scholarly journals In Vivo Animal Study of a Highly Viscous N-butyl Cyanoacrylate Medical Adhesive for Intravenous Embolization

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3527
Author(s):  
Jae-Won Seo ◽  
Habeen Park ◽  
Dogeun Kim ◽  
Seoyun Lee ◽  
Young Gook Koh ◽  
...  
Keyword(s):  
Foreign Body Reaction ◽  
Vascular Occlusion ◽  
High Viscosity ◽  
Polymerization Reaction ◽  
Embolic Agent ◽  
Low Viscosity ◽  
Vein Occlusion ◽  
Lower Heat ◽  
Medical Adhesive

N-butyl cyanoacrylate (NBCA) is a liquid monomer that undergoes an exothermic polymerization reaction to form a solid upon initiation with hydroxyl anions. Recently, EGpresto, a highly viscous NBCA-based adhesive, has been developed for vascular-occlusion purposes. In this study, we investigated the heat of polymerization of EGpresto and compared the results with those of a low-viscosity NBCA glue. Results show that EGpresto exhibited a lower heat of polymerization (64 ± 7 °C vs. 34 ± 1 °C). This was due to its high viscosity, which resulted in a delayed polymerization time. To investigate the efficacy and safety of EGpresto for intravenous embolization, a 14 d in vivo animal test was conducted using three pigs. Five cc of EGpresto was injected into the epigastric vein of each animal. Complete postoperative vein occlusion was confirmed at 7 and 14 d by ultrasonographic visualization. After the animals were sacrificed, the operated and unoperated veins were exposed, and the injected adhesive was found without migration. During the histology, the injected adhesive was not found in the inner or outer vein walls, and the immune reactions seemed to be the only foreign-body reaction, showing that EGpresto is a non-toxic and safe intravascular embolic agent.

scholarly journals In vivo evaluation of the new PHIL low viscosity in a swine rete mirabile model

2018 ◽  
Vol 24 (6) ◽  
pp. 706-712 ◽  
Author(s):  
Edgar A Samaniego ◽  
Colin P Derdeyn ◽  
Minako Hayakawa ◽  
David Hasan ◽  
Santiago Ortega-Gutierrez
Keyword(s):  
Histological Analysis ◽  
Embolic Agent ◽  
In Vivo Evaluation ◽  
Rete Mirabile ◽  
Low Viscosity ◽  
Liquid Embolic ◽  
Optimal Average ◽  
The Right ◽  
Inflammatory Changes

Introduction Few liquid embolic materials are available for treatment of arteriovenous malformations. We describe the in vivo experience with the new PHIL low viscosity (LV) liquid embolic agent in a swine rete mirabile model. Methods Eight swine were treated. Two animals underwent embolization of a rete with PHIL LV and the contralateral rete with Squid 12 (euthanized the same day). Six animals underwent embolization of the right rete: two with balloon flow arrest (euthanized at 14 d) and four with a microcatheter alone (euthanized at 14 and 90 d). Performance characteristics of the embolic agents were evaluated. Microscopic and histological analysis of the harvested retia was performed. Macroscopic examinations and high contrast digital-based radiographs of the central nervous system were obtained. Results We did not experience any technical complication during embolization of each rete. Overall occlusion ability, on/off injection and ease to retrieve the microcatheter/balloon with PHIL LV were optimal. Fluoroscopic visualization of the PHIL LV cast was adequate to optimal. Average embolization time with flow arrest was 9.5 min versus 19.5 min with microcatheter plugging. Embolizations with PHIL LV required less volume and were shorter when compared to Squid 12. Subacute (14 d) and chronic (90 d) microscopic and histological analysis demonstrated minimal inflammatory changes in the perivascular tissues and permanent occlusion of the embolized vasculature. Conclusion In this swine rete model, the new PHIL LV embolic agent had an excellent embolization performance. Vessels embolized remained occluded up to 90 d from the procedure with minimal inflammatory changes.

scholarly journals In vivo Evaluation of Theophylline Sustained Release Matrix Tablets Containing Low Viscosity Guar Gum

2021 ◽  
Vol 71 (2) ◽  
Author(s):  
Rama Rao Tadikonda ◽  
Satyanarayana Sreemantula
Keyword(s):  
Drug Delivery ◽  
Guar Gum ◽  
Controlled Drug Delivery ◽  
High Viscosity ◽  
Matrix Tablets ◽  
In Vivo Studies ◽  
Blood Levels ◽  
In Vivo Evaluation ◽  
Low Viscosity

