scholarly journals Nanodroplet-mediated catheter-directed sonothrombolysis of retracted blood clots

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Leela Goel ◽  
Huaiyu Wu ◽  
Bohua Zhang ◽  
Jinwook Kim ◽  
Paul A. Dayton ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Negative Pressure ◽  
Boiling Point ◽  
Clot Lysis ◽  
Control Group ◽  
Peak Negative Pressure ◽  
Blood Clots ◽  
Tissue Plasminogen ◽  
First Time

AbstractOne major challenge in current microbubble (MB) and tissue plasminogen activator (tPA)-mediated sonothrombolysis techniques is effectively treating retracted blood clots, owing to the high density and low porosity of retracted clots. Nanodroplets (NDs) have the potential to enhance retracted clot lysis owing to their small size and ability to penetrate into retracted clots to enhance drug delivery. For the first time, we demonstrate that a sub-megahertz, forward-viewing intravascular (FVI) transducer can be used for ND-mediated sonothrombolysis, in vitro. In this study, we determined the minimum peak negative pressure to induce cavitation with low-boiling point phase change nanodroplets and clot lysis. We then compared nanodroplet mediated sonothrombolysis to MB and tPA mediate techniques. The clot lysis as a percent mass decrease in retracted clots was 9 ± 8%, 9 ± 5%, 16 ± 5%, 14 ± 9%, 17 ± 9%, 30 ± 8%, and 40 ± 9% for the control group, tPA alone, tPA + US, MB + US, MB + tPA + US, ND + US, and ND + tPA + US groups, respectively. In retracted blood clots, combined ND- and tPA-mediated sonothrombolysis was able to significantly enhance retracted clot lysis compared with traditional MB and tPA-mediated sonothrombolysis techniques. Combined nanodroplet with tPA-mediated sonothrombolysis may provide a feasible strategy for safely treating retracted clots.

scholarly journals In-vitro sonothrombolysis using thick-shelled polymer microbubbles - a comparison with thin-shelled microbubbles

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Jovana Janjic ◽  
Malin K Larsson ◽  
Anna Bjällmark
Keyword(s):  
Drug Delivery ◽  
Mass Loss ◽  
Low Pressure ◽  
Clot Lysis ◽  
Ultrasound Exposure ◽  
Blood Clots ◽  
Upstream Pressure ◽  
Set Up ◽  
Partially Occluded

Abstract Background Vascular thrombosis can be treated pharmacologically, however, serious shortcomings such as bleeding may occur. Several studies suggest that sonothrombolysis can induce lysis of the clots using ultrasound. Moreover, intravenously injected thin-shelled microbubbles (MBs) combined with ultrasound can further improve clot lysis. Thick-shelled MBs have been used for drug delivery, targeting and multimodal imaging. However, their capability to enhance sonothrombolysis is unknown. In this study, using an in-vitro set-up, the enhancement of clot lysis using ultrasound and thick-shelled MBs was investigated. Thin-shelled MBs was used for comparison. Method The main components in the in-vitro set-up was a vessel mimicking phantom, a pressure mearing system and programmable ultrasound machine. Blood clots were injected and entrapped on a pore mesh in the vessel phantom. Four different protocols for ultrasound transmission and MB exposure (7 blood clots/protocol) were considered together with a control test were no MBs and ultrasound were used. For each protocol, ultrasound exposure of 20 min was used. The upstream pressure of the partially occluded mesh was continuously measured to assess clot burden. At the end of each protocol blood clots were removed from the phantom and the clot mass loss was computed. Results For the thick-shelled MBs no difference in clot mass loss compared with the control tests was found. A 10% increase in the clot mass loss compared with the control tests was found when using thin-shelled MBs and low pressure/long pulses ultrasound exposure. Similarly, in terms of upstream pressure over exposure time, no differences were found when using the thick-shelled MBs, whereas thin-shelled MBs showed a 15% decrease achieved within the first 4 min of ultrasound exposure. Conclusion No increase in clot lysis was achieved using thick-shelled MBs as demonstrated by no significant change in clot mass or upstream pressure. Although thick-shelled MBs are promising for targeting and drug delivery, they do not enhance clot lysis when considering the ultrasound sequences used in this study. On the other hand, ultrasound in combination with thin-shelled MBs can facilitate thrombolysis when applying long ultrasound pulses with low pressure.

