A systematic characterization of the factors influencing polymerization and dynamic behavior of n-butyl cyanoacrylate

2017 ◽  
Vol 10 (2) ◽  
pp. 150-155 ◽  
Author(s):  
Bill H Wang ◽  
Melfort Boulton ◽  
Donald H Lee ◽  
David M Pelz ◽  
Stephen P Lownie
Keyword(s):  
Video Analysis ◽  
High Speed ◽  
Contact Angles ◽  
Polymerization Rate ◽  
Aqueous Environment ◽  
Complication Rates ◽  
Polymerization Time ◽  
High Speed Video

IntroductionBrain arteriovenous malformations are abnormal connections between arteries and veins without an intervening capillary bed. Endovascular glue embolization with N-butyl cyanoacrylate (NBCA) is an accepted form of treatment. The reported complication rates vary widely from 2% to 15%, and timing of polymerization appears to play a major role. Additionally, the interaction between NBCA and vessel surface as well as the presence of biological catalysts are poorly understood.MethodsPolymerization time was measured for mixtures of Lipiodol/NBCA of 50/50, 70/30, and 60/40. The influence of pH, temperature, and the presence of biological catalysts on polymerization time was investigated. Contact angles were measured on polyvinyl alcohol cryogel (PVA-C), silicone, and endothelial surfaces in a submerged aqueous environment to assess physical surface interactions. High speed video analysis of glue injection through a microcatheter was performed to characterize simulated coaxial flow.ResultsNBCA polymerization rate increased with pH and temperature. A hydrophilic surface such as PVA-C was better than silicone at mimicking the physical properties of endothelium. Live endothelium provided a catalytic surface that at least doubled the rate of polymerization. Blood products further increased the polymerization rate in the following order (slowest to fastest): plasma, platelets, red blood cells (RBCs), and lysed RBCs. These factors could explain the discrepancy between in vitro and in vivo results reported in the current literature. High speed video analysis of NBCA injection showed dripping to jetting transition with significant wall effect which deviated from previous ideal assumptions.ConclusionsThe determinants of NBCA polymerization rate are multifactorial and dependent mainly on the presence of biological catalysts coupled with flow related wall interaction.

F.05 Characterization of NBCA glue polymerization for embolization of brain AVM’s

2016 ◽  
Vol 43 (S2) ◽  
pp. S19-S20
Author(s):  
BH Wang ◽  
D Pelz ◽  
D Lee ◽  
MR Boulton ◽  
SP Lownie
Keyword(s):  
High Speed ◽  
Contact Angles ◽  
Polymerization Rate ◽  
Physical Interaction ◽  
Wide Range ◽  
Glue Injection ◽  
Glue Embolization

Background: Brain arteriovenous malformations (AVM’s) are abnormal connections between arteries and veins. Endovascular glue embolization with N-butyl cyanoacrylate (NBCA) is an accepted form of treatment, with most complications related to timing of polymerization. Current literature reports a wide range of polymerization times with large discrepancies between in-vivo and in-vitro results. Methods: Polymerization time was measured for mixtures of lipiodol/NBCA of 50/50, 60/40, 70/30. The influence of pH, temperature and presence of biological catalysts on polymerization rate was investigated in-vivo using submerged droplet tests. PVA-C, silicone and endothelium surfaces were compared and contact angles were measured to assess physical interaction with NBCA. High-speed video of glue injection through a microcatheter was captured to characterize coaxial flow. Results: Polymerization rate increases with pH and temperature. A hydrophilic substrate such as PVA-C provides surface properties that are most similar to endothelium. Endothelium provides a catalytic surface that increases the rate of polymerization. Blood products further increase the polymerization rate with RBC’s providing almost instantaneous polymerization of NBCA upon contact. Characterization of coaxial flow shows dripping to jetting transition with significant wall effect. Conclusions: We have successfully deconstructed and characterized the dynamic behavior of NBCA embolization. A refined understanding of NBCA behavior could help reduce embolization-related complications.

scholarly journals Effects of temperature alteration on viscosity, polymerization, and in-vivo arterial distribution of N-butyl cyanoacrylate-iodized oil mixtures

