Plasma polymer surface modified expanded polytetrafluoroethylene promotes epithelial monolayer formation in vitro and can be transplanted into the dystrophic rat subretinal space

2020 ◽  
Author(s):  
Shen Nian ◽  
Victoria R. Kearns ◽  
David S. H. Wong ◽  
Akash Bachhuka ◽  
Krasimir Vasilev ◽  
...  
Keyword(s):  
Polymer Surface ◽  
Plasma Polymer ◽  
Subretinal Space ◽  
Epithelial Monolayer ◽  
Monolayer Formation ◽  
Expanded Polytetrafluoroethylene ◽  
Surface Modified

SPECTRAL CHARACTERIZATION OF REDOX-ACTIVE PRUSSIAN BLUE ON METALLATED PLASMA POLYMER SURFACE MODIFIED CARBON ELECTRODES USING PHOTOTHERMAL DETECTION

1983 ◽  
Vol 44 (C6) ◽  
pp. C6-285-C6-290 ◽  
Author(s):  
J. W. Childers ◽  
A. L. Crumbliss ◽  
P. S. Lugg ◽  
R. A. Palmer ◽  
N. Morosoff ◽  
...  
Keyword(s):  
Prussian Blue ◽  
Polymer Surface ◽  
Spectral Characterization ◽  
Plasma Polymer ◽  
Carbon Electrodes ◽  
Redox Active ◽  
Surface Modified

Binding of Tissue Plasminogen Activator to Vascular Grafts

1989 ◽  
Vol 61 (01) ◽  
pp. 131-136 ◽  
Author(s):  
Richard A Harvey ◽  
Hugh C Kim ◽  
Jonathan Pincus ◽  
Stanley Z Trooskin ◽  
Josiah N Wilcox ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Fibrinolytic Activity ◽  
Polymer Surface ◽  
Enzymic Activity ◽  
Vascular Prostheses ◽  
Chemically Modified ◽  
Insoluble Surfactant ◽  
Tissue Plasminogen

SummaryTissue plasminogen activator labeled with radioactive iodine (125I-tPA) was immobilized on vascular prostheses chemically modified with a thin coating of water-insoluble surfactant, tridodecylmethylammonium chloride (TDM AC). Surfactant- treated Dacron, polytetrafluoroethylene (PTFE), silastic, polyethylene and polyurethane bound appreciable amounts of 125I- tPA (5-30 μg 125I-tPA/cm2). Upon exposure to human plasma, the amount of 125I-tPA bound to the surface shows an initial drop during the first hour of incubation, followed by a slower, roughly exponential release with a t½ of appoximately 75 hours. Prostheses containing bound tPA show fibrinolytic activity as measured both by lysis of clots formed in vitro, and by hydrolysis of a synthetic polypeptide substrate. Prior to incubation in plasma, tPA bound to a polymer surface has an enzymic activity similar, if not identical to that of the native enzyme in buffered solution. However, exposure to plasma causes a decrease in the fibrinolytic activity of both bound tPA and enzyme released from the surface of the polymer. These data demonstrate that surfactant-treated prostheses can bind tPA, and that these chemically modified devices can act as a slow-release drug delivery system with the potential for reducing prosthesis-induced thromboembolism.

scholarly journals Bioactive Plasma Coatings on Orthodontic Brackets: In Vitro Metal Ion Release and Cytotoxicity

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 857
Author(s):  
Lasni Samalka Kumarasinghe ◽  
Neethu Ninan ◽  
Panthihage Ruvini Lakshika Dabare ◽  
Alex Cavallaro ◽  
Esma J. Doğramacı ◽  
...  
Keyword(s):  
Metal Ion ◽  
Prolonged Exposure ◽  
Orthodontic Brackets ◽  
Plasma Polymer ◽  
Functional Coatings ◽  
Key Factors ◽  
Ion Release ◽  
Metal Ion Release ◽  
Surface Functionalisation

The metal ion release characteristics and biocompatibility of meta-based materials are key factors that influence their use in orthodontics. Although stainless steel-based alloys have gained much interest and use due to their mechanical properties and cost, they are prone to localised attack after prolonged exposure to the hostile oral environment. Metal ions may induce cellular toxicity at high dosages. To circumvent these issues, orthodontic brackets were coated with a functional nano-thin layer of plasma polymer and further immobilised with enantiomers of tryptophan. Analysis of the physicochemical properties confirmed the presence of functional coatings on the surface of the brackets. The quantification of metal ion release using mass spectrometry proved that plasma functionalisation could minimise metal ion release from orthodontic brackets. Furthermore, the biocompatibility of the brackets has been improved after functionalisation. These findings demonstrate that plasma polymer facilitated surface functionalisation of orthodontic brackets is a promising approach to reducing metal toxicity without impacting their bulk properties.

