scholarly journals Characterisation of NiTi Orthodontic Archwires Surface after the Simulation of Mechanical Loading in CACO2-2 Cell Culture

Coatings ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 440 ◽  
Author(s):  
Nikola Lepojević ◽  
Ivana Šćepan ◽  
Branislav Glišić ◽  
Monika Jenko ◽  
Matjaž Godec ◽  
...  
Keyword(s):  
Cell Culture ◽  
Mechanical Loading ◽  
Inductively Coupled Plasma ◽  
Culture Medium ◽  
Cell Culture Medium ◽  
Nickel Ions ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Orthodontic Archwires

Nickel-titanium (NiTi) orthodontic archwires are crucial in the initial stages of orthodontic therapy when the movement of teeth and deflection of the archwire are the largest. Their great mechanical properties come with their main disadvantage—the leakage of nickel. Various in vitro studies measured nickel leakage from archwires that were only immersed in the medium with little or minimal simulation of all stress and deflection forces that affect them. This study aims to overcome that by simulating deflection forces that those archwires are exposed to inside the mouth of a patient. NiTi orthodontic archwires were immersed in CACO2-2 cell culture medium and then immediately loaded while using a simulator of multiaxial stress for 24 h. After the experiment, the surface of the NiTi orthodontic archwires were analysed while using scanning electron microscopy (SEM) and auger electron spectroscopy (AES). The observations showed significant microstructural and compositional changes within the first 51 nm thickness of the archwire surface. Furthermore, the released nickel and titanium concentrations in the CACO2-2 cell culture medium were measured while using Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). It was found out that the level of released nickel ions was 1.310 µg/L, which can be assigned as statistically significant results. These data represent the first mention of the already detectable release of Ni ions after 24 h during the simulation of mechanical loading in the CACO2-2 cell culture medium, which is important for clinical orthodontic praxis.

scholarly journals In Vitro Ion Release of Wires in Removable Orthodontic Appliances

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3402
Author(s):  
Lena Wepner ◽  
Harald Andreas Färber ◽  
Andreas Jaensch ◽  
Anna Weber ◽  
Florian Heuser ◽  
...  
Keyword(s):  
Mechanical Loading ◽  
Corrosive Medium ◽  
Inductively Coupled Plasma ◽  
Petri Dish ◽  
Orthodontic Appliances ◽  
Testing Time ◽  
Ion Release ◽  
Inductively Coupled ◽  
Corrosive Solution

Various orthodontic wire compositions and configurations are present on the market for removable appliances; however, there have still been only few studies focusing on the effect of resin color and additives such as glitter on corrosion of metallic wires under different conditions. Thus, the aim of the study was to compare concentrations of released ions (aluminium, chromium, nickel) in a corrosive medium under three different conditions: non-loaded wires, loaded wires, and non-loaded wires treated with Kukis® cleaning tablets. Six different wires made of three types of steel alloy were embedded in PMMA resin leaving one centimetre of each wire emerging from the resin to come into contact with the corrosive medium. Glitter particles were added to half of the produced test specimens. For the unloaded test series, five specimens of each group were covered in a petri dish with 50 mL of corrosive medium (pH 2.3) following EN-ISO 10271 for seven days at 37 °C. The wires for the mechanically loaded test specimens overlapped the resin by 5 cm and were clamped into a time-switched electric drive for a defined period of time before the samples were taken after a testing time of 7 days. In the third group, unloaded test specimens were transferred from their petri dishes into the prepared Kukis® solution every 24 h before being stored in the corrosive medium. Inductively coupled plasma mass spectrometry (ICP-MS) was used to quantify the specific ions in the corrosive solution. Statistical analysis showed that the mechanical loading of all wires could significantly raise the diffusion of ions into the corrosive medium. The colour of the resin did not affect the concentration of the released ions. The Kukis® cleaning tabs could not lower the corrosion of the tested metals, as some of the wires were corroded even more using the brace cleanser. Glitter-containing test specimens showed significantly higher amounts of aluminium. Mechanical loading as well as the presence of glitter particles in the resin significantly affected ion concentrations.