In Vitro Clot Lysis as a Potential Indicator of Thrombus Resistance to Fibrinolysis – Study in Healthy Subjects and Correlation with Blood Fibrinolytic Parameters

1997 ◽  
Vol 77 (04) ◽  
pp. 725-729 ◽  
Author(s):  
Mario Colucci ◽  
Silvia Scopece ◽  
Antonio V Gelato ◽  
Donato Dimonte ◽  
Nicola Semeraro
Keyword(s):  
Plasminogen Activator ◽  
Clot Lysis ◽  
Individual Response ◽  
Plasminogen Activator Inhibitor 1 ◽  
Autologous Plasma ◽  
Wide Range ◽  
Blood Clots ◽  
Physiological Variations ◽  
Pai 1

SummaryUsing an in vitro model of clot lysis, the individual response to a pharmacological concentration of recombinant tissue plasminogen activator (rt-PA) and the influence on this response of the physiological variations of blood parameters known to interfere with the fibrinolytic/thrombolytic process were investigated in 103 healthy donors. 125I-fibrin labelled blood clots were submersed in autologous plasma, supplemented with 500 ng/ml of rt-PA or solvent, and the degree of lysis was determined after 3 h of incubation at 37° C. Baseline plasma levels of t-PA, plasminogen activator inhibitor 1 (PAI-1), plasminogen, α2-anti-plasmin, fibrinogen, lipoprotein (a), thrombomodulin and von Willebrand factor as well as platelet and leukocyte count and clot retraction were also determined in each donor. rt-PA-induced clot lysis varied over a wide range (28-75%) and was significantly related to endogenous t-PA, PAI-1, plasminogen (p <0.001) and age (p <0.01). Multivariate analysis indicated that both PAI-1 antigen and plasminogen independently predicted low response to rt-PA. Surprisingly, however, not only PAI-1 but also plasminogen was negatively correlated with rt-PA-ginduced clot lysis. The observation that neutralization of PAI-1 by specific antibodies, both in plasma and within the clot, did not potentiate clot lysis indicates that the inhibitor, including the platelet-derived form, is insufficient to attenuate the thrombolytic activity of a pharmacological concentration of rt-PA and that its elevation, similarly to the elevation of plasminogen, is not the cause of clot resistance but rather a coincident finding. It is concluded that the in vitro response of blood clots to rt-PA is poorly influenced by the physiological variations of the examined parameters and that factors other than those evaluated in this study interfere with clot dissolution by rt-PA. In vitro clot lysis test might help to identify patients who may be resistant to thrombolytic therapy.

scholarly journals The mechanism of in vitro clot lysis induced by vascular plasminogen activator

Blood ◽  
1984 ◽  
Vol 63 (6) ◽  
pp. 1331-1337 ◽  
Author(s):  
C Tran-Thang ◽  
EK Kruithof ◽  
F Bachmann
Keyword(s):  
Plasminogen Activator ◽  
Whole Blood ◽  
Apparent Molecular Weight ◽  
Clot Lysis ◽  
Initial Concentration ◽  
Low Concentrations ◽  
Sds Page ◽  
Tissue Plasminogen ◽  
Low Rate