2021 ◽  
Author(s):  
Takahiko Mine ◽  
Daisuke Yasui ◽  
Hidemasa Saito ◽  
Tatsuo Ueda ◽  
Taro Yokoyama ◽  
...  
Keyword(s):  
High Speed ◽  
Video Camera ◽  
Polymerization Time ◽  
Iodized Oil ◽  
High Speed Video Camera ◽  
Oil Mixtures ◽  
Potential Factors ◽  
Peripheral Arterial

Abstract Purpose Temperature alteration can modify the polymerization of n-butyl cyanoacrylate (NBCA)-iodized oil mixtures during vascular embolization; its effects on viscosity, polymerization time, and intra-arterial distribution of the NBCA-iodized oil mixture were investigated. Materials and methods In vitro, the viscosities of NBCA, iodized oil, and NBCA-iodized oil mixtures (ratio, 1:1–8) were measured at 4–60 ºC using a rotational rheometer. The polymerization times (from contact with blood plasma to stasis) were recorded at 0–60 ºC using a high-speed video camera. In vivo, the 1:2 mixture was injected into rabbit renal arteries at 0, 20, and 60 ºC; intra-arterial distribution of the mixture was pathologically evaluated. Results The mixtures’ viscosities decreased as temperature increased; those at 60 ºC were almost four to five times lower than those at 4 ºC. The polymerization time of NBCA and the 1:1–4 mixtures increased as temperature decreased in the 0–30 ºC range; the degree of time prolongation increased as the percentage of iodized oil decreased. The 0 ºC group demonstrated distributions of the mixture within more peripheral arterial branches than the 20 and 60 ºC groups. Conclusion Warming reduces the mixture’s viscosity; cooling prolongs polymerization. Both can be potential factors to improve the handling of NBCA-iodized oil mixtures for lesions requiring peripheral delivery. Secondary abstract Temperature alteration influences the polymerization time, viscosity, and intra-arterial distribution of NBCA-iodized oil mixtures. Warming reduces the viscosity of the mixture, while cooling prolongs polymerization.

scholarly journals Coherent Raman Scattering Microscopy in Oncology Pharmacokinetic Research

2021 ◽  
Vol 12 ◽  
Author(s):  
Junjie Zeng ◽  
Wenying Zhao ◽  
Shuhua Yue
Keyword(s):  
Raman Scattering ◽  
High Speed ◽  
Cancer Drug ◽  
Cancer Drugs ◽  
High Speed Imaging ◽  
Coherent Raman Scattering ◽  
Anti Cancer ◽  
Coherent Raman

The high attrition rates of anti-cancer drugs during clinical development remains a bottleneck problem in pharmaceutical industry. This is partially due to the lack of quantitative, selective, and rapid readouts of anti-cancer drug activity in situ with high resolution. Although fluorescence microscopy has been commonly used in oncology pharmacological research, fluorescent labels are often too large in size for small drug molecules, and thus may disturb the function or metabolism of these molecules. Such challenge can be overcome by coherent Raman scattering microscopy, which is capable of chemically selective, highly sensitive, high spatial resolution, and high-speed imaging, without the need of any labeling. Coherent Raman scattering microscopy has tremendously improved the understanding of pharmaceutical materials in the solid state, pharmacokinetics of anti-cancer drugs and nanocarriers in vitro and in vivo. This review focuses on the latest applications of coherent Raman scattering microscopy as a new emerging platform to facilitate oncology pharmacokinetic research.

230 GENERATION OF PUTATIVE RABBIT EMBRYONIC STEM CELLS

2007 ◽  
Vol 19 (1) ◽  
pp. 231
Author(s):  
S. Wang ◽  
X. Tang ◽  
Y. Niu ◽  
H. Chen ◽  
T. Li ◽  
...  
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
High Speed ◽  
Es Cells ◽  
Research Work ◽  
Embryonic Stem ◽  
Morphological Characteristics ◽  
Mouse Escs