A Structure-Function Study of the Activity of Stem Cell Factor in Stimulating the Expansion of Cord Blood CD34+ Cells

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3501-3501
Author(s):  
Bin Shen ◽  
Wenhong Jiang ◽  
Jie Fan ◽  
Wei Dai ◽  
Xinxin Ding ◽  
...  
Keyword(s):  
Cell Culture ◽  
Monoclonal Antibody ◽  
Stem Cell ◽  
Stem Cell Factor ◽  
Culture Medium ◽  
Cell Number ◽  
Full Length ◽  
Cell Culture Medium ◽  
Cd34 Cells

Abstract Stem cell factor is one of the most important growth factors for human hematopoietic stem cells (HSC). Recombinant human stem cell factor (rhSCF) can stimulate HSC expansion and regeneration in vitro, when it is used in combination with other cytokines like Flt-3L and TPO. However, the specific structural region(s) of the rhSCF protein that are critical for its function in HSC expansion are still unknown. Few studies have addressed this problem, to date. We have recently reported the production of a novel monoclonal antibody (named 23C8) against rhSCF, and the demonstration that 23C8 could inhibit the ability of rhSCF to enhance HSC expansion. Here, we report the identification of a short polypeptide from rhSCF that contains the epitope for binding to 23C8, and, like the full-length rhSCF, is able to stimulate the expansion of umbilical cord blood (UCB)-derived CD34+ cells. Twelve short polypeptides were designed and synthesized, which cover the full length of rhSCF, with 3-5 amino acids overlaps. 23C8 was collected from hybridoma cell culture medium and further purified using protein G affinity chromatography. ELISA was used to identify the polypeptide(s) that positively react with 23C8 among all the synthesized polypeptides. In addition, the effects of the synthetic polypeptides on human HSC expansion capacity were evaluated by supplementing the cell culture medium with 100 ng/ml of a given polypeptide. Total cell number and CD34+ cell number of each group were monitored on day 6. Our novel anti-SCF monoclonal antibody (23C8) partially blocked SCF’s function in human UCB CD34+ cell expansion. Of all the polypeptides analyzed, only one, named P0, corresponding to the SCF protein sequence at residues 40 to 57, was recognized by 23C8 during ELISA. P0, like the full-length rhSCF, enhanced expansion of CD34+ cells derived from human UCB. P0 addition increased the numbers of total nucleated cells and CD34+ cells by 10.58±0.86 and 4.63±0.43 folds, respectively. For comparison, the extents of increases in cell numbers in the vehicle control group was 3.15±0.99 fold (total nucleated cells) and 1.07±0.11 fold (CD34+ cells), respectively. Residues 40-57 of hrSCF comprise a critical functional region for its ability to enhance expansion of human UCB CD34+ cells in vitro. The short P0 peptide is a potential candidate for development as a synthetic substitute for rhSCF in clinic applications. Disclosures Jiang: Biopharmagen.corp: Employment. Jiang:Biopharmagen.corp: Employment.

scholarly journals The Absorption, Distribution, and Excretion of 18 Elements of Tibetan Medicine Qishiwei Zhenzhu Pills in Rats with Cerebral Ischemia

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Yinglian Song ◽  
Ke Fu ◽  
Dewei Zhang ◽  
Min Xu ◽  
Ruixia Wu ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Inductively Coupled Plasma ◽  
Microwave Digestion ◽  
Venous Blood ◽  
Artery Occlusion ◽  
Tibetan Medicine ◽  
Inductively Coupled ◽  
Icp Ms

