Blood Compatibility of Amphiphilic Phosphorous Dendrons—Prospective Drug Nanocarriers

Dendrons are branched synthetic polymers suitable for preparation of nanosized drug delivery systems. Their interactions with biological systems are mainly predetermined by their chemical structure, terminal groups, surface charge, and the number of branched layers (generation). Any new compound intended to be used, alone or in combination, for medical purposes in humans must be compatible with blood. This study combined results from in vitro experiments on human blood and from laboratory experiments designed to assess the effect of amphiphilic phosphorous dendrons on blood components and model membranes, and to examine the presence and nature of interactions leading to a potential safety concern. The changes in hematological and coagulation parameters upon the addition of dendrons in the concentration range of 2–10 µM were monitored. We found that only the combination of higher concentration and higher generation of the dendron affected the selected clinically relevant parameters: it significantly decreased platelet count and plateletcrit, shortened thrombin time, and increased activated partial thromboplastin time. At the same time, occasional small-sized platelet clumps in blood films under the light microscope were observed. We further investigated aggregation propensity of the positively charged dendrons in model conditions using zwitterionic and negatively charged liposomes. The observed changes in size and zeta potential indicated the electrostatic nature of the interaction. Overall, we proved that the low-generation amphiphilic phosphorous dendrons were compatible with blood within the studied concentration range. However, interactions between high-generation dendrons at bulk concentrations above 10 µM and platelets and/or clotting factors cannot be excluded.

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THE EFFECT OF THE VENOM OF THE ORIENTAL HORNET ON COAGULATION FACTORS

10.1055/s-0038-1644338 ◽

1987 ◽

Author(s):

A Kornberg ◽

S Kaufman ◽

L Silber ◽

J Ishay

Keyword(s):

Human Plasma ◽

Degradation Products ◽

Anticoagulant Activity ◽

Coagulation Factors ◽

Plasma Fibrinogen ◽

Thrombin Time ◽

Clotting Factors ◽

Viii And Ix

The extract from the venom sac of Vespa orientalis (VSE) inactivates exogenous and endogenous thromboplastin (Joshua and Ishay, Toxicon, 13:11-20,1975). The prolongation of both prothrombin time (PT) and recalcification time suggests inactivation of other factors. The aim of the present study is to investigate the effect of VSE on clotting factors. A lyophilized VSE with protein concentration of 5 mg/ml was used. Studies were performed in vitro with human plasma and in vivo in cats. Routine methods were employed for the assay of PT, activated tissue thromboplastin (APTT), thrombin time (TT), fibrinogen degradation products (FDP), fibrinogen and factors V,VII,VIII,IX,X. Human plasma was incubated with various concentrations of VSE (0,1,5,10,50,100 μg/ml) for 60 min and for various incubation times (0,5,15,30,+ 60,90,120 min) with 50 μg/ml VSE (n=8). 1 μg/ml VSE prolonged PT from 13.5 to 16 sec (p<0.05) and APTT from 62 to 180 sec. PT was maximal (17.7 sec) with 10 μg/ml and APTT (442 sec) with 50 μg/ml VSE. Factors V,VII,X decreased gradually from 94-105% to 11%,11% and 29% with 100 μg/ml VSE and VIII and IX to 1% even with 1 μg/ml VSE. After 5 min with constant concentration of VSE (50 μg/ml) PT was 14.9 sec (normal 13 sec) and APTT 165 sec (normal 54 sec). Both were maximal (17.5 and 298 sec) after 60 min. Factors VII and X decreased to 13% and 32% and VIII and IX to >1% after 60 min of incubation. Injection of 5 mg/kg VSE to cats (n=6-8) resulted in prolongation of PT from 9.4 to 11.2 sec and of APTT from 19.5 to 63 sec after 5 min. Both were maximal after 90 min (12.3 and 127 sec). Factors V,VII and X decreased from 100% to 7.6%, 13% and 37% and VIII and IX to 1% after 10 min. In all experiments TT and plasma fibrinogen were not affected and FDP were normal. Heating of VSE for 5 min at 80°C abolished completely the anticoagulant activity but dialysis for 24 hr at 4°C had no effect on it. The activity was eluted on Sephadex-25 both in void and post void volumes. The results show that VSE has a potent anticoagulant activity against various factors. Factors VIII and IX are markedly decreased. The effect on V, VII and X is moderate. Plasma fibrinogen is not affected. The nature and clinical significance of the anticoagulant activity merit further investigation.