The present investigation was carried out to evaluate the utility of guar gum as a hydrophilic matrix carrier in the design of oral controlled drug delivery. Based on the earlier reports, the low viscosity guar gum appears to be superior to medium and high viscosity grades of guar gum in providing a sustained delivery of theophylline along the GI tract. Conducting in vivo studies on theophylline matrix tablets containing 10% of low viscosity guar gum as a representative formulation assessed the in vivo performance of the guar gum matrix tablets. The in vivo studies were carried out in dogs. The effective concentration of theophylline was sustained for a period of 16 hours. The extended tmax, reduced absorption rate constant, prolonged MRT, unchanged Cmax and unchanged bioavailability indicate a controlled release of theophylline from the guar gum matrix tablets resulting in a sustained absorption and prolonged blood levels of theophylline. The theophylline matrix tablets showed blood levels well below 15 ?g/mL indicating freedom from adverse effects. Based on the studies, guar gum appears to be a potential carrier in the design of oral controlled drug delivery systems.

scholarly journals Combination of Alcohol and EVOH as a New Embolic Agent: Midterm Tissue and Inflammatory Effects in a Swine Model

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Jean-François Hak ◽  
Farouk Tradi ◽  
Mickael Bobot ◽  
Pauline Brige ◽  
Paul Habert ◽  
...  
Keyword(s):  
Vascular Occlusion ◽  
Embolic Agent ◽  
Swine Model ◽  
Blood Alcohol ◽  
Alcohol Content ◽  
Ethylene Vinyl Alcohol ◽  
Blood Alcohol Content ◽  
Tubular Necrosis ◽  
Group 2 ◽  
Group 1

Objective. To evaluate the vascular occlusion and midterm tissue toxicity properties of a combination of ethylene-vinyl alcohol (EVOH) (Squid 18®) (75%) and alcohol (25%)—Alco-Squid 18—in a swine model. Materials and Methods. Alco-Squid 18 (75% Squid 18® mixed with 25% alcohol) (AS18) was compared to embolization with 96% alcohol alone and to embolization with Squid 18® (S18®) alone. An arteriovenous malformation (AVM) model was created in group 1 (n = 2). Each AVM model was then embolized with AS18 or S18® alone with evaluation of a ratio between the volume of embolic agent divided by the volume of the AVM (evaluated by CT). For group 2 (n = 5), each agent was tested on three different kidneys (upper pole kidney artery). Pre- and postinterventional CTs, angiographies, blood alcohol content dosages, and histological studies (3 months postintervention) were performed. Results. AS18 has better distal distribution than S18® alone, both in the kidneys (mean capsule-S18® distance: 3.9 mm (±0.23) and mean capsule-AS18 distance: 2.3 mm (±0.11) ( p = 0.029 ) and in the AVM model. Histological exploration found a higher rate of tubular necrosis with AS18 compared with S18® alone and alcohol alone (3.78 ± 0.44 compared to 2.33 ± 1.22 p   =  0 . 012 and 1.22 ± 0.67 p   < 0   . 0001 ). The blood alcohol content was negligible in all cases. Conclusion. AS18 can suggest a better distal sclerotic and embolic character as compared with S18® alone without systemic toxicity.

scholarly journals A Low-Viscosity BisGMA Derivative for Resin Composites: Synthesis, Characterization, and Evaluation of Its Rheological Properties

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 338
Author(s):  
Ali Alrahlah ◽  
Abdel-Basit Al-Odayni ◽  
Haifa Fahad Al-Mutairi ◽  
Bashaer Mousa Almousa ◽  
Faisal S. Alsubaie ◽  
...  
Keyword(s):  
Substantial Reduction ◽  
Triethylene Glycol ◽  
High Viscosity ◽  
Resin Matrix ◽  
Resonance Spectroscopy ◽  
Dental Resin ◽  
Triethylene Glycol Dimethacrylate ◽  
Oh Groups ◽  
Low Viscosity ◽  
13C Nuclear Magnetic Resonance

This study aimed to synthesize new bisphenol A-glycidyl methacrylate (BisGMA) derivatives, targeting a reduction in its viscosity by substituting one of its OH groups, the leading cause of its high viscosity, with a chlorine atom. Hence, this monochloro-BisGMA (mCl-BisGMA) monomer was synthesized by Appel reaction procedure, and its structure was confirmed using Fourier transform infrared spectroscopy, 1H and 13C-nuclear magnetic resonance spectroscopy, and mass spectroscopy. The viscosity of mCl-BisGMA (8.3 Pa·s) was measured under rheometry conditions, and it was found to be more than 65-fold lower than that of BisGMA (566.1 Pa·s) at 25 °C. For the assessment of the viscosity changes of model resins in the presence of mCl-BisGMA, a series of resin matrices, in which, besides BisGMA, 50 wt % was triethylene glycol dimethacrylate, were prepared and evaluated at 20, 25, and 35 °C. Thus, BisGMA was incrementally replaced by 25% mCl-BisGMA to obtain TBC0, TBC25, TBC50, TBC75, and TBC100 blends. The viscosity decreased with temperature, and the mCl-BisGMA content in the resin mixture increased. The substantial reduction in the viscosity value of mCl-BisGMA compared with that of BisGMA may imply its potential use as a dental resin matrix, either alone or in combination with traditional monomers. However, the various properties of mCl-BisGMA-containing matrices should be evaluated.