Abstract The contribution of vascular plasminogen activator (v-PA) to the lysis of whole blood and plasma clots was investigated. v-PA released into the circulation after infusion of deamino-D-arginine vasopressin (DDAVP) was shown to bind quantitatively to plasma clots. Its apparent molecular weight, determined by the SDS-PAGE fibrin-agarose underlay method, was approximately 68,000 daltons, and its activity was quenched by antibodies against human tissue plasminogen activator (t-PA). Clots prepared from post-DDAVP plasma or post-DDAVP whole blood, rich in v- PA, did not lyse when incubated in imidazole buffer or normal plasma, as determined by the release of 125I from radiolabeled clots. However, clots made of v-PA-poor plasma or whole blood, incubated in v-PA-rich plasma, underwent substantial lysis. The concentration of PA in clots incubated in v-PA-rich plasma progressively increased in relation to the initial concentration of v-PA in the surrounding plasma. The results suggest that, at low concentrations of circulating v-PA, a hemostatic plug will lyse at a very low rate. However, when the v-PA concentration in the clot environment is increased, v-PA will accumulate progressively onto fibrin and induce thrombolysis.

scholarly journals TITANIUM NANOPARTICLES CONJUGATED WITH STREPTOKINASE AS A MODIFIED THROMBOLYTIC AGENT

2020 ◽  
pp. 18-25
Author(s):  
HAYDER H. ABED ◽  
ESTABRAQ AR. ALWASITI ◽  
AMIR T. TAWFEEQ
Keyword(s):  
Thrombolytic Agent ◽  
Blood Clot ◽  
Control Group ◽  
Thrombolytic Activity ◽  
Protein Assay ◽  
Blood Clots ◽  
Ft Ir ◽  
Titanium Nanoparticles ◽  
D Dimer

Objective: Blood clots are the main cause of death worldwide by stroke and myocardial infarction. Streptokinase a thrombolytic agent that is used in the treatment of circulatory disorders. Methods: Titanium Nanoparticles was supplied from Changsha Santech Co. Its characterized were studied using (FT-IR, XRD, AFM, FE-SEM). Streptokinase at concentration 0.1 mg/ml was conjugated with Titanium nanoparticles using PH equal to 5.2 with continuous stirring. Formation of Streptokinase loading Titanium nanoparticles confirmed using FT-IR, Ninhydrine’s test and Bradford protein assay. Physicochemical Properties were studied in vitro. Thrombolytic activity in vitro was determined using d–dimer indicator and weight of blood clot after treatment as indicators of thrombolytic activity. Results: Titanium nanoparticles show particle size at range 31 nm. The thrombolytic activity of streptokinase loading Titanium nanoparticles shows significant value in d-dimer and weight of blood clot compared with the control group and non-significant compared with an equivalent amount of streptokinase alone. Conclusion: Titanium nanoparticles conjugated with streptokinase show high thrombolytic activity against blood clots in vitro.

Changes in Platelet Function, Blood Coagulation and Fibrinolysis During Insulin-Induced Hypoglycaemia in Juvenile Diabetics and Normal Subjects

1982 ◽  
Vol 47 (03) ◽  
pp. 254-258 ◽  
Author(s):  
J Dalsgaard-Nielsen ◽  
S Madsbad ◽  
J Hilsted
Keyword(s):  
Insulin Infusion ◽  
Adenosine Diphosphate ◽  
Normal Subjects ◽  
Clot Lysis ◽  
Control Group ◽  
Lysis Time ◽  
Euglobulin Clot Lysis Time ◽  
Juvenile Diabetics ◽  
Clot Lysis Time

SummaryHaemostatic parameters were assessed before insulin induced hypoglycaemia and 0, 1 and 2 fu after discontinuation of insulin infusion in 7 non-diabetics, aged 28 (22-31) years (mean and range), and 8 juvenile diabetics, aged 3L (27-35) years, with a mean duration of diabetes of 4 years. The patients were normoglycaemic for at least L0 hr before the study.Platelet aggregation in vitro was induced by lower adenosine diphosphate (ADP) concentrations in the diabetics than in the controls before hypoglycaemia and 0 and 60 min after insulin infusion. Platelet counts decreased significantly in the diabetics after hypoglycaemia, whereas no changes were seen in the control group. The activated partial thromboplastin time (APTT) was reduced in both groups and significantly lower in the diabetics than in the controls 120 min after insulin infusion.Fibrinogen and factor VIII R: Ag increased after insulin infusion; highest values were seen in the diabetics. The euglobulin clot lysis time (ELT) was reduced in both groups during insulin infusion; L20 min after end of insulin infusion ELT was significantly longer in the diabetics than in the control group.

