AFM and Fractal Analysis of Biomaterial Microtopography

1998 ◽  
Vol 4 (S2) ◽  
pp. 926-927
Author(s):  
S. Jo ◽  
T. Li ◽  
K. Park
Keyword(s):  
Surface Modification ◽  
Self Assembly ◽  
Blood Compatibility ◽  
Carbon Chain ◽  
Atomic Force ◽  
Covalent Grafting ◽  
Biomaterial Surfaces ◽  
Poly Ethylene ◽  
Glass Surfaces

Although significant advances have been made in the development of biocompatible materials, currently available biomaterials still present a number of problems for in vivo applications. One of the attempts to improve the biocompatibility, especially blood-compatibility, of biomaterials has been surface modification. Typically, poly(ethylene glycol) (PEG), albumin, heparin, and phospholipid molecules are grafted to the surface to prevent protein adsorption and cell adhesion. We have been modifying biomaterial surfaces by covalent grafting of PEG and albumin. The control and modified surfaces were examined using an atomic force microscope (AFM). In this study, we examined the surface topography changes by surface modification using PEO grafting to glass as a model system.Glass surfaces were modified with PEO using (N-triethoxysilylpropyl)-Omonomethoxy PEG urethane (PEG-Si), a PEG derivative containing a hydrophobic carbon chain and triethoxysilyl group at one end of the PEG chain. The presence of the hydrophobic carbon chain allowed self-assembly on the surface and triethoxysilyl resulted in covalent bonding to glass surfaces

Surface Modification of Copolyether-Urethane Catheters with Poly(Ethylene Oxide)

1989 ◽  
Vol 12 (6) ◽  
pp. 390-394 ◽  
Author(s):  
E. Brinkman ◽  
A. Poot ◽  
T. Beugeling ◽  
L. Van Der Does ◽  
A. Bantjes
Keyword(s):  
Surface Modification ◽  
Ethylene Oxide ◽  
Blood Compatibility ◽  
Angle Measurements ◽  
Fold Reduction ◽  
Contact Angle Measurements ◽  
Platelet Deposition ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

Pellethane 2363 80A catheters were modified with poly(ethylene oxide) in order to improve their blood compatibility. Contact angle measurements showed that Pellethane 2363 80A surfaces had increased wettability after this modification. The results of in vitro blood compatibility tests showed that surface modification with poly(ethylene oxide) resulted in a five-fold reduction of platelet deposition. Activation of coagulation was not affected.

Self-Assembled N-Succinyl-Chitosan Nanofibers for Reduced Protein Adhesion

2010 ◽  
Vol 76 ◽  
pp. 36-41
Author(s):  
Eyas Dayyoub ◽  
Udo Bakowsky
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Self Assembly ◽  
Adhesion Properties ◽  
Force Microscopy ◽  
Atomic Force ◽  
Biomaterial Surfaces ◽  
Force Curves ◽  
Protein Adhesion

Protein adhesion on biomaterial surfaces plays a major role in determining their biocompatibility and cell responses. The goal of this study was to produce chitosan-based coatings of implant material polyurethane (PUR) for reduced human serum albumin (HSA) adhesion. Succinic anhydride was employed for modifying chitosan and synthesis of N-succinyl-chitosan (NSCS) which was used as a matrix coating of PUR. NSCS showed self-assembly behaviour as nanofiber structures onto PUR surface. Atomic force microscopy (AFM) has emerged as useful tool for the molecular force measurements and therefore it has been chosen to investigate the adhesion properties of Human serum albumin (HSA) on the new matrix coatings and other three implant materials PUR, Silicon and Titanium. HSA molecules were covalently bound to the AFM tip by the use of cyanuric chloride as bivalent linker. Analyzing the force curves demonstrated the antiadhesive properties of the NSCS films in comparison with the uncoated PUR, Silicon and Titanium.

scholarly journals Nanosized Particles Assembled by a Recombinant Virus Protein Are Able to Encapsulate Negatively Charged Molecules and Structured RNA

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 858
Author(s):  
Hemalatha Mani ◽  
Yi-Cheng Chen ◽  
Yen-Kai Chen ◽  
Wei-Lin Liu ◽  
Shih-Yen Lo ◽  
...  
Keyword(s):  
Self Assembly ◽  
Rna Binding ◽  
Core Protein ◽  
Average Diameter ◽  
Virus Protein ◽  
Force Microscopy ◽  
Atomic Force ◽  
Hcv Core Protein

RNA-based molecules have recently become hot candidates to be developed into therapeutic agents. However, successful applications of RNA-based therapeutics might require suitable carriers to protect the RNA from enzymatic degradation by ubiquitous RNases in vivo. Because of their better biocompatibility and biodegradability, protein-based nanoparticles are considered to be alternatives to their synthetic polymer-based counterparts for drug delivery. Hepatitis C virus (HCV) core protein has been suggested to be able to self-assemble into nucleocapsid-like particles in vitro. In this study, the genomic RNA-binding domain of HCV core protein consisting of 116 amino acids (p116) was overexpressed with E. coli for investigation. The recombinant p116 was able to assemble into particles with an average diameter of approximately 27 nm, as visualized by electron microscopy and atomic force microscopy. Measurements with fluorescence spectroscopy, flow cytometry, and fluorescence quenching indicated that the p116-assembled nanoparticles were able to encapsulate small anionic molecules and structured RNA. This study demonstrates methods that exploit the self-assembly nature of a virus-derived protein for nanoparticle production. This study also suggests that the virus-derived protein-assembled particles could possibly be developed into potential carriers for anionic molecular drugs and structured RNA-based therapeutics.

