scholarly journals Drug delivery via tattooing: Effect of needle and fluid properties

2021 ◽  
Author(s):  
Idera Lawal ◽  
Pankaj Rohilla ◽  
Jeremy Marston

Tattooing is a commonplace practice among the general populace in which ink is deposited within dermal tissue. Typically, an array of needles punctures the skin which facilitates the delivery of a fluid within the dermis. Although, a few studies in the past have investigated the potential of tattooing as an intradermal (ID) drug injection technique, an understanding of the fluid dynamics involved in the delivery of fluid into skin is still lacking. Herein, we sought to provide insight into the process via an in vitro study. We utilize a five needle flat array (5F) with a tattoo machine to inject fluids into gelatin gels. High-speed imaging was used to visualize the injection process and estimate the amount of fluid delive red after each injection upto the 50th injection. We investigate the role of reciprocating frequency (f) of the needle array and the physical properties of the fluids on the volume (Vo) and the percentage delivery (η) after injection. In addition, we illustrate the physical mechanism of fluid infusion during tattooing, which has not been reported. An understanding of the injection process via tattooing can be useful in the development of ID tattoo injectors as drug delivery devices.

Perfusion ◽  
2017 ◽  
Vol 33 (1) ◽  
pp. 16-24 ◽  
Author(s):  
Tim Segers ◽  
Marco C. Stehouwer ◽  
Filip M.J.J. de Somer ◽  
Bastian A. de Mol ◽  
Michel Versluis

Introduction: Gaseous microemboli (GME) introduced during cardiac surgery are considered as a potential source of morbidity, which has driven the development of the first bubble counters. Two new generation bubble counters, introduced in the early 2000s, claim correct sizing and counting of GME. This in-vitro study aims to validate the accuracy of two bubble counters using monodisperse bubbles in a highly controlled setting at low GME concentrations. Methods: Monodisperse GME with a radius of 43 µm were produced in a microfluidic chip. Directly after their formation, they were injected one-by-one into the BCC200 and the EDAC sensors. GME size and count, measured with the bubble counters, were optically verified using high-speed imaging. Results: During best-case scenarios or low GME concentrations of GME with a size of 43 µm in radius in an in-vitro setup, the BCC200 overestimates GME size by a factor of 2 to 3 while the EDAC underestimates the average GME size by at least a factor of two. The BCC200 overestimates the GME concentration by approximately 20% while the EDAC overestimates the concentration by nearly one order of magnitude. Nevertheless, the calculated total GME volume is only over-predicted by a factor 2 since the EDAC underestimates the actual GME size. For the BCC200, the total GME volume was over-predicted by 25 times due to the over-estimation of GME size. Conclusions: The measured errors in the absolute sizing/counting of GME do not imply that all results obtained using the bubble counters are insignificant or invalid. A relative change in bubble size or bubble concentration can accurately be measured. However, care must be taken in the interpretation of the results and their absolute values. Moreover, the devices cannot be used interchangeably when reporting GME activity. Nevertheless, both devices can be used to study the relative air removal characteristics of CPB components or for the quantitative monitoring of GME production during CPB interventions.


2021 ◽  
Vol 165 ◽  
pp. 39
Author(s):  
Francesca Lombardi ◽  
Silvano Santini ◽  
Paola Palumbo ◽  
Valeria Cordone ◽  
Virginio Bignotti ◽  
...  

Author(s):  
Sarah McCarrick ◽  
Valentin Romanovski ◽  
Zheng Wei ◽  
Elin M. Westin ◽  
Kjell-Arne Persson ◽  
...  

AbstractWelders are daily exposed to various levels of welding fumes containing several metals. This exposure can lead to an increased risk for different health effects which serves as a driving force to develop new methods that generate less toxic fumes. The aim of this study was to explore the role of released metals for welding particle-induced toxicity and to test the hypothesis that a reduction of Cr(VI) in welding fumes results in less toxicity by comparing the welding fume particles of optimized Cr(VI)-reduced flux-cored wires (FCWs) to standard FCWs. The welding particles were thoroughly characterized, and toxicity (cell viability, DNA damage and inflammation) was assessed following exposure to welding particles as well as their released metal fraction using cultured human bronchial epithelial cells (HBEC-3kt, 5–100 µg/mL) and human monocyte-derived macrophages (THP-1, 10–50 µg/mL). The results showed that all Cr was released as Cr(VI) for welding particles generated using standard FCWs whereas only minor levels (< 3% of total Cr) were released from the newly developed FCWs. Furthermore, the new FCWs were considerably less cytotoxic and did not cause any DNA damage in the doses tested. For the standard FCWs, the Cr(VI) released in cell media seemed to explain a large part of the cytotoxicity and DNA damage. In contrast, all particles caused rather similar inflammatory effects suggesting different underlying mechanisms. Taken together, this study suggests a potential benefit of substituting standard FCWs with Cr(VI)-reduced wires to achieve less toxic welding fumes and thus reduced risks for welders.


