Layer-by-Layer Assemblies of Catechol-Functionalized TiO2Nanoparticles and Porphyrins through Electrostatic Interactions

2015 ◽  
Vol 21 (13) ◽  
pp. 5041-5054 ◽  
Author(s):  
Alexandra Burger ◽  
Rubén D. Costa ◽  
Volodymyr Lobaz ◽  
Wolfgang Peukert ◽  
Dirk M. Guldi ◽  
...  
Keyword(s):  
Electrostatic Interactions ◽  
Layer By Layer

scholarly journals Decomposition of Glucose-Sensitive Layer-by-Layer Films Using Hemin, DNA, and Glucose Oxidase

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 319 ◽  
Author(s):  
Kentaro Yoshida ◽  
Yu Kashimura ◽  
Toshio Kamijo ◽  
Tetsuya Ono ◽  
Takenori Dairaku ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Glucose Oxidase ◽  
Dna Cleavage ◽  
Electrostatic Interactions ◽  
Glucose Solution ◽  
Layer By Layer ◽  
Sensitive Layer ◽  
Physiological Conditions ◽  
Lbl Films ◽  
Low Glucose

Glucose-sensitive films were prepared through the layer-by-layer (LbL) deposition of hemin-modified poly(ethyleneimine) (H-PEI) solution and DNA solution (containing glucose oxidase (GOx)). H-PEI/DNA + GOx multilayer films were constructed using electrostatic interactions. The (H-PEI/DNA + GOx)5 film was then partially decomposed by hydrogen peroxide (H2O2). The mechanism for the decomposition of the LbL film was considered to involve more reactive oxygen species (ROS) that were formed by the reaction of hemin and H2O2, which then caused nonspecific DNA cleavage. In addition, GOx present in the LbL films reacts with glucose to generate hydrogen peroxide. Therefore, decomposition of the (H-PEI/DNA + GOx)5 film was observed when the thin film was immersed in a glucose solution. (H-PEI/DNA + GOx)5 films exposed to a glucose solution for periods of 24, 48 72, and 96 h indicated that the decomposition of the film increased with the time to 9.97%, 16.3%, 23.1%, and 30.5%, respectively. The rate of LbL film decomposition increased with the glucose concentration. At pH and ionic strengths close to physiological conditions, it was possible to slowly decompose the LbL film at low glucose concentrations of 1–10 mM.

Adsoption CD34 Antibody onto the Col/Hep Coating Film on Titanium to Improve Cytocompatibility of Titanium

2008 ◽  
Vol 47-50 ◽  
pp. 1411-1414 ◽  
Author(s):  
Jia Long Chen ◽  
Quan Li Li ◽  
Jun Ying Chen ◽  
Nan Huang
Keyword(s):  
Self Assembly ◽  
Electrostatic Interactions ◽  
Layer By Layer ◽  
Coating Film ◽  
Test Results ◽  
Cardiovascular Devices ◽  
Assembly Technique ◽  
Confluent Cell ◽  
Good Potential ◽  
Positively Charged

This study deals with improving the cytocompatibility of titanium by a coating with heparin(hep), collagen(col) and CD34 antibody. Collagen and heparin molecules were adsorbed onto a titanium surface using a layer-by-layer (LBL) self-assembly technique. The col/hep coating were formed by alternating deposition of negatively charged heparin and positively charged collagen based on electrostatic interactions. Finally the CD34 antibody was absorbed onto the surface of col/hep coating by electrostatic interactions. The chemical composition and surface topography were investigated by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The fluorescence microscopy images proved that the CD34 antibody was existed on the surface of the col/hep coating. The SEM results and the MTT test results showed that, compared to the surface of col/hep coating and the surface of titanium, the CD34 surface had better endothelial progenitor cells (EPCs) attachment and proliferation. The EPCs on the CD34 surface displayed the morphology of flat endothelium, and a confluent cell layer after cultured for 2d. This study suggested that this method maybe have good potential for surface modification of cardiovascular devices.

scholarly journals Modified Gold Nanoparticles to Overcome the Chemoresistance to Gemcitabine in Mutant p53 Cancer Cells