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A Comparison of the Anticoagulant Actions of Commercially Available Contrast Media (CM)

10.1055/s-0039-1682755 ◽

1977 ◽

Author(s):

Rogelio Moneada ◽

Jawed Fareed ◽

Harry Messmore ◽

Terrence Demos

Keyword(s):

Sodium Chloride ◽

Contrast Media ◽

Toluidine Blue ◽

Partial Thromboplastin Time ◽

Antithrombin Iii ◽

Thrombin Time ◽

Clotting Factors ◽

Antithrombin Activity ◽

Viii And Ix

Previous studies have reported on the anticoagulant effect of commercially available contrast media used in diagnostic radiology. The purpose of this study is to compare the anticoagulant actions of these agents in vitro. Eight commercially available contrast medias were supplemented to citrated human plasma (CNP) in 1:10, 1:20 and 1:50 proportions; isomolar sucrose, glucose, sodium chloride, and saline supplemented CNP were used as controls. Prothrombin time (FT) , partial thromboplastin time (PTT), thrombin time (TT), antithrombin-III, plasminogenplasnun and factor assays were performed at 0 time, 30 minutes and 2 hours after incubation at 37°C. No significant alteration of the coagulation parameters were observed at 1:50 dilution, however at 1:10 and 1:20 dilution, most contrast media produced aberration of clotting parameters. The antithrombin potency of these contrast media at a 1:10 dilution ranged from 0.3-1.3 u/ml heparin. In addition, this antithrombin activity was synergistic with heparin. The antithrombin activity of these agents was not neutralized by protamine sulfate, polybrene or toluidine blue in the amounts which neutralized 1 u/ml heparin. Analysis of various clotting factors revealed that factors II, V, VII and XII were not affected by contrast media. Factors VIII and IX were depressed significantly. These changes were mainly dependent on the concentration of meglumine in the contrast media. Similar studies on the blood obtained from patients infused with contrast media for diagnostic purposes are in progress in our laboratory.

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Blood Compatibility of Stainless-Steel and Titanium Immobilized with Alginic Acid Layers

MRS Proceedings ◽

10.1557/proc-734-b9.48 ◽

2002 ◽

Vol 734 ◽

Cited By ~ 1

Author(s):

Tomohiko Yoshioka ◽

Kanji Tsuru ◽

Satoshi Hayakawa ◽

Akiyoshi Osaka

Keyword(s):

Stainless Steel ◽

Photoelectron Spectroscopy ◽

Blood Clotting ◽

Alginic Acid ◽

Blood Compatibility ◽

Adhesion Assay ◽

Clotting Factors ◽

Titanium Substrates ◽

Blood Clotting Factors

ABSTRACTγ-Aminopropyltriethoxysilane (γ-APS) was grafted on stainless-steel and titanium substrates, and subsequently alginic acid layer was immobilized on them. Their surfaces were characterized with X-ray photoelectron spectroscopy (XPS) and contact angle measurement. Blood compatibility of thus obtained substrates was evaluated in terms of both the number of the adhered platelets and blood clotting factors for plasma contacted with the substrates such as active partial thromboplastin time (PTT), prothrombin time (PT), and amount of fibrinogen (Fib). The steel and titanium substrates with alginic acid layer did not affect blood clotting factors. In vitro platelet adhesion assay indicated that those substrates adhered less number of platelets than non-treated substrates. Hence the alginic acid immobilization leads to blood compatible surfaces.

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Design of polymeric nanocapsules to improve their lympho-targeting capacity

Nanomedicine ◽

10.2217/nnm-2019-0206 ◽

2019 ◽

Vol 14 (23) ◽

pp. 3013-3033 ◽

Cited By ~ 2

Author(s):

José Crecente-Campo ◽

Tommaso Virgilio ◽

Diego Morone ◽

Cristina Calviño-Sampedro ◽

Iago Fernández-Mariño ◽

...