scholarly journals Insightful Valorization of the Biological Activities of Pani Heloch Leaves through Experimental and Computer-Aided Mechanisms

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5153
Author(s):  
Naureen Banu ◽  
Najmul Alam ◽  
Mohammad Nazmul Islam ◽  
Sanjida Islam ◽  
Shahenur Alam Sakib ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Methanol Extract ◽  
Biological Activities ◽  
Biological Effects ◽  
Experimental Models ◽  
Clot Lysis ◽  
Control Group ◽  
Anti Inflammatory

Pani heloch (Antidesma montanum) is traditionally used to treat innumerable diseases and is a source of wild vegetables for the management of different pathological conditions. The present study explored the qualitative phytochemicals; quantitative phenol and flavonoid contents; in vitro antioxidant, anti-inflammatory, and thrombolytic effects; and in vivo antipyretic and analgesic properties of the methanol extract of A. montanum leaves in different experimental models. The extract exhibited secondary metabolites including alkaloids, flavonoids, flavanols, phytosterols, cholesterols, phenols, terpenoids, glycosides, fixed oils, emodines, coumarins, resins, and tannins. Besides, Pani heloch showed strong antioxidant activity (IC50 = 99.00 µg/mL), while a moderate percentage of clot lysis (31.56%) in human blood and significant anti-inflammatory activity (p < 0.001) was achieved with the standard. Moreover, the analgesic and antipyretic properties appeared to trigger a significant response (p < 0.001) relative to in the control group. Besides, an in silico study of carpusin revealed favorable protein-binding affinities. Furthermore, the absorption, distribution, metabolism, excretion, and toxicity analysis and toxicological properties of all isolated compounds adopted Lipinski’s rule of five for drug-like potential and level of toxicity. Our research unveiled that the methanol extract of A. montanum leaves exhibited secondary metabolites that are a good source for managing inflammation, pyrexia, pain, and cellular toxicity. Computational approaches and further studies are required to identify the possible mechanism which responsible for the biological effects.

Functional Fibrinolysis Assays Reveal Different Mechanisms underlying Plasminogen Dysfunction in Ligneous Conjunctivitis

2020 ◽  
Vol 120 (05) ◽  
pp. 758-767
Author(s):  
Marie-Charlotte Bourrienne ◽  
Stéphane Loyau ◽  
Dorothée Faille ◽  
Emmanuelle de Raucourt ◽  
Philippe de Mazancourt ◽  
...  
Keyword(s):  
Fibrinolytic Activity ◽  
Clot Lysis ◽  
Control Group ◽  
Plasminogen Activation ◽  
Healthy Individuals ◽  
Ligneous Conjunctivitis ◽  
Activation Assay ◽  
Tissue Plasminogen ◽  
Plasminogen Deficiency ◽  
Underlying Mechanisms

