scholarly journals The Influence of a Knitted Hydrophilic Prosthesis of Blood Vessels on the Activation of Coagulation System—In Vitro Study

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1600
Author(s):  
Maria Szymonowicz ◽  
Maciej Dobrzynski ◽  
Sara Targonska ◽  
Agnieszka Rusak ◽  
Zbigniew Rybak ◽  
...  
Keyword(s):  
Blood Vessels ◽  
Initial Period ◽  
In Vitro Study ◽  
Vascular Prosthesis ◽  
Coagulation System ◽  
Factor Xii ◽  
Scanning Calorimetry ◽  
Vascular Prostheses ◽  
Control Value

The replacement of affected blood vessels of the polymer material can cause imbalances in the blood haemostatic system. Changes in blood after the implantation of vascular grafts depend not only on the chemical composition but also on the degree of surface wettability. The Dallon® H unsealed hydrophilic knitted vascular prosthesis double velour was assessed at work and compare with hydrophobic vascular prosthesis Dallon®. Spectrophotometric studies were performed in the infrared and differential scanning calorimetry, which confirmed the effectiveness of the process of modifying vascular prostheses. Determination of the parameters of coagulation time of blood after contact in vitro with Dallon® H vascular prosthesis was also carried out. Prolongation of activated thromboplastin time, decreased activity of factor XII, IX and VIII, were observed. The prolonged thrombin and fibrinogen were reduced in the initial period of the experiment. The activity of plasminogen and antithrombin III and protein C were at the level of control value. The observed changes in the values of determined parameters blood coagulation do not exceed the range of referential values for those indexes. The observed changes are the result of considerable blood absorptiveness by the prosthesis of blood vessels and their sealing.

In Vitro Effects of Urokinase — Prevention by Different Inhibitors

1990 ◽  
Vol 64 (03) ◽  
pp. 402-406 ◽  
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.

scholarly journals Poly(δ-valerolactone)/Poly(ethylene-co-vinylalcohol)/β-Tricalcium Phosphate Composite as Scaffolds: Preparation, Properties, and In Vitro Amoxicillin Release

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 46
Author(s):  
Mohammed Badwelan ◽  
Mohammed Alkindi ◽  
Osama Alghamdi ◽  
Waseem Sharaf Saeed ◽  
Abdel-Basit Al-Odayni ◽  
...  
Keyword(s):  
Hybrid Materials ◽  
Tricalcium Phosphate ◽  
Drug Carrier ◽  
Human Mesenchymal Stem Cells ◽  
In Vitro Study ◽  
Micro Computed Tomography ◽  
Scanning Calorimetry ◽  
Sem Images ◽  
Poly Ethylene

Two poly(δ-valerolactone)/poly(ethylene-co-vinylalcohol)/β-tricalcium phosphate (PEVAL/PDVAL/β-TCP) composites containing an equal ratio of polymer and filled with 50 and 70 wt% of β-TCP microparticles were prepared by the solvent casting method. Interconnected pores were realized using the salt leached technique, and the porosity of the resulted composites was evaluated by the scanning electron microscopy (SEM) method. The homogeneity of the hybrid materials was investigated by differential scanning calorimetry (DSC) and X-ray diffraction (XRD) analysis. The prepared materials’ SEM images showed interconnected micropores that respond to the conditions required to allow their uses as scaffolds. The porosity of each scaffold was determined from micro computed tomography (micro-CT) data, and the analysis of the mechanical properties of the prepared materials was studied through the stress-strain compressive test. The proliferation test results used human mesenchymal stem cells (MSCs) to grow and proliferate on the different types of prepared materials, reflecting that the hybrid materials were non-toxic and could be biologically acceptable scaffolds. The antibacterial activity test revealed that incorporation of amoxicillin in the specimens could inhibit the bacterial growth of S. aureus. The in vitro study of the release of amoxicillin from the PEVAL/PDVAL/amoxicillin and PEVAL/PDVAL/β-TCP/amoxicillin drug carrier systems in pH media 7.4, during eight days, gave promising results, and the antibiotic diffusion in these scaffolds obeys the Fickian model.

scholarly journals Poly(Glycerol Succinate) as an Eco-Friendly Component of PLLA and PLCL Fibres towards Medical Applications