Keyword(s):

Dendritic Cells ◽

Lymph Node ◽

3D Reconstruction ◽

Immune Cells ◽

Lymphatic System ◽

Solvent Displacement ◽

Polymeric Nanocapsules ◽

Drug Nanocarriers ◽

Positively Charged

Aim: To design lympho-targeted nanocarriers with the capacity to enhance the activity of associated drugs/antigens whose target is within the lymphatic system. Materials & methods: Inulin (INU)-based nanocapsules (NCs), negatively charged and positively charged chitosan NCs were prepared by the solvent displacement techniques. The NCs were produced in two sizes: small (70 nm) and medium (170–250 nm). Results: In vitro results indicated that small NCs interacted more efficiently with dendritic cells than the larger ones. The study of the NCs biodistribution in mice, using 3D reconstruction of the popliteal lymph node, showed that small INU NCs have the greatest access and uniform accumulation in different subsets of resident immune cells. Conclusion: Small and negatively charged INU NCs have a potential as lympho-targeted antigen/drug nanocarriers.

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In Vitro Effects of Urokinase — Prevention by Different Inhibitors

Thrombosis and Haemostasis ◽

10.1055/s-0038-1647327 ◽

1990 ◽

Vol 64 (03) ◽

pp. 402-406 ◽

Cited By ~ 5

Author(s):

M D Oethinger ◽

E Seifried

Keyword(s):

In Vitro Study ◽

Thrombin Time ◽

Plasma Samples ◽

Temperature Dependent ◽

Chloromethyl Ketone ◽

Control Value ◽

Dose Time ◽

In Vitro Effects ◽

Full Protection

SummaryThe present in vitro study investigated dose-, time- and temperature-dependent effects of two-chain urokinase plasminogen activato(u-PA, urokinase) on normal citrated plasma. When 10 μg/ml u-PA wereadded to pooled normal plasma and incubated for 30 min at an ambient temperature (25° C), α2-antiplas-min decreased to 8% of the control value. Incubation on ice yielded a decrease to 45% of control,whereas α2-antiplasmin was fully consumed at 37° C. Fibrinogen and plasminogen fell to 46% and 39%, respectively, after a 30 min incubation at 25° C. Thrombin time prolonged to 190% of control.Various inhibitors were studied with respect to their suitability and efficacy to prevent these in vitro effects. Aprotinin exhibited a good protective effect on fibrinogen at concentrations exceeding 500 KlU/ml plasma. Its use, however, was limited due to interferences with some haemostatic assays. We could demonstrate that L-Glutamyl-L-Glycyl-L-Arginyl chloromethyl ketone (GGACK) and a specific polyclonal anti-u-PA-antibody (anti-u-PA-IgG) effectively inhibited urokinase-induced plasmin generation without interfering with haemostatic assays. The anti-u-PA-antibody afforded full protection ofα2-antiplasmin at therapeutic levels of u-PA.It is concluded that u-PA in plasma samples from patients during thrombolytic therapy may induce in vitro effects which should be prevented by the use of a suitable inhibitor such as GGACK or specific anti-u-PA-antibody.

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Effects of Heparin Oligosaccharides with High Affinity for Antithrombin III in Experimental Venous Thrombosis

Thrombosis and Haemostasis ◽

10.1055/s-0038-1657178 ◽

1982 ◽

Vol 47 (03) ◽

pp. 244-248 ◽

Cited By ~ 47

Author(s):

D P Thomas ◽

Rosemary E Merton ◽

T W Barrowcliffe ◽

L Thunberg ◽

U Lindahl

Keyword(s):

Antithrombin Iii ◽

Specific Activity ◽

High Specific Activity ◽

Factor Xa ◽

Blood Levels ◽

Thrombin Time ◽

High Affinity ◽

Very High

SummaryThe in vitro and in vivo characteristics of two oligosaccharide heparin fragments have been compared to those of unfractionated mucosal heparin. A decasaccharide fragment had essentially no activity by APTT or calcium thrombin time assays in vitro, but possessed very high specific activity by anti-Factor Xa assays. When injected into rabbits at doses of up to 80 ¼g/kg, this fragment was relatively ineffective in impairing stasis thrombosis despite producing high blood levels by anti-Xa assays. A 16-18 monosaccharide fragment had even higher specific activity (almost 2000 iu/mg) by chromogenic substrate anti-Xa assay, with minimal activity by APTT. When injected in vivo, this fragment gave low blood levels by APTT, very high anti-Xa levels, and was more effective in preventing thrombosis than the decasaccharide fragment. However, in comparison with unfractionated heparin, the 16-18 monosaccharide fragment was only partially effective in preventing thrombosis, despite producing much higher blood levels by anti-Xa assays.It is concluded that the high-affinity binding of a heparin fragment to antithrombin III does not by itself impair venous thrombogenesis, and that the anti-Factor Xa activity of heparin is only a partial expression of its therapeutic potential.