The rabbit, as a laboratory animal model, has several advantages in the study of human physiological disorders. In this study, stable putative pluripotent rabbit embryonic stem cells (rESCs) were derived from in vivo-fertilized and in vitro-cultured blastocysts. The rabbit ICMs were obtained by 0.05% trypsin–0.008% EDTA treatment and mechanical separation; the ES-like cell colonies seen several days later. ICM-derived outgrowths which were treated with 5 mg/mL-1 dispase, followed by 0.05% trypsin–0.008% EDTA, were mechanically disaggregated into small clumps and reseeded on MEFs. The putative ES cell lines maintained expression of pluripotent cells markers and normal XY karyotype for long periods of culture (>1 month). The putative rESCs expressed alkaline phosphatase, transcription factor Oct-4, stage-specific embryonic antigens (SSEA-1, SSEA-3, and SSEA-4), and tumor-related antigens (TRA-1-60 and TRA-1-81). The morphological characteristics of the putative ESCs are closer to those of human ESCs; their high speed of proliferation, however, is closer to that of mouse ESCs. Putative rabbit ESCs were induced to differentiate into many cell types including trophoblast cells, similar to primate ESCs, in vitro, and formed teratomas with derivatives of the 3 major germ layers in vivo when injected into SCID mice. Using RT-PCR measurement, but with some differences in ligands and inhibitors, and comparing with human and mouse ESCs, the putative rabbit ESCs expressed similar genes related to pluripotency (Oct-4, Nanog, SOX2, and UTF-1) and similar genes of FGF, WNT, and TGF signaling pathways related to the proliferation and self-renewal. Our further research work showed that TGF beta and FGF pathways cooperate to maintain pluripotency of rabbit ESCs similar to those of human ES cells.

scholarly journals VPS4 triggers constriction and cleavage of ESCRT-III helical filaments

2019 ◽  
Vol 5 (4) ◽  
pp. eaau7198 ◽  
Author(s):  
Sourav Maity ◽  
Christophe Caillat ◽  
Nolwenn Miguet ◽  
Guidenn Sulbaran ◽  
Gregory Effantin ◽  
...  
Keyword(s):  
High Speed ◽  
Membrane Structures ◽  
Vesicle Budding ◽  
Endosomal Sorting ◽  
Force Microscopy ◽  
Cellular Processes ◽  
Membrane Fission ◽  
End Caps

Many cellular processes such as endosomal vesicle budding, virus budding, and cytokinesis require extensive membrane remodeling by the endosomal sorting complex required for transport III (ESCRT-III). ESCRT-III protein family members form spirals with variable diameters in vitro and in vivo inside tubular membrane structures, which need to be constricted to proceed to membrane fission. Here, we show, using high-speed atomic force microscopy and electron microscopy, that the AAA-type adenosine triphosphatase VPS4 constricts and cleaves ESCRT-III CHMP2A-CHMP3 helical filaments in vitro. Constriction starts asymmetrically and progressively decreases the diameter of CHMP2A-CHMP3 tubular structure, thereby coiling up the CHMP2A-CHMP3 filaments into dome-like end caps. Our results demonstrate that VPS4 actively constricts ESCRT-III filaments and cleaves them before their complete disassembly. We propose that the formation of ESCRT-III dome-like end caps by VPS4 within a membrane neck structure constricts the membrane to set the stage for membrane fission.

scholarly journals 3D Printed Biomodels for Flow Visualization in Stenotic Vessels: An Experimental and Numerical Study

Micromachines ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 549
Author(s):  
Violeta Carvalho ◽  
Nelson Rodrigues ◽  
Ricardo Ribeiro ◽  
Pedro F. Costa ◽  
Rui A. Lima ◽  
...  
Keyword(s):  
High Speed ◽  
Complex Disease ◽  
Numerical Study ◽  
Numerical Data ◽  
In Vivo Studies ◽  
Physiological Variables ◽  
Microscopy Technique ◽  
Dynamics Simulations

Atherosclerosis is one of the most serious and common forms of cardiovascular disease and a major cause of death and disability worldwide. It is a multifactorial and complex disease that promoted several hemodynamic studies. Although in vivo studies more accurately represent the physiological conditions, in vitro experiments more reliably control several physiological variables and most adequately validate numerical flow studies. Here, a hemodynamic study in idealized stenotic and healthy coronary arteries is presented by applying both numerical and in vitro approaches through computational fluid dynamics simulations and a high-speed video microscopy technique, respectively. By means of stereolithography 3D printing technology, biomodels with three different resolutions were used to perform experimental flow studies. The results showed that the biomodel printed with a resolution of 50 μm was able to most accurately visualize flow due to its lowest roughness values (Ra = 1.8 μm). The flow experimental results showed a qualitatively good agreement with the blood flow numerical data, providing a clear observation of recirculation regions when the diameter reduction reached 60%.

Sign in / Sign up

Export Citation Format

Share Document