In Vitro Mineralization and Cell Adhesion on Surface Modified Poly (2 - hydroxy ethyl methacrylate-co-methyl methacrylate

2006 ◽  
Vol 309-311 ◽  
pp. 493-496 ◽  
Author(s):  
G.S. Sailaja ◽  
T.V. Kumari ◽  
Yoshiyuki Yokogawa ◽  
H.K. Varma
Keyword(s):  
Cell Adhesion ◽  
Calcium Phosphate ◽  
Methyl Methacrylate ◽  
Radical Copolymerization ◽  
Sem Analysis ◽  
Free Radical Copolymerization ◽  
In Vitro Mineralization ◽  
Atr Spectroscopy ◽  
Surface Modified

Poly(2-hydroxyethyl methacrylate-co- methyl methacrylate) HM, was synthesized by free radical copolymerization, cross-linked with ethylene glycol dimethacrylate and phosphorylated. The phosphate coupling was ensured by ATR spectroscopy. The in vitro mineralization ability of the phosphorylated HM (designated as PHM) was investigated by studying the nucleation and growth of calcium phosphate on its surface by immersing in simulated body fluid (SBF) solution. The coating morphology was studied by SEM and the Ca/P ratio of the coating by EDX analysis. The cell adhesion behaviour of PHM was studied by seeding Human osteosarcoma (HOS) cells for one week followed by SEM analysis along with HM as control. It was observed that HOS cells exhibited biomineralization of calcium phosphate on the surface of HM as well as on PHM with a significantly higher amount on the surface of PHM as observed by von kossa staining method. The results show that PHM is capable of in vitro mineralization under simulated physiological condition, promotes cell adhesion by providing an excellent cell friendly surface and it exhibits biomineralization of calcium phosphate in presence of HOS cells.

Light-dependent hydration of the space surrounding photoreceptors in the cat retina

1994 ◽  
Vol 11 (4) ◽  
pp. 743-752 ◽  
Author(s):  
Jian-Dong Li ◽  
Victor I. Govardovskii ◽  
Roy H. Steinberg
Keyword(s):  
Mathematical Model ◽  
Time Course ◽  
Distal Portion ◽  
Subretinal Space ◽  
Volume Increase ◽  
Physiological Event ◽  
Cat Retina ◽  
Interphotoreceptor Matrix ◽  
Space Marker

AbstractWe have studied the effect of retinal illumination on the concentration of the extracellular space marker tetramethylammonium (TMA+) in the dark-adapted cat retina using double-barreled ion-selective microelectrodes. The retina was loaded with TMA+ by a single intravitreal injection. Retinal illumination produced a slow decrease in , which was maximal in amplitude in the most distal portion of the space surrounding photoreceptors, the subretinal space. The light-evoked decrease in was considerably slower and of a different overall time course than the light-evoked decrease in , also recorded in the subretinal space. decreased to a peak at 38 s after the onset of illumination, then slowly recovered towards the baseline, and transiently increased following the offset of illumination. It resembled the light-evoked decreases previously recorded in the in vitro preparations of frog (Huang & Karwoski, 1990, 1992) and chick (Li et al., 1992, 1994) but was considerably larger in amplitude, 22% compared with 7%. As in frog, where it was first recorded, the light-evoked decrease is considered to originate from a light-evoked increase in the volume of the subretinal space (or subretinal hydration). A mathematical model accounting for diffusion predicted that the volume increase underlying the response was 63% on average and could be as large as 95% and last for minutes. The estimated volume increase was then used to examine its effect on K+ concentration in the subretinal space. We conclude that a light-dependent hydration of the subretinal space represents a significant physiological event in the intact cat eye, which should affect the organization of the interphotoreceptor matrix, and the concentrations of all ions and metabolites located in the subretinal space.

scholarly journals Retraction: In vitro osteoinduction of human mesenchymal stem cells in biomimetic surface modified titanium alloy implants