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Anticoagulant Properties of Three Mucopolysaccharides Used in Rheumatology

Thrombosis and Haemostasis ◽

10.1055/s-0038-1665279 ◽

1983 ◽

Vol 50 (03) ◽

pp. 652-655 ◽

Cited By ~ 1

Author(s):

F Bauer ◽

P Schulz ◽

G Reber ◽

C A Bouvier

Keyword(s):

Factor Xa ◽

Degenerative Joint Disease ◽

Joint Disease ◽

Thrombin Time ◽

Coagulation Tests ◽

Amplification System ◽

Relative Potencies ◽

In Vivo Administration

SummaryThree mucopolysaccharides (MPS) used in the treatment of degenerative joint disease were compared to heparin to establish their relative potencies on 3 coagulation tests, the aPTT, the antifactor X a activity and the dilute thrombin time. One of the compounds, Arteparon®, was one fourth as potent as heparin on the aPTT, but had little or no influence on the 2 other tests. Further in vitro studies suggested that Arteparon® acted at a higher level than factor Xa generation in the intrinsic amplification system and that its effect was independent of antithrombin III. In vivo administration of Arteparon® confirmed its anticoagulant properties, which raises the question of the clinical use of this MPS.

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Pan-American Lancehead Pit-Vipers: Coagulotoxic Venom Effects and Antivenom Neutralisation of Bothrops asper and B. atrox Geographical Variants

Toxins ◽

10.3390/toxins13020078 ◽

2021 ◽

Vol 13 (2) ◽

pp. 78

Author(s):

Lachlan A. Bourke ◽

Christina N. Zdenek ◽

Edgar Neri-Castro ◽

Melisa Bénard-Valle ◽

Alejandro Alagón ◽

...

Keyword(s):

Evolutionary Biology ◽

Current Knowledge ◽

Clinical Manifestations ◽

In Vivo Studies ◽

Factor X ◽

Clotting Factors ◽

Bothrops Asper ◽

Species Specific

The toxin composition of snake venoms and, thus, their functional activity, can vary between and within species. Intraspecific venom variation across a species’ geographic range is a major concern for antivenom treatment of envenomations, particularly for countries like French Guiana that lack a locally produced antivenom. Bothrops asper and Bothrops atrox are the most medically significant species of snakes in Latin America, both producing a variety of clinical manifestations, including systemic bleeding. These pathophysiological actions are due to the activation by the venom of the blood clotting factors Factor X and prothrombin, thereby causing severe consumptive coagulopathy. Both species are extremely wide-ranging, and previous studies have shown their venoms to exhibit regional venom variation. In this study, we investigate the differential coagulotoxic effects on human plasma of six venoms (four B. asper and two B. atrox samples) from different geographic locations, spanning from Mexico to Peru. We assessed how the venom variation of these venom samples affects neutralisation by five regionally available antivenoms: Antivipmyn, Antivipmyn-Tri, PoliVal-ICP, Bothrofav, and Soro Antibotrópico (SAB). The results revealed both inter- and intraspecific variations in the clotting activity of the venoms. These variations in turn resulted in significant variation in antivenom efficacy against the coagulotoxic effects of these venoms. Due to variations in the venoms used in the antivenom production process, antivenoms differed in their species-specific or geographical neutralisation capacity. Some antivenoms (PoliVal-ICP, Bothrofav, and SAB) showed species-specific patterns of neutralisation, while another antivenom (Antivipmyn) showed geographic-specific patterns of neutralisation. This study adds to current knowledge of Bothrops venoms and also illustrates the importance of considering evolutionary biology when developing antivenoms. Therefore, these results have tangible, real-world implications by aiding evidence-based design of antivenoms for treatment of the envenomed patient. We stress that these in vitro studies must be backed by future in vivo studies and clinical trials before therapeutic guidelines are issued regarding specific antivenom use in a clinical setting.

