NaYF4-based upconverting nanoparticles with optimized phosphonate coatings for chemical stability and viability of human endothelial cells

2021 ◽  
Author(s):  
Darja Lisjak ◽  
Maša Vozlič ◽  
Uliana Kostiv ◽  
Daniel Horak ◽  
Boris Majaron ◽  
...  
Keyword(s):  
Cell Culture ◽  
Endothelial Cells ◽  
Chemical Stability ◽  
Culture Medium ◽  
Cell Culture Medium ◽  
Human Endothelial Cells ◽  
Surface Quenching ◽  
Poly Ethylene ◽  
Amorphous Surface

Abstract The increasing interest in upconverting nanoparticles (UCNPs) in biodiagnostics and therapy fuels the development of biocompatible UCNPs platforms. UCNPs are typically nanocrystallites of rare-earth fluorides codoped with Yb3+ and Er3+ or Tm3+. The most studied UCNPs are based on NaYF4 but are not chemically stable in water. They dissolve significantly in the presence of phosphates. To prevent any adverse effects on the UCNPs induced by cellular phosphates, the surfaces of UCNPs must be made chemically inert and stable by suitable coatings. We studied the effect of various phosphonate coatings on chemical stability and in vitro cytotoxicity of the Yb3+,Er3+-codoped NaYF4 UCNPs in human endothelial cells obtained from cellular line Ea.hy926. Cell viability of endothelial cells was determined using the resazurin-based assay after the short-term (15 min), and long-term (24 h and 48 h) incubations with UCNPs dispersed in the cell-culture medium. The coatings were obtained from tertaphosphonic acid (EDTMP), sodium alendronate, and poly(ethylene glycol)-neridronate. Regardless of the coating conditions, 1−2 nm-thick amorphous surface layers were observed on the UCNPs with transmission electron microscopy. The upconversion fluorescence was measured in the dispersions of all synthesized UCNPs. Surface quenching in aqueous suspensions of the UCNPs was reduced by the coatings. The dissolution degree of the UCNPs was determined from the concentration of dissolved fluoride measured with ion-selective electrode after the aging of UCNPs in water, physiological buffer (i.e., phosphate-buffered saline – PBS), and cell-culture medium. The phosphonate coatings prepared at 80 °C significantly suppressed the dissolution of UCNPs in PBS, while only minor dissolution of bare and coated UCNPs was measured in water and cell-culture medium. The viability of human endothelial cells was significantly reduced when incubated with UCNPs, but it increased with the improved chemical stability of UCNPs by the phosphonate coatings with negligible cytotoxicity when coated with EDTMP at 80 °C.

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 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

Endothelial cell cystine uptake and glutathione increase with N,N-bis(2-chloroethyl)-N-nitrosourea exposure

1992 ◽  
Vol 262 (3) ◽  
pp. L301-L304 ◽  
Author(s):  
S. M. Deneke ◽  
R. A. Lawrence ◽  
S. G. Jenkinson
Keyword(s):  
Cell Culture ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Culture Medium ◽  
Cultured Cells ◽  
Potent Inhibitor ◽  
Cell Types ◽  
Cell Culture Medium ◽  
Intracellular Accumulation ◽  
Pulmonary Endothelial Cells

Glutathione (gamma-glutamylcysteinylglycine, GSH) is an important cellular antioxidant. In typical cultured cell preparations GSH synthesis is limited by the availability of intracellular cysteine. Because extracellular cystine is the chief source of intracellular cysteine in cultured cells, increasing cystine transport can result in increased intracellular GSH. Depletion of GSH or exposure to oxidants has been shown to stimulate cystine transport in bovine pulmonary endothelial cells and other cell types. BCNU [N,N-bis(2-chloroethyl)-N-nitrosourea] is a potent inhibitor of glutathione reductase (GSSG-Red). We examined the effects of BCNU on cystine uptake by bovine pulmonary artery endothelial cells (BPAEC). We hypothesized that blocking GSSG-Red could result in increased cellular uptake of cystine to replenish decreases in GSH caused by oxidation. Levels of BCNU between 0.005 and 0.05 mM added to the cell culture medium inhibited GSSG-Red at 2, 4, and 24 h after addition. BCNU treatment resulted in concentration-dependent increases in both cystine uptake and GSH levels after 24 h of exposure. The increases in uptake were specific for cystine and glutamate and were sodium independent, suggesting induction of a xc(-)-like transport system. No intracellular accumulation of GSSG was measured nor was any significant depletion of GSH noted at any time of BCNU exposure.

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.

Sign in / Sign up

Export Citation Format

Share Document