Abstract Background Ligneous conjunctivitis (LC) is a rare disorder associated with plasminogen deficiency characterized by chronic fibrin deposits in the eyelids. All patients with plasminogen deficiency do not develop LC, whose underlying mechanisms remain unknown. Objective We investigated whether fibrinolytic activity was correlated with phenotype and/or genotype in patients suffering from LC and their relatives. Methods Plasminogen activity/antigen levels and PLG mutations were determined in 10 patients with LC, 17 of their asymptomatic relatives, and 10 healthy individuals used as a control group. Plasma fibrinolytic activity was evaluated using three different assays: (1) tissue-plasminogen activator (t-PA) front lysis, (2) cell-based urokinase-dependent euglobulin clot lysis (ECLT) at the surface of corneal cells, and (3) urokinase-dependent plasminogen activation. Results Plasminogen activity varied from <10 to 40% in patients, 36 to 105% in relatives, and >80% in control healthy individuals. Homozygous K19E mutation was associated with normal antigenic plasminogen levels. In front-lysis experiments, all patients had a lower fibrinolysis rate as compared with their relatives and to control individuals. The cell-based ECLT and plasminogen activation assay demonstrated that urokinase-mediated fibrinolysis was not impaired in patients with homozygous K19E mutation compared with the other mutants. Conclusion We confirm that plasminogen levels fail to predict LC occurrence. In these conditions, t-PA clot lysis front is useful to predict clinical outcome in plasminogen deficiency. Moreover, we provide evidence that occurrence of LC overlaps quantitative and qualitative plasminogen deficiencies. The homozygous K19E mutation is associated with isolated impaired t-PA-mediated fibrinolysis compared with other mutants.

scholarly journals Preparation of Peptide and Recombinant Tissue Plasminogen Activator Conjugated Poly(Lactic-Co-Glycolic Acid) (PLGA) Magnetic Nanoparticles for Dual Targeted Thrombolytic Therapy

2020 ◽  
Vol 21 (8) ◽  
pp. 2690 ◽  
Author(s):  
Huai-An Chen ◽  
Yunn-Hwa Ma ◽  
Tzu-Yuan Hsu ◽  
Jyh-Ping Chen
Keyword(s):  
Magnetic Nanoparticles ◽  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Glycolic Acid ◽  
Blood Clot ◽  
Recombinant Tissue Plasminogen Activator ◽  
Clot Lysis ◽  
High Dose ◽  
Tissue Plasminogen

Recombinant tissue plasminogen activator (rtPA) is the only thrombolytic agent that has been approved by the FDA for treatment of ischemic stroke. However, a high dose intravenous infusion is required to maintain effective drug concentration, owing to the short half-life of the thrombolytic drug, whereas a momentous limitation is the risk of bleeding. We envision a dual targeted strategy for rtPA delivery will be feasible to minimize the required dose of rtPA for treatment. For this purpose, rtPA and fibrin-avid peptide were co-immobilized to poly(lactic-co-glycolic acid) (PLGA) magnetic nanoparticles (PMNP) to prepare peptide/rtPA conjugated PMNPs (pPMNP-rtPA). During preparation, PMNP was first surface modified with avidin, which could interact with biotin. This is followed by binding PMNP-avidin with biotin-PEG-rtPA (or biotin-PEG-peptide), which was prepared beforehand by binding rtPA (or peptide) to biotin-PEG-maleimide while using click chemistry between maleimide and the single –SH group in rtPA (or peptide). The physicochemical property characterization indicated the successful preparation of the magnetic nanoparticles with full retention of rtPA fibrinolysis activity, while biological response studies underlined the high biocompatibility of all magnetic nanoparticles from cytotoxicity and hemolysis assays in vitro. The magnetic guidance and fibrin binding effects were also confirmed, which led to a higher thrombolysis rate in vitro using PMNP-rtPA or pPMNP-rtPA when compared to free rtPA after static or dynamic incubation with blood clots. Using pressure-dependent clot lysis model in a flow system, dual targeted pPMNP-rtPA could reduce the clot lysis time for reperfusion by 40% when compared to free rtPA at the same drug dosage. From in vivo targeted thrombolysis in a rat embolic model, pPMNP-rtPA was used at 20% of free rtPA dosage to restore the iliac blood flow in vascular thrombus that was created by injecting a blood clot to the hind limb area.