2021 ◽  
Vol 104 ◽  
pp. 93-105
Author(s):  
Sikhumbuzo Charles Kunene ◽  
Kuen-Song Lin ◽  
Meng-Tzu Weng ◽  
Maria Janina Carrera Espinoza ◽  
Chun-Ming Wu

2017 ◽  
Vol 19 (suppl_6) ◽  
pp. vi250-vi250
Author(s):  
Anurag N Paranjape ◽  
Brunilde Gril ◽  
Stephan Woditschka ◽  
Jeffrey Hanson ◽  
Xiaolin Wu ◽  
...  

2016 ◽  
Vol 35 (14) ◽  
pp. 3176-3181
Author(s):  
Elham Sadat Mostafavi ◽  
Mohammad Ali Nasiri Khalili ◽  
Sirus Khodadadi ◽  
Gholam Hossein Riazi

2002 ◽  
Vol 16 (3) ◽  
pp. 552-562 ◽  
Author(s):  
Xiaoqin Xiang ◽  
Mingsheng Yuan ◽  
Ying Song ◽  
Neil Ruderman ◽  
Rong Wen ◽  
...  

Abstract The appearance of a complex between tyrosine-phosphorylated insulin receptor substrate 1 (IRS-1) and PI3K in a high-speed pellet fraction (HSP) is thought to be a key event in insulin action. Conversely, the disappearance of the IRS-1/PI3K complex from this fraction has been linked to insulin desensitization. The present study examines the role of 14-3-3, a specific phospho-serine binding protein, in mediating the disappearance of IRS-1 from the HSP after insulin treatment. An in vitro pull-down assay using recombinant 14-3-3 revealed that insulin enhances the association of 14-3-3 with IRS-1 in cultured adipocytes and that this is completely inhibited by wortmannin. An association of IRS-1 and 14-3-3 was also observed and was maximal after stimulation by insulin, when endogenous proteins were immunoprecipitated. Epidermal growth factor (EGF), 12-O-tetradecanoylphorbol-13-acetate, and okadaic acid, other agents that cause serine/threonine phosphorylation of IRS-1, also stimulated IRS binding to 14-3-3. The enhancement of IRS-1 binding to 14-3-3 by insulin was accompanied by movement of IRS-1 and the p85 subunit of PI3K from the HSP to the cytosol. In keeping with a key role of 14-3-3 in mediating this redistribution of IRS-1, the complexes of IRS-1 and 14-3-3 were found in the cytosol but not in the HSP of insulin-treated cells. In addition, colocalization of IRS-1 and 14-3-3 was observed in the cytoplasm after insulin treatment by confocal microscopy. Finally, the addition of a phosphorylated 14-3-3 binding peptide to an adipocyte homogenate (to remove 14-3-3 from IRS-1) increased the abundance of IRS-1/PI3K complexes in the HSP and decreased their abundance in the cytosol. These findings strongly suggest that 14-3-3 participates in the intracellular trafficking of IRS-1 by promoting the displacement of serine-phosphorylated IRS-1 from particular structures. They also suggest that 14-3-3 proteins could play an integral role in the process of insulin desensitization.


1975 ◽  
Vol 66 (3) ◽  
pp. 609-620 ◽  
Author(s):  
C Patzelt ◽  
A Singh ◽  
Y L Marchand ◽  
L Orci ◽  
B Jeanrenaud

Colchicine-binding activity of mouse liver high-speed supernate has been investigated. It has been found to be time and temperature dependent. Two binding activities with different affinities for colchicine seem to be present in this high-speed supernate, of which only the high-affinity binding site (half maximal binding at 5 x 10(-6) M colchicine) can be attributed to microtubular protein by comparison with purified tubulin. Vinblastine interacted with this binding activity by precipitating it when used at high concentrations (2 x 10(-3) M), and by stabilizing it at low concentrations (10(-5) M). Lumicolchicine was found not to compete with colchicine. The colchicine-binding activity was purified from liver and compared with that of microtubular protein from brain. The specific binding activity of the resulting preparation, its electrophoretic behavior, and the electron microscope appearance of the paracrystals obtained upon its precipitation with vinblastine permitted its identification as microtubular protein (tubulin). Electrophoretic analysis of the proteins from liver supernate that were precipitated by vinblastine indicated that this drug was not specific for liver tubulin. Preincubation of liver supernate with 5 mM EGTA resulted in a time-dependent decrease of colchicine-binding activity, which was partly reversed by the addition of Ca++. However, an in vitro formation of microtubules upon lowering the Ca++ concentration could not be detected. Finally, a method was developed enabling that portion of microtubular protein which was present as free tubulin to be measured and to be compared with the total amount of this protein in the tissue. This procedure permitted demonstration of the fact that, under normal conditions, only about 40% of the tubulin of the liver was assemled as microtubules. It is suggested that, in the liver, rapid polymerization and depolymerization of microtubules occur and may be an important facet of the functional role of the microtubular system.


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