scholarly journals A bone replacement-type calcium phosphate cement that becomes more porous in vivo by incorporating a degradable polymer

2021 ◽  
Vol 32 (7) ◽  
Author(s):  
Akiyoshi Shimatani ◽  
Hiromitsu Toyoda ◽  
Kumi Orita ◽  
Yuta Ibara ◽  
Yoshiyuki Yokogawa ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Calcium Phosphate Cement ◽  
Alginic Acid ◽  
Setting Time ◽  
Zealand White Rabbit ◽  
Control Group ◽  
Degradable Polymer ◽  
Low Viscosity ◽  
Bone Replacement

AbstractThis study investigated whether mixing low viscosity alginic acid with calcium phosphate cement (CPC) causes interconnected porosity in the CPC and enhances bone replacement by improving the biological interactions. Furthermore, we hypothesized that low viscosity alginic acid would shorten the setting time of CPC and improve its strength. CPC samples were prepared with 0, 5, 10, and 20% low viscosity alginic acid. After immersion in acetate buffer, possible porosification in CPC was monitored in vitro using scanning electron microscopy (SEM), and the setting times and compressive strengths were measured. In vivo study was conducted by placing CPC in a hole created on the femur of New Zealand white rabbit. Microcomputed tomography and histological examination were performed 6 weeks after implantation. SEM images confirmed that alginic acid enhanced the porosity of CPC compared to the control, and the setting time and compressive strength also improved. When incorporating a maximum amount of alginic acid, the new bone mass was significantly higher than the control group (P = 0.0153). These biological responses are promising for the translation of these biomaterials and their commercialization for clinic applications.

scholarly journals A Conceptional Approach of Resin-Transfer-Molding to Rosin-Sourced Epoxy Matrix Green Composites

Aerospace ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 5
Author(s):  
Sicong Yu ◽  
Xufeng Zhang ◽  
Xiaoling Liu ◽  
Chris Rudd ◽  
Xiaosu Yi
Keyword(s):  
Composite Laminates ◽  
Resin Transfer Molding ◽  
High Viscosity ◽  
Ramie Fiber ◽  
Liquid Composite Molding ◽  
Curing Agent ◽  
Molding Process ◽  
Transfer Molding ◽  
Low Viscosity ◽  
Composite Molding

In this concept-proof study, a preform-based RTM (Resin Transfer Molding) process is presented that is characterized by first pre-loading the solid curing agent onto the preform, and then injecting the liquid nonreactive resin with an intrinsically low viscosity into the mold to infiltrate and wet the pre-loaded preform. The separation of resin and hardener helped to process inherently high viscosity resins in a convenient way. Rosin-sourced, anhydrite-cured epoxies that would normally be regarded as unsuited to liquid composite molding, were thus processed. Rheological tests revealed that by separating the anhydrite curing agent from a formulated RTM resin system, the remaining epoxy liquid had its flowtime extended. C-scan and glass transition temperature tests showed that the preform pre-loaded with anhydrite was fully infiltrated and wetted by the liquid epoxy, and the two components were diffused and dissolved with each other, and finally, well reacted and cured. Composite laminates made via this approach exhibited roughly comparable quality and mechanical properties with prepreg controls via autoclave or compression molding, respectively. These findings were verified for both carbon and ramie fiber composites.

Electrochemical Evaluation for Rust Preventive Properties of Rust Preventive Oils Coated on Fe-Cu-C Sintered Steel

2014 ◽  
Vol 783-786 ◽  
pp. 2537-2540 ◽  
Author(s):  
Satoshi Sunada ◽  
Norio Nunomura ◽  
Sayaka Hirata ◽  
Naoki Nagase
Keyword(s):  
Open Circuit Potential ◽  
High Viscosity ◽  
Open Circuit ◽  
Second Step ◽  
Sintered Steel ◽  
Corrosive Solution ◽  
The Third ◽  
Low Viscosity ◽  
Sintered Steels ◽  
Electrochemical Evaluation