Effect of sperm pretreatment with sodium hydroxide and dithiothreitol on the efficiency of bovine intracytoplasmic sperm injection

2014 ◽  
Vol 26 (6) ◽  
pp. 847 ◽  
Author(s):  
M. E. Arias ◽  
R. Sánchez ◽  
J. Risopatrón ◽  
L. Pérez ◽  
R. Felmer
Keyword(s):  
Embryonic Development ◽  
Intracytoplasmic Sperm Injection ◽  
Membrane Integrity ◽  
Control Group ◽  
Developmental Potential ◽  
Bovine Spermatozoa ◽  
Pronuclear Formation ◽  
First Time ◽  
In Vitro Embryonic Development

The efficiency of intracytoplasmic sperm injection (ICSI) in bovines is lower than in other species due, in part, to a lack of optimal conditions for its implementation; this has hindered the achievement of high rates of embryonic development and the birth of live offspring. The aim of the present study was to evaluate the effects of pretreatment of bovine spermatozoa with NaOH and dithiothreitol (DTT) on the viability, plasma membrane integrity, DNA fragmentation and in vitro developmental potential of embryos generated by ICSI. Following pretreatment of spermatozoa with 5 mM DTT for 20 min and a low concentration of NaOH (1 mM for 60 min), there were fewer live and acrosome reacted spermatozoa (44% and 34%, respectively) than in the control group without treatment (82%). Spermatozoa subjected to higher alkali concentrations (10–50 mM) were mostly dead and reacted. However, pronuclear formation, cleavage, blastocyst rate and embryo quality did not differ between these pretreatment groups and the untreated control group. In conclusion, we have described, for the first time, the effects of NaOH treatment on bovine spermatozoa and subsequent in vitro embryonic development after ICSI, and have demonstrated that pretreatment of bovine spermatozoa with NaOH or DTT is not necessary for an appropriate in vitro embryo development in this species.

Haemostatic safety of a unique recombinant plasmin molecule lacking kringles 2–5

2010 ◽  
Vol 104 (10) ◽  
pp. 780-787 ◽  
Author(s):  
Steve Manyak ◽  
Theresa Gruber ◽  
Abha Goyal ◽  
Guillermo Moreno ◽  
Jennifer Hunt ◽  
...  
Keyword(s):  
Bleeding Time ◽  
Rabbit Model ◽  
Full Length ◽  
Clot Lysis ◽  
Protease Domain ◽  
Serine Protease Domain ◽  
Tissue Plasminogen ◽  
Blinded Manner ◽  
Safety Advantage

SummaryWe previously demonstrated a significant margin of haemostatic safety for full-length plasmin in comparison with tissue plasminogen activator (t-PA). We now report studies that compare haemostatic safety of full-length plasmin with a novel recombinant plasmin derivative, (Δ K2–5) plasmin, consisting of kringle 1 linked to the serine protease domain of plasmin. Agent was administered intravenously in a randomised, blinded manner in a rabbit model of fibrinolytic haemorrhage. A dose-related decrease in α2-antiplasmin, factor VIII, and fibrinogen followed administration of 1.8, 2.7, 3.7 and 4.6 mg/kg of (Δ K2–5) plasmin, with nadir fibrinogen concentrations of 65%, 40%, 30%, and 0% of initial levels, respectively. Mean primary bleeding time was undisturbed at 1.8 mg/kg (2.2 ± 0.7 minutes), minimally prolonged at 2.7 or 3.7 mg/kg (5 ± 2.9 and 4.4 ± 2.2 minutes), and prolonged at the purposefully toxic 4.6 mg/kg dose (12.8 ± 18.8 minutes). Equimolar amounts of (Δ K2–5) plasmin and full-length plasmin had equal in vitro clot lysis efficacy, but in the bleeding model, (Δ K2–5) plasmin showed better haemostatic competency than full-length plasmin. This safety advantage may be explained by higher residual amounts of plasma fibrinogen in animals given (Δ K2–5) plasmin rather than full-length plasmin. We demonstrate that a unique recombinant plasmin mutant, (Δ K2–5) plasmin, possesses an advantage in hemostatic safety over an equimolar amount of full-length plasmin.

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