The aim of this study is to determine 18 elements in Tibetan medicine Qishiwei Zhenzhu pills (QSW) and their absorption, distribution, and excretion in rats with cerebral ischemia. Microwave digestion and inductively coupled plasma mass spectrometry (ICP-MS) were used to determine 18 elements of QSW in simulated gastrointestinal (GI) juice. Rats were given QSW (66.68 mg/kg) followed by middle cerebral artery occlusion (MCAO). Sham rats received saline and were not subjected to MCAO. ICP-MS was applied to determine the content of 18 elements in hepatic venous blood, abdominal aortic blood, brain, liver, kidney, hair, urine, and feces 24 h after MCAO. In vitro results showed that the extraction rate of Mn, Cu, Sr, Pb, Au, and Hg of QSW in gastric juice (1 h) was higher than that in water, and the contents of Cu, Au, Sr, and As were higher in intestinal juice (4 h) than in water. In vivo results showed that the contents of elements in the blood were quite low, and QSW increased Ni, Cr, Sr, Co, and V in artery blood and decreased V in venous blood. Elements in the tissues were also low, and QSW increased brain Li but decreased Cr and Cd; QSW increased kidney Ag and Cs and liver Mn but decreased liver Ni. QSW increased urinary excretion of Li, Sr, Hg, Cs, and V; QSW increased Hg content in hair but decreased Ni. Stool is the main excretion pathway of the elements in QSW, with Ba, Mn, Sr, Cd, V, Cu, Cs, Li, Pb, Ag, Hg, Cr, As, and Co the highest. In summary, this study examined the distribution of 18 elements in QSW-treated MCAO rats. The accumulation of these elements in blood and tissues was extremely low, and the majority was excreted in feces within 24 h, highlighting the importance of the gut-microbiota-brain axis in QSW-mediated brain protection.

scholarly journals Exposure Setup and Dosimetry for a Study on Effects of Mobile Communication Signals on Human Hematopoietic Stem Cells in vitro

2017 ◽  
Vol 15 ◽  
pp. 207-213
Author(s):  
Martina Rohland ◽  
Kai Baaske ◽  
Katharina Gläser ◽  
Henning Hintzsche ◽  
Helga Stopper ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cell Culture ◽  
Hematopoietic Stem Cells ◽  
Mobile Communication ◽  
Culture Medium ◽  
Cell Culture Medium ◽  
Scattering Parameter ◽  
Hematopoietic Stem ◽  
Communication Signals

Abstract. In this paper we describe the design of an exposure setup used to study possible non-thermal effects due to the exposure of human hematopoietic stem cells to GSM, UMTS and LTE mobile communication signals. The experiments are performed under fully blinded conditions in a TEM waveguide located inside an incubator to achieve defined environmental conditions as required for the living cells. Chamber slides containing the cells in culture medium are placed on the septum of the waveguide. The environmental and exposure parameters such as signal power, temperatures, relative humidity and CO2 content of the surrounding atmosphere are monitored permanently during the exposure experiment. The power of the exposure signals required to achieve specific absorption rates of 0.5, 1, 2 and 4 W kg−1 are determined by numerical calculation of the field distribution inside the cell culture medium at 900 MHz (GSM), 1950 MHz (UMTS) and 2535 MHz (LTE). The dosimetry is verified both with scattering parameter measurements on the waveguide with and without containers filled with cell culture medium and with temperature measurements with non-metallic probes in separate heating experiments.

scholarly journals COMPOSITION AND FUNCTIONS OF EXTRACELLULAR PROTEINS IN LEAF APOPLAST AND IN VITRO CELL CULTURE MEDIUM OF TARTARY BUCKWHEAT

2020 ◽  
Author(s):  
Н.И. Румянцева ◽  
A.И. Валиева ◽  
A.Н. Акулов ◽  
A.В. Лайков ◽  
Ю.A. Костюкова ◽  
...  
Keyword(s):  
Cell Culture ◽  
Culture Medium ◽  
Extracellular Proteins ◽  
Tartary Buckwheat ◽  
Cell Culture Medium ◽  
In Vitro Cell Culture ◽  
Leaf Apoplast

IN VITRO OSTEO-INDUCTIVE CHARACTERIZATION OF NANO-GRADE PEARL POWDERS

2011 ◽  
Vol 23 (02) ◽  
pp. 135-140
Author(s):  
Mei-Ju Hou ◽  
Chi-Jen Shih
Keyword(s):  
Inductively Coupled Plasma ◽  
Body Fluid ◽  
X Ray Diffraction ◽  
X Ray ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Hydroxyl Apatite ◽  
Inductive Behavior

The main objective of this study is to characterize the in vitro osteo inductive behavior of pearl nano crystallites. The results obtained from X-ray diffraction, Fourier transform infrared (FTIR) spectra, and inductively coupled plasma mass (ICP-MS) analysis demonstrate that the pearls can induce the formation of a hydroxyl apatite (HA) layer on their surface in simulated body fluid (SBF), even after only short soaking periods. Further, MC3T3-E1 cells can easily attach and spread on the pearl powders after 1 h of cultivation.

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