2014 ◽  
Vol 33 (1) ◽  
pp. 148-148
Author(s):  
Sonia SANTANDER ◽  
Clara ALCAINE ◽  
Jaber LYAHYAI ◽  
Maria Angeles PÉREZ ◽  
Clementina RODELLAR ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Titanium Alloy ◽  
Human Mesenchymal Stem Cells ◽  
Biomimetic Surface ◽  
Surface Modified

Surface Modification Of Polymers With Grafting And Coating Of Silane Hybrids And Their Bioactivity

1999 ◽  
Vol 576 ◽  
Author(s):  
Masaaki Kubo ◽  
Seisuke Takashima ◽  
Kanji Tsuru ◽  
Satoshi Hayakawa ◽  
Akiyoshi Osaka ◽  
...  
Keyword(s):  
Contact Angle ◽  
High Density Polyethylene ◽  
Body Fluid ◽  
Chemical Species ◽  
Hydrated Silica ◽  
Bioactive Materials ◽  
Poly Vinyl Chloride ◽  
Essential Chemical ◽  
Surface Modified

ABSTRACTHydrated silica rich Si-OH and Si-0- groups serve in a body environment as sites for nucleation of apatite, and are known as an essential chemical species for bioactive materials. Organic polymers having surface modified with the hydrated silica will show bioactivity: bone tissues grow toward the apatite layer and bond to materials. Thus MOPS-M (3-methacryloxypropyltrimethoxysilane) was grafted under emulsion polymerization procedure to high density polyethylene (HDPE), poly (vinyl chloride) (PVC) and polyamide (PA) substrates to examine in vitro deposition of apatite (bioactivity) after soaking in a simulated body fluid (Kokubo solution). Bioactivity was confirmed for the grafted PVC and PA substrates and discussed in terms of contact angle and relative amount of grafted silane molecules.

scholarly journals Inhibition of Matriptase Activity Results in Decreased Intestinal Epithelial Monolayer Integrity In Vitro

PLoS ONE ◽  
2015 ◽  
Vol 10 (10) ◽  
pp. e0141077 ◽  
Author(s):  
E. Pászti-Gere ◽  
S. McManus ◽  
N. Meggyesházi ◽  
P. Balla ◽  
P. Gálfi ◽  
...  
Keyword(s):  
Intestinal Epithelial ◽  
Epithelial Monolayer

scholarly journals Modified Nanodiamonds as a Means of Polymer Surface Functionalization. From Fouling Suppression to Biosensor Design

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2980
Author(s):  
Pavel V. Melnikov ◽  
Anastasia Yu. Alexandrovskaya ◽  
Alina O. Naumova ◽  
Nadezhda M. Popova ◽  
Boris V. Spitsyn ◽  
...  
Keyword(s):  
Optical Sensors ◽  
Polymer Surface ◽  
Mixed Composition ◽  
Precise Control ◽  
Polar Groups ◽  
Bactericidal Properties ◽  
Wall Interaction ◽  
Biosensor Response

The development of different methods for tuning surface properties is currently of great interest. The presented work is devoted to the use of modified nanodiamonds to control the wetting and biological fouling of polymers using optical sensors as an example. We have shown that, depending on the type of modification and the amount of nanodiamonds, the surface of the same fluorinated polymer can have both bactericidal properties and, on the contrary, good adhesion to the biomaterial. The precise control of wetting and biofouling properties of the surface was achieved by the optimization of the modified nanodiamonds thermal anchoring conditions. In vitro and in vivo tests have shown that the fixation of amine functional groups leads to inhibition of biological activity, while the presence of a large number of polar groups of mixed composition (amide and acid chloride) promotes adhesion of the biomaterial and allows one to create a biosensor on-site. A comprehensive study made it possible to establish that in the first 5 days the observed biosensor response is provided by cells adhered to the surface due to the cell wall interaction. On the 7th day, the cells are fixed by means of the polysaccharide matrix, which provides much better retention on the surface and a noticeably greater response to substrate injections. Nevertheless, it is important to note that even 1.5 h of incubation is sufficient for the formation of the reliable bioreceptor on the surface with the modified nanodiamonds. The approach demonstrated in this work makes it possible to easily and quickly isolate the microbiome on the surface of the sensor and perform the necessary studies of its substrate specificity or resistance to toxic effects.

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