<i>In Vitro</i> Assessment of the Hemocompatible Properties of Polymers

Sevastianov, V. I.; Belomestnaia, Zinaida M.; Zimin, N. K.

doi:10.1111/j.1525-1594.1983.tb04171.x

Cited by 17 publications

(6 citation statements)

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“…Local topography data obtained with AFM were complemented with X-ray reflectometry thickness measurements, which averaged over large areas. We believe that our observations are consistent with theoretical descriptions of the various simultaneously occurring processes of adsorption, conformational changes, and desorption of protein molecules, 26 which have appeared in the literature, [27][28][29] and we consider our experimental observations in light of those concepts. First we discuss the variation in adsorbed layer morphology with concentration.…”

Section: Discussionsupporting

confidence: 90%

Atomic Force Microscopy and X-ray Reflectivity Studies of Albumin Adsorbed onto Self-Assembled Monolayers of Hexadecyltrichlorosilane

et al. 1998

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Atomic force microscopy (AFM) and X-ray reflectivity (XR) have been used together to provide a detailed and direct look at the structure of human serum albumin protein adsorbed onto well-characterized selfassembled monolayer (SAM) surfaces at several protein concentrations. The duration of SAM deposition was also varied to investigate the influence of the density of hydrocarbon chains in the SAM on protein binding tenacity. Concurrent study of adsorption to bare silicon wafers with native oxide surfaces provided a comparison with a hydrophilic surface similar to widely studied glass and quartz surfaces. Both AFM and XR measurements showed that after adsorption, rinsing, and drying, the surfaces of all substrates were covered with no more than a single layer of adsorbed protein. Thin dense protein layers were seen for the substrates exposed to protein concentrations of 0.1 and 0.5 mg/mL. Partial surface coverage by protein aggregates having larger thicknesses was seen for substrates exposed to lower concentrations. The tenacity of the protein adsorption on different substrates was tested by eluting the adsorbed protein with a 1% solution of sodium dodecyl sulfate surfactant. This treatment removed almost all protein from the bare silicon surface and from the fully formed, dense SAMs. A significant amount of adsorbed protein remained on the surface of the less dense, "incomplete" monolayers, suggesting that protein adsorbed more tenaciously on that surface.

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Section: Discussionsupporting

confidence: 90%

Atomic Force Microscopy and X-ray Reflectivity Studies of Albumin Adsorbed onto Self-Assembled Monolayers of Hexadecyltrichlorosilane

et al. 1998

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“…Whole blood was obtained from at least three donors in tubes containing Li‐heparin as an anticoagulant and the supernatant was collected and used to determine plasma‐free hemoglobin as previously described (DeSilva et al, ; Malinauskas, ; Sevastianov et al, ). EVs were added, and 10 mg ml −1 poly‐ l ‐lysine and polyethylene glycol (40% stock solution) were used as positive and negative controls respectively.…”

Section: Methodsmentioning

confidence: 99%

In vitrotoxicology studies of extracellular vesicles

et al. 2016

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Extracellular vesicles (EVs) are membrane-bound vesicles released from cells into the extracellular environment. There is emerging interest in the use of EVs as potential therapeutic interventions. We sought to evaluate the safety of EVs that may be therapeutically used by performing in vitro toxicological assessments. EVs were obtained from mesenchymal stem cells (MSC-EV) or from bovine milk (BM-EV) by differential ultracentrifugation, and quantitated using nanoparticle tracking analysis. Genotoxic effects, hematological effects, immunological effects and endotoxin production were evaluated at two dose levels. Neither MSC-EVs nor BM-EVs elicited detectable genotoxic effects using either the alkaline comet assay or micronucleus assay. Hemolysis was observed with BM-EVs but not with MSC-EVs. MSC-EVs did not have any significant effect on either spontaneous or collagen-induced platelet aggregation. In contrast, BM-EVs were noted to increase collagen-induced platelet aggregation, even though no spontaneous increase in platelet aggregation was noted. Both types of EVs induced leukocyte proliferation, which was greater with BM-EV. Neither MSC-EVs nor BM-EVs induced HL-60 phagocytosis, although BM-EVs decreased zymosan-induced phagocytosis. Furthermore, neither MSC-EVs nor BM-EVs induced nitric oxide production. Unlike MSC-EVs, BM-EVs tested positive for endotoxin and induced complement activation. There are significant differences in toxicological profiles between MSC-EVs and BM-EVs that may reflect variations in techniques for EV isolation, EV content or cross-species differences. The safety of MSC-EV supports their use for disease therapeutics, whereas detailed safety and toxicological assessment will be necessary before the use of BM-EVs. Copyright © 2016 John Wiley & Sons, Ltd.

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“…Platelet adhesion was determined according to the following procedure [17,32]: brie y, whole blood of healthy adult donors was drawn by venipuncture into siliconized glass vials. 10 ml blood was anticoagulated 9 : 1 with sodium citrate.…”

Section: Investigation Of Hemocompatibility Of Phasmentioning

confidence: 99%

“…Low density polyethylene (LDPE) for medical use served as a control (N contr tot , N contr i ) sample. RIPA did not depend on biological variability of blood properties of different donors [32], which allowed using several donors with results being averaged afterwards. Student's t-test was applied to check the difference of average values whenever necessary.…”

Section: Investigation Of Hemocompatibility Of Phasmentioning

confidence: 99%

Production of purified polyhydroxyalkanoates (PHAs) for applications in contact with blood

Sevastianov¹,

Perova²,

Shishatskaya³

et al. 2003

Journal of Biomaterials Science, Polymer Edition

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Samples of olyhydroxyalkanoates (PHAs), polyhydroxybutyrate (PHB) and copolymers poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) with 4 and 18 mol% hydroxyvalerate, synthesized by the bacteria Ralstonia eutropha B5786, were investigated. PHA films in contact with blood did not activate the hemostasis system at the level of cell response, but they did activate the coagulation system and the complement reaction. To detect biologically-active components in the PHAs, a detailed analysis of the composition of the polymers was conducted. Gas chromatography-mass spectrometry revealed long-chain fatty acids (FAs) in the tested PHAs. Their total concentration in the polymer ranged from tenths of mol% to 2-3 mol%, depending on the purification method. C16:0 constituted the largest proportion, up to 70%. Of the long-chain hydroxy acids, only beta-OH-C14:0 was detected and it did not exceed 0.06 mol%. The analysis of the hemocompatibility properties of the PHAs purified by a specialized procedure, including the quantitative and morphological estimation of platelets adherent to the surface of polymer films, the plasma recalcification time and complement activation studies, indicated that PHB and PHBV can be used in contact with blood. It has been found out that the lipopolysaccharides of bacteria producing PHAs, which contain mostly long-chain hydroxy acids, can be the factor activating the hemostasis systems. Thus, the technology of PHA purification must satisfy rather stringent specific requirements.

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In Vitro Assessment of the Hemocompatible Properties of Polymers

Cited by 17 publications

References 0 publications

Atomic Force Microscopy and X-ray Reflectivity Studies of Albumin Adsorbed onto Self-Assembled Monolayers of Hexadecyltrichlorosilane

Atomic Force Microscopy and X-ray Reflectivity Studies of Albumin Adsorbed onto Self-Assembled Monolayers of Hexadecyltrichlorosilane

In vitrotoxicology studies of extracellular vesicles

Production of purified polyhydroxyalkanoates (PHAs) for applications in contact with blood

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