Atomic Force Microscopy and Light Scattering Study of Onion-Type Micelles Formed by Polystyrene-block-poly(2-vinylpyridine) and Poly(2-vinylpyridine)-block-poly(ethylene oxide) Copolymers in Aqueous Solutions

2006 ◽  
Vol 71 (5) ◽  
pp. 723-738 ◽  
Author(s):  
Pavel Matějíček ◽  
Miroslav Štěpánek ◽  
Mariusz Uchman ◽  
Karel Procházka ◽  
Milena Špírková
Keyword(s):  
Atomic Force Microscopy ◽  
Light Scattering ◽  
Ethylene Oxide ◽  
Self Assembly ◽  
Distribution Functions ◽  
Force Microscopy ◽  
Mass Distributions ◽  
Atomic Force ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

The three-layer onion micelles formed in aqueous solution by hierarchical self-assembly of polystyrene-block-poly(2-vinylpyridine) micelles, PS-PVP, and poly(2-vinylpyridine)-block-poly(ethylene oxide) chains, PVP-PEO, were studied by a combination of light scattering (LS) and atomic force microscopy (AFM). Section analysis of AFM images of micelles deposited on mica in combination with LS data from micellar solutions provide distribution functions of sizes from which the number and mass distributions of molar masses of micelles can be evaluated. Both light scattering and AFM data reveal that the used preparation protocol yields onion micelles accompanied by an admixture of PVP-PEO micelles. It means that only a certain amount of PVP-PEO self-assembles with PS-PVP and forms onion micelles. The remaining PVP-PEO copolymer forms either small PVP-PEO micelles or participates in formation of large aggregates at longer times. The time-dependent measurements show that both onion-type and core-shell PVP-PEO micelles are fairly stable over a long time period and only a low fraction of large aggregate forms on the timescale of weeks and at longer times, the solution does not change any more.

scholarly journals Surface Modification by Nano-Structures Reduces Viable Bacterial Biofilm in Aerobic and Anaerobic Environments

2020 ◽  
Vol 21 (19) ◽  
pp. 7370
Author(s):  
Sarah Ya’ari ◽  
Michal Halperin-Sternfeld ◽  
Boris Rosin ◽  
Lihi Adler-Abramovich
Keyword(s):  
Surface Modification ◽  
Self Assembly ◽  
Antimicrobial Property ◽  
Bacterial Biofilm ◽  
Nano Structure ◽  
Self Assembling ◽  
Nano Structures ◽  
Coated Surfaces ◽  
Glass Surfaces ◽  
Aerobic And Anaerobic

Bacterial biofilm formation on wet surfaces represents a significant problem in medicine and environmental sciences. One of the strategies to prevent or eliminate surface adhesion of organisms is surface modification and coating. However, the current coating technologies possess several drawbacks, including limited durability, low biocompatibility and high cost. Here, we present a simple antibacterial modification of titanium, mica and glass surfaces using self-assembling nano-structures. We have designed two different nano-structure coatings composed of fluorinated phenylalanine via the drop-cast coating technique. We investigated and characterized the modified surfaces by scanning electron microscopy, X-ray diffraction and wettability analyses. Exploiting the antimicrobial property of the nano-structures, we successfully hindered the viability of Streptococcus mutans and Enterococcus faecalis on the coated surfaces in both aerobic and anaerobic conditions. Notably, we found lower bacteria adherence to the coated surfaces and a reduction of 86–99% in the total metabolic activity of the bacteria. Our results emphasize the interplay between self-assembly and antimicrobial activity of small self-assembling molecules, thus highlighting a new approach of biofilm control for implementation in biomedicine and other fields.

In vitro and In vivo Blood Compatibility of Concentrated Polymer Brushes

2021 ◽  
Author(s):  
Chiaki Yoshikawa ◽  
Shinya Hattori ◽  
Chih-Feng Huang ◽  
Hisatoshi Kobayashi ◽  
Masaru Tanaka
Keyword(s):  
Ethylene Glycol ◽  
Methyl Ether ◽  
Polymer Brushes ◽  
Blood Compatibility ◽  
Hydroxyethyl Methacrylate ◽  
Poly Ethylene Glycol ◽  
Poly Ethylene ◽  
Glycol Methyl Ether

Concentrated polymer brushes (CPBs) and semi-dilute polymer brushes (SDPBs) of poly(2-hydroxyethyl methacrylate), poly(2-hydroxyethyl acrylate), poly[poly(ethylene glycol) methyl ether methacrylate)] (PPEGMA) and poly(2-methoxyetyl acrylate) were prepared on silica particles and silicon...

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