ◽  
Z. Ye ◽  
N.G. Fischer ◽  
J. Khot ◽  
...  
Keyword(s):  
Antimicrobial Peptides ◽  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Second Harmonic ◽  
Artificial Saliva ◽  
Bacterial Colonization ◽  
Structural Features ◽  
Water Repellent ◽  
Dentinal Tubules ◽  
Dentin Conditioning

The evolution of bonded restorations has undergone great progress over several decades. Nonetheless, life spans of bonded restorations are limited mainly because of the eventual incidence of recurrent caries. Over time, water and waterborne agents (acids, enzymes) degrade the components of the dentin/restoration interface, allowing bacterial colonization and dentin reinfection at the margins of the restoration. We developed a 2-tier protective technology consisting of priming/coating dentin with amphipathic and antimicrobial peptides (AAMPs) to obtain hydrophobic/water-repellent and antibiofilm dentin-resisting recurrent caries around bonded restorations. We tested a series of AAMPs to assess their structure-function relationships as well as the effects of different dentin-conditioning methods on the structural features of AAMP-coated dentin. We found relation between the secondary structure of AAMPs (high portion of β-sheet), the antimicrobial potency of AAMPs, and the AAMPs’ ability to form hydrophobic coatings on dentin. We also determined that AAMPs had preferential adsorption on the mineral phase of dentin, which suggested that peptides arrange their cationic and hydrophilic motifs in direct contact with the negatively charged minerals in the hydrophilic dentin. These results led us to explore different dentin-conditioning methods that would increase the mineral/collagen ratio and their effect on AAMP immobilization. We innovatively imaged the spatial distribution of the AAMPs in relation to the dentinal tubules and collagen network using a minimally invasive multimodal imaging technique: multiphoton–second harmonic generation. Using multiphoton–second harmonic generation imaging, we determined that partial deproteinization of dentin increased the amount of immobilized AAMPs as compared with the total etched dentin at the dentin surface and extended deeply around dentinal tubules. Last, we analyzed the release rate of AAMPs from dentin coatings in artificial saliva to predict their stability in the clinical setting. In conclusion, priming dentin with AAMPs is a versatile new approach with potential to fortify the otherwise vulnerable adhesive-based interfaces.

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