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1731
Author(s):  
Dorota Kolbuk ◽  
Oliwia Jeznach ◽  
Michał Wrzecionek ◽  
Agnieszka Gadomska-Gajadhur
Keyword(s):  
Mechanical Properties ◽  
In Vitro Study ◽  
Medical Applications ◽  
Crystal Formation ◽  
Scanning Calorimetry ◽  
Chain Mobility ◽  
X Ray Scattering ◽  
Crystallisation Behaviour ◽  
Main Component

This study was conducted as a first step in obtaining eco-friendly fibres for medical applications using a synthesised oligomer poly(glycerol succinate) (PGSu) as an additive for synthetic poly(L-lactic acid) (PLLA) and poly (L-lactide-co-caprolactone) (PLCL). The effects of the oligomer on the structure formation, morphology, crystallisation behaviour, and mechanical properties of electrospun bicomponent fibres were investigated. Nonwovens were investigated by means of scanning electron microscopy (SEM), wide angle X-ray scattering (WAXS), differential scanning calorimetry (DSC), and mechanical testing. The molecular structure of PLLA fibres is influenced by the presence of PGSu mainly acting as an enhancer of molecular orientation. In the case of semicrystalline PLCL, chain mobility was enhanced by the presence of PGSu molecules, and the crystallinity of bicomponent fibres increased in relation to that of pure PLCL. The mechanical properties of bicomponent fibres were influenced by the level of PGSu present and the extent of crystal formation of the main component. An in vitro study conducted using L929 cells confirmed the biocompatible character of all bicomponent fibres.

scholarly journals Tigecycline Interferes with Fibrinogen Polymerization Independent of Peripheral Interactions with the Coagulation System

Antibiotics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 84 ◽  
Author(s):  
Anna Brandtner ◽  
Mirjam Bachler ◽  
Dietmar Fries ◽  
Martin Hermann ◽  
Jacqueline Ruehlicke ◽  
...  
Keyword(s):  
Qualitative Difference ◽  
In Vitro Study ◽  
Inhibitory Effect ◽  
Coagulation System ◽  
Mitochondrial Activity ◽  
Hepatic Cells ◽  
Spiked Plasma ◽  
Fibrin Network ◽  
Coagulation Tests

Tigecycline offers broad anti-bacterial coverage for critically ill patients with complicated infections. A described but less researched side effect is coagulopathy. The aim of this study was to test whether tigecycline interferes with fibrinogen polymerization by peripheral interactions. To study the effect of unmetabolized tigecycline, plasma of healthy volunteers were spiked with increasing concentrations of tigecycline. In a second experimental leg, immortalized human liver cells (HepG2) were treated with the same concentrations to test an inhibitory effect of hepatic tigecycline metabolites. Using standard coagulation tests, only the activated thromboplastin time in humane plasma was prolonged with increasing concentrations of tigecycline. Visualization of the fibrin network using confocal live microscopy demonstrated a qualitative difference in tigecycline treated experiments. Thrombelastometry and standard coagulation tests did not indicate an impairment of coagulation. Although the discrepancy between functional and immunologic fibrinogen levels increased in cell culture assays with tigecycline concentration, fibrinogen levels in spiked plasma samples did not show significant differences determined by functional versus immunologic methods. In our in vitro study, we excluded a direct effect of tigecycline in increasing concentrations on blood coagulation in healthy adults. Furthermore, we demonstrated a rapid loss of mitochondrial activity in hepatic cells with supra-therapeutic tigecycline dosages.

scholarly journals Overexpression of miR-24 Is Involved in the Formation of Hypocoagulation State after Severe Trauma by Inhibiting the Synthesis of Coagulation Factor X

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Lu-Jia Chen ◽  
Lian Yang ◽  
Xing Cheng ◽  
Yin-Kai Xue ◽  
Li-Bo Chen
Keyword(s):  
Negative Correlation ◽  
Major Trauma ◽  
Injury Severity ◽  
Coagulation Factor ◽  
In Vitro Study ◽  
Severe Trauma ◽  
Trauma Patients ◽  
Factor Xii ◽  
Factor X