Pharmaceutics ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2067
Author(s):  
Eduardo García-Garrido ◽  
Marco Cordani ◽  
Álvaro Somoza
Keyword(s):  
Gold Nanoparticles ◽  
Cancer Cells ◽  
Electrostatic Interactions ◽  
Human Cancer ◽  
Tp53 Gene ◽  
Therapeutic Strategies ◽  
Mutant P53 ◽  
Layer By Layer ◽  
Missense Mutations ◽  
Efficient Delivery

Mutant p53 proteins result from missense mutations in the TP53 gene, the most mutated in human cancer, and have been described to contribute to cancer initiation and progression. Therapeutic strategies for targeting mutant p53 proteins in cancer cells are limited and have proved unsuitable for clinical application due to problems related to drug delivery and toxicity to healthy tissues. Therefore, the discovery of efficient and safe therapeutic strategies that specifically target mutant p53 remains challenging. In this study, we generated gold nanoparticles (AuNPs) chemically modified with low molecular branched polyethylenimine (bPEI) for the efficient delivery of gapmers targeting p53 mutant protein. The AuNPs formulation consists of a combination of polymeric mixed layer of polyethylene glycol (PEG) and PEI, and layer-by-layer assembly of bPEI through a sensitive linker. These nanoparticles can bind oligonucleotides through electrostatic interactions and release them in the presence of a reducing agent as glutathione. The nanostructures generated here provide a non-toxic and powerful system for the delivery of gapmers in cancer cells, which significantly downregulated mutant p53 proteins and altered molecular markers related to cell growth and apoptosis, thus overcoming chemoresistance to gemcitabine.

scholarly journals Egg White Protein-Hypophosphorous Acid Based Fire Retardant Single Bilayer Coating Assembly for Cotton Fabric

2021 ◽  
Author(s):  
Ajay Vishwakarma ◽  
Vennapusa Jagadeeswara Reddy ◽  
Baljinder K. Kandola ◽  
Aravind Dasari ◽  
Sujay Chattopadhyay
Keyword(s):  
Cotton Fabric ◽  
Electrostatic Interactions ◽  
Fire Retardant ◽  
Egg White ◽  
Layer By Layer ◽  
Initial Decomposition Temperature ◽  
Hypophosphorous Acid ◽  
Egg White Protein ◽  
Coated Fabric ◽  
Char Structure

Abstract Egg white proteins (W) in combination with hypophosphorous acid (HA) were investigated for making flame retardant coating over cotton fabric adopting layer by layer (LbL) assembly technique. A novel phosphorous-nitrogen based non-inflammatory pathway was produced due to strong electrostatic interactions between egg white protein and HA. The coated cotton fabric was characterized using FESEM, ATR-FTIR, TGA and flame tests. Vertical flame test (VFT) and BS EN ISO 15025 tests were performed to understand the combustion pattern of coated fabric. The cotton fabric coated with egg white protein followed by HA (CTW+HA) showed self-extinguish properties with fragile char structure, whereas uncoated fabric was completely burnt with ash residue. Thermogravimetric analysis revealed that initial decomposition temperature of coated fabric got lowered but raised the char residue at 800 ℃. Moreover, surface morphology after VFT of CTW+HA showed swollen char structure that prevented the interaction of combustible products with oxygen and heat. Thus, the developed coating could serve as excellent fire retardant due to the synergistic effect of HA and egg white protein.

scholarly journals Revisiting the Cytotoxicity of Cationic Polyelectrolytes as a Principal Component in Layer-by-Layer Assembly Fabrication

Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1230
Author(s):  
Ekaterina Naumenko ◽  
Farida Akhatova ◽  
Elvira Rozhina ◽  
Rawil Fakhrullin
Keyword(s):  
Gene Delivery ◽  
Electrostatic Interactions ◽  
Surface Engineering ◽  
Delivery Systems ◽  
In Vitro Cytotoxicity ◽  
Water Soluble ◽  
Layer By Layer ◽  
Dependent Manner ◽  
Cationic Polyelectrolytes

Polycations are an essential part of layer-by-layer (LbL)-assembled drug delivery systems, especially for gene delivery. In addition, they are used for other related applications, such as cell surface engineering. As a result, an assessment of the cytotoxicity of polycations and elucidation of the mechanisms of polycation toxicity is of paramount importance. In this study, we examined in detail the effects of a variety of water-soluble, positively charged synthetic polyelectrolytes on in vitro cytotoxicity, cell and nucleus morphology, and monolayer expansion changes. We have ranked the most popular cationic polyelectrolytes from the safest to the most toxic in relation to cell cultures. 3D cellular cluster formation was disturbed by addition of polyelectrolytes in most cases in a dose-dependent manner. Atomic force microscopy allowed us to visualize in detail the structures of the polyelectrolyte–DNA complexes formed due to electrostatic interactions. Our results indicate a relationship between the structure of the polyelectrolytes and their toxicity, which is necessary for optimization of drug and gene delivery systems.