Since Fe-Cu-C sintered steels are easily rusted, they are coated with rust preventive oils. High viscosity of those rust preventive oils decrease workability, and low viscosity deteriorates rust preventive performance. Therefore, it is necessary to develop new rust preventive oils with contradictory properties of low viscosity and superior rust prevention. However, precise methodology to evaluate rust prevention ability has not been established. In this study, we developed new technique to quantitatively evaluate rust prevention ability by measuring the open circuit potential through thin corrosive solution on Fe-Cu-C sintered steels coated with a rust preventive oils. As a result, the ability for rust prevention can be measured quantitatively, and it decreases slowly over time, with repeating destruction and restoration. Furthermore, it was found that the deteriorating processes of rust prevention ability for rust prevention oils are composed of three characteristics steps respectively. That is, in the first step the great open circuit potential changes from 0V to-0.3V with repetition were observed where the excellent rust prevention ability was kept, in the second step it decreases slowly from-0.1V to-0.4V with oscillation of the small potential changes where the gradual decrease of rust prevention ability was recognized and in the third step it decreases monotonously in the lower potential than-0.4V where the rust was observed because of the remarkable deteriorating of the rust prevention ability.

Retinal obliterative vasculitis associated to contralateral retinal neovascularization in membranoproliferative glomerulonephritis

2021 ◽  
pp. 112067212110143
Author(s):  
Michele Nicolai ◽  
Alessandro Franceschi ◽  
Nicola Vito Lassandro ◽  
Paolo Pelliccioni ◽  
Luca Danieli ◽  
...  
Keyword(s):  
Retinal Vein Occlusion ◽  
Branch Retinal Vein Occlusion ◽  
Membranoproliferative Glomerulonephritis ◽  
Vision Loss ◽  
Vascular Occlusion ◽  
Retinal Neovascularization ◽  
Vein Occlusion ◽  
Retinal Vascular Occlusion ◽  
Contralateral Eye ◽  
Peculiar Case

Purpose: To report our experience with a peculiar case of asynchronous bilateral retinal vascular occlusion in a patient suffering from membranoproliferative glomerulonephritis. Case report: A 57-year-old dialysed male affected by membranoproliferative glomerulonephritis who underwent kidney transplantation complained of a sudden vision loss in his right eye (RE). His best-corrected visual acuity (BCVA) was 20/40 in RE and 20/20 in the left eye (LE); ophthalmological and fluorangiographic examinations revealed unilateral retinal obliterative vasculitis with panuveitis and apparent sparing of contralateral eye. About 6 months later the patient developed a branch retinal vein occlusion associated with a papillary neovascular membrane in LE. Corticosteroid therapy was administered and immunosuppressant dosage was increased with macular oedema reduction in both events. Conclusion: We report a case of unilateral retinal obliterative vasculitis and subsequent contralateral retinal neovascularization and branch retinal vein occlusion in a patient affected by membranoproliferative glomerulonephritis.

Synthesis and Characterization of Polydimethylsiloxane (PDMS) with Medium Viscosity via Ring-Opening Polymerization

2021 ◽  
Vol 1028 ◽  
pp. 346-351
Author(s):  
Soni Setiadji ◽  
Zulfi Mofa Agasa ◽  
Diba G Auliya ◽  
Fitrilawati ◽  
Norman Syakir ◽  
...  
Keyword(s):  
Ring Opening ◽  
Vitreoretinal Surgery ◽  
High Viscosity ◽  
Ring Opening Polymerization ◽  
Vitreous Humour ◽  
Synthesis And Characterization ◽  
Low Viscosity ◽  
A Value ◽  
Medium Viscosity

Duration of use and injectability are external factors for Polydimethylsiloxane (PDMS) that needs to be considered when PDMS utilized as a vitreous substituted liquid in vitreoretinal surgery. In general, PDMS which has been used as a substitute for vitreous humour is PDMS with a low viscosity in the value about 1000 cSt and a high viscosity at a value of about 5000 cSt. Various deficiencies have been encountered from low and high viscosity of PDMS, causing research to be continued to obtain PDMS which has suitable properties as a substitute for vitreous humour. One of them is research to obtain medium viscosity of PDMS with a viscosity value of about 2000 cSt. Here, we reported synthesis and characterization of PDMS with medium viscosity in ranges from 1800 to 2600 mPas. PDMS was synthesized through Ring-Opening Polymerization (ROP) pathway using the monomer of Octamethylcyclotetrasiloxane (D4) and the chain terminator of Hexamethyldisiloxane (MM). Various concentrations of potassium hydroxide (KOH) of 3, 4, 6 and 8 %(w/v) were applied as initiator to form gel of PDMS. All synthesized PDMS samples were identified to have viscosity values of 1800-2600 mPas, refractive index values of 1.4042-1.4044 and surface tension values of 22-23 mN/m. Meanwhile, the results of Fourier-Transform Infrared (FTIR) measurement showed that the absorption peaks were similar to that of our previous report.

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