Background. Dysregulation of microRNAs may contribute to the progression of trauma-induced coagulopathy (TIC). We aimed to explore the biological function that miRNA-24-3p (miR-24) might have in coagulation factor deficiency after major trauma and TIC. Methods. 15 healthy volunteers and 36 severe trauma patients (Injury Severity Score ≥ 16 were enrolled. TIC was determined as the initial international normalized ratio >1.5. The miR-24 expression and concentrations of factor X (FX) and factor XII in plasma were measured. In vitro study was conducted on L02 cell line. Results. The plasma miR-24 expression was significantly elevated by 3.17-fold (P=0.043) in major trauma patients and reduced after 3 days (P<0.01). The expression level was significantly higher in TIC than in non-TIC patients (P=0.040). Multivariate analysis showed that the higher miR-24 expression was associated with TIC. The plasma concentration of FX in TIC patients was significantly lower than in the non-TIC ones (P=0.030) and controls (P<0.01). A negative correlation was observed between miR-24 and FX. miR-24 transduction significantly reduced the FX level in the supernatant of L02 cells (P=0.030). Conclusions. miR-24 was overexpressed in major trauma and TIC patients. The negative correlation of miR-24 with FX suggested the possibility that miR-24 might inhibit the synthesis of FX during TIC.

Solidification of Nanostructured Lipid Carriers Loaded Testosterone Undecanoate: In Vivo and In Vitro Study

Drug Research ◽  
2018 ◽  
Vol 68 (08) ◽  
pp. 457-464
Author(s):  
Yabing Hua ◽  
Wanqing Li ◽  
Zhou Cheng ◽  
Ziming Zhao ◽  
Xiaoxing Yin ◽  
...  
Keyword(s):  
In Vitro Study ◽  
Cell Permeability ◽  
Vacuum System ◽  
Protective Agent ◽  
Scanning Calorimetry ◽  
Testosterone Undecanoate ◽  
Transmission Electron ◽  
Dissolution In Vitro

To enhance the bioavailability of testosterone undecanoate (TU) and overcome the current problem of soft capsules (Andriol Testocaps®), Nano-structured lipid carriers (NLC) for TU was developed. First, suspension of TU-loaded NLC (TU-NLC) was prepared by high pressure homogenization; then adsorbent or a protective agent β-cyclodextrin was used to solidify the suspension through a vacuum system; finally, the solid powder of TU-loaded NLC (solid TU-NLC) was filled into hard capsules. The characteristics of solid TU-NLC, were investigated in vitro and vivo. The particle size of TU-NLC was about 273.3 nm, the potential was 0.156±0.04. Transmission electron microscope (TEM) revealed that the NLC was spherical and uniform. Differential scanning calorimetry (DSC) suggested the drug had been encapsulated into NLC lipid matrix. The drug release proved that solid TU-NLC showed a higher dissolution in vitro. The CaCO-2 cell permeability showed that solid TU-NLC could enhance trans-membrane absorption of the TU. Moreover, the AUC of solid TU-NLC formulations (4304±550.50 μg/L*min) was higher than commercial product Andriol Testocaps® (3075±372.50 μg/L*min). In conclusion, solid TU-NLC could enhance the rate of dissolution, and had a relatively higher bioavailability than Andriol Testocaps® in vivo Graphical Abstract.

scholarly journals In Vitro Fatigue Properties of Prototype Woven Vascular Prosthesis with Poly (trimethylene terephthalate) Filaments as Circumferential Yarns

2012 ◽  
Vol 7 (4) ◽  
pp. 155892501200700
Author(s):  
Ying Chen ◽  
Xin Ding ◽  
Yuling Li ◽  
Xueqian Zhao
Keyword(s):  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Vascular Prosthesis ◽  
Fatigue Properties ◽  
Vascular Prostheses ◽  
Initial Modulus ◽  
Before And After ◽  
Show Evidence ◽  
Improve Compliance

As far as we know, fatigue properties of woven vascular prosthesis with PTT filaments as circumferential yarns which could improve compliance due to their lower initial modulus and better elasticity had not yet studied. In this study viscoelastic properties of PTT filaments were studied and fatigue properties of woven vascular prostheses with PTT filaments as circumferential yarns were tested using an accelerated fatigue tester. The changes of each property before and after the fatigue testing show evidence of fatigue. It will be more evidence of fatigue with increasing fatigue cycles and PTT tubular samples show better fatigue behavior compared to PET tubular samples.

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