scholarly journals Nanocoating for biomolecule delivery using layer-by-layer self-assembly

2015 ◽  
Vol 3 (45) ◽  
pp. 8757-8770 ◽  
Author(s):  
M. Keeney ◽  
X. Y. Jiang ◽  
M. Yamane ◽  
M. Lee ◽  
S. Goodman ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Self Assembly ◽  
Electrostatic Interactions ◽  
Layer By Layer ◽  
Biological Interactions

Schematic illustrates the formation of LbL coatings using different methods. (A) Electrostatic interactions; (B) Hydrogen bonding; or (C) Biological interactions.

scholarly journals Voltammetric pH Measurements Using Azure A-Containing Layer-by-Layer Film Immobilized Electrodes

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2328
Author(s):  
Kazuhiro Watanabe ◽  
Kyoko Sugiyama ◽  
Sachiko Komatsu ◽  
Kentaro Yoshida ◽  
Tetsuya Ono ◽  
...  
Keyword(s):  
Electrostatic Interactions ◽  
Measurement Techniques ◽  
Differential Pulse ◽  
Oxidation Potential ◽  
Repeated Measurements ◽  
Layer By Layer ◽  
Peak Potential ◽  
Azure A ◽  
Ph Range ◽  
Potential Shifts

pH is one of the most important properties associated with an aqueous solution and various pH measurement techniques are available. In this study, Azure A-modified poly(methacrylic acid) (AA-PMA) was synthesized used to prepare a layer-by-layer deposited film with poly(allylamine hydrochloride) (PAH) on a glassy carbon electrode via electrostatic interactions and the multilayer film-immobilized electrode was used to measure pH. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) measurement were performed. Consequently, the oxidation potential of AA on the electrode changed with pH. As per Nernst’s equation, because H+ ions are involved in the redox reaction, the peak potential shifted depending on the pH of the solution. The peak potential shifts are easier to detect by DPV than CV measurement. Accordingly, using electrochemical responses, the pH was successfully measured in the pH range of 3 to 9, and the electrodes were usable for 50 repeated measurements. Moreover, these electrochemical responses were not affected by interfering substances.

Decomposition of Glucose-Sensitive Layer-by-Layer Films Using Hemin, DNA, and Glucose Oxidase

2019 ◽  
Author(s):  
Kentaro Yoshida ◽  
Yu Kashimura ◽  
Toshio Kamijo ◽  
Tetsuya Ono ◽  
Takenori Dairaku ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Glucose Oxidase ◽  
Glucose Concentration ◽  
Dna Cleavage ◽  
Electrostatic Interactions ◽  
Glucose Solution ◽  
Layer By Layer ◽  
Sensitive Layer ◽  
Physiological Conditions ◽  
Lbl Films

Glucose-sensitive films were prepared by the layer-by-layer (LbL) deposition of poly(ethyleneimine) (H-PEI) solution and DNA solution (containing glucose oxidase (GOx)). H-PEI/DNA+GOx multilayer films were constructed using electrostatic interactions. The (H-PEI/DNA+GOx)5 film was then partially decomposed by hydrogen peroxide (H2O2). The mechanism for the decomposition of the LbL film was considered to involve a more reactive oxygen species (ROS) that was formed by the reaction of hemin and H2O2, which then caused nonspecific DNA cleavage. GOx present in the LbL films reacts with glucose to generate hydrogen peroxide. Therefore, decomposition of the H-PEI/DNA+GOx)5 film was observed when the thin film was immersed in a glucose solution. A (H-PEI/DNA+GOx)5 film exposed to a glucose solution for periods of 24, 48 72, and 96 h indicated decomposition of the film increased with the time. The rate of LbL film decomposition increased with the glucose concentration. At pH and ionic strength close to physiological conditions, it was possible to slowly decompose the LbL film at a sub-millimolar glucose concentration.

Sign in / Sign up

Export Citation Format

Share Document