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Effects of Size and Surface Properties of Nanodiamonds on the Immunogenicity of Plant-Based H5 Protein of A/H5N1 Virus in Mice

Nanomaterials ◽

10.3390/nano11061597 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1597

Author(s):

Thuong Thi Ho ◽

Van Thi Pham ◽

Tra Thi Nguyen ◽

Vy Thai Trinh ◽

Tram Vi ◽

...

Keyword(s):

High Pressure ◽

Neutralizing Antibodies ◽

H5n1 Virus ◽

Vaccine Development ◽

Particle Characterization ◽

Innovative Strategy ◽

Specific Igg ◽

Positively Charged

Nanodiamond (ND) has recently emerged as a potential nanomaterial for nanovaccine development. Here, a plant-based haemagglutinin protein (H5.c2) of A/H5N1 virus was conjugated with detonation NDs (DND) of 3.7 nm in diameter (ND4), and high-pressure and high-temperature (HPHT) oxidative NDs of ~40–70 nm (ND40) and ~100–250 nm (ND100) in diameter. Our results revealed that the surface charge, but not the size of NDs, is crucial to the protein conjugation, as well as the in vitro and in vivo behaviors of H5.c2:ND conjugates. Positively charged ND4 does not effectively form stable conjugates with H5.c2, and has no impact on the immunogenicity of the protein both in vitro and in vivo. In contrast, the negatively oxidized NDs (ND40 and ND100) are excellent protein antigen carriers. When compared to free H5.c2, H5.c2:ND40, and H5.c2:ND100 conjugates are highly immunogenic with hemagglutination titers that are both 16 times higher than that of the free H5.c2 protein. Notably, H5.c2:ND40 and H5.c2:ND100 conjugates induce over 3-folds stronger production of both H5.c2-specific-IgG and neutralizing antibodies against A/H5N1 than free H5.c2 in mice. These findings support the innovative strategy of using negatively oxidized ND particles as novel antigen carriers for vaccine development, while also highlighting the importance of particle characterization before use.

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Calcium phosphate phase transition in the presence of Aminosilane

Acta Crystallographica Section A Foundations and Advances ◽

10.1107/s205327331409932x ◽

2014 ◽

Vol 70 (a1) ◽

pp. C67-C67

Author(s):

Babak Mostaghaci ◽

Brigitta Loretz ◽

Robert Haberkorn ◽

Guido Kickelbick ◽

Claus-Michael Lehr

Keyword(s):

Phase Transition ◽

Calcium Phosphate ◽

Blood Compatibility ◽

Transfection Efficiency ◽

Hek293 Cells ◽

Step Method ◽

Calcium Phosphate Nanoparticles ◽

Amine Groups ◽

The Impact

Calcium phosphate has been the point of interest for in vitro gene delivery for many years because of its biocompatibility and straight forward application. However, there are some limitations regarding in vivo administration of these particles mostly because of vast agglomeration of the particles and lack of strong bond between the particles and pDNA. We introduced a simple single step method to functionalize calcium phosphate nanoparticles with Aminosilanes having a different number of amine groups. The nanoparticles were characterized chemically and structurally and their toxicity and interaction with pDNA were studied as well. Results revealed that different crystalline phase of calcium phosphate nanoparticles (Brushite and Hydroxyapatite) with a size below 150 nm were prepared, depending on conditions of synthesis and phase, each with a narrow size distribution. The aminosilane agents caused oriented nucleation and growth of crystallites and can decrease the pH for producing hydroxyapatite phase. The phenomenon could be revealed with the presence of anisotropy in the structure of synthesized hydroxyapatite. The number of amine groups in the Aminosilane agent could change the phase transition pH. Brushite particles revealed to have stronger interaction with pDNA mostly because of their higher positive surface charge. Both particles showed blood compatibility and negligible toxicity. Transfection experiment revealed the capability of both brushite and hydroxyapatite particles to transfect A549 and HEK293 cells. The new modified nanoparticles can be stored in a dried state and re-dispersed easily at the time of administration. Moreover, the transfection efficiency is higher in comparison with conventional calcium phosphate. This study showed the impact of presence and type of the modifying agent on the crystal structure and the amount of surface functionalization of nanoparticles, which in consequence influenced their interaction with cells.

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