The Synthesis of the Folate Acid Quantum Dots and Its Endocytosis in the Hepatoma Cells Mediated by the Folate Receptor

2019 ◽  
Vol 9 (6) ◽  
pp. 770-777
Author(s):  
Xiao-Li Zhu ◽  
Jing-Cheng Tang ◽  
Bing-Jiu Xu
Keyword(s):  
Quantum Dots ◽  
Folic Acid ◽  
Hepg2 Cells ◽  
Folate Receptor ◽  
Synthetic Medium ◽  
Water Soluble ◽  
Mercaptoacetic Acid ◽  
Green Method ◽  
Cds Qds ◽  
Hepg2 Cell Lines

Objectives: To synthesize folate acid conjugated quantum dots (QDs) by a simple and green method and explore endocytosis of the QD-folic acid conjugates (FA-QDs) into hepG2 cells. Methods: CdS QDs were prepared using stearic acid as synthetic medium, and were conjugated with mercaptoacetic acid (MAA) to be water-soluble. Then folic acid moiety was coupled to the surface of the QDs using EDC (1-ethyl-3-(3-dimethylamino propyl)carbodiimide) as a coupling agent. The CdS QDs and FA-QDs were characterized by X-ray spectroscopy (XRD), transmission electron microscopy (TEM), spectro fluorimetry and infrared spectroscopy. Endocytosis of the FA-QDs into hepG2 cells was observed by confocal microscopy and TEM. Results: TEM shows that the CdS QDs and FA-QDs were spherical in shape and had a diameter of 10 nm. Fluorescence spectrum of the QDs also shows their narrow size distribution. Confocal microscopic and TEM results show that FA-QDs were successfully internalized into the hepG2 cells. In addition, confocal results show that when the cells were first be saturated with excess free FA, the endocytosis of the FA-QDs became less, and CdS QDs that were not conjugated with FA were not able to be internalized into the hepG2 cells. Conclusions: The FA-QDs can be synthesized by a simple and green method and be used to successfully target tumor cells: hepG2 cell lines, which was probably mediated by the FA receptor.

scholarly journals Cell Imaging Using Two-Photon Excited CdS Fluorescent Quantum Dots Working within the Biological Window

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 369 ◽  
Author(s):  
Nannan Zhang ◽  
Xiao Liu ◽  
Zhongchao Wei ◽  
Haiying Liu ◽  
Jie Peng ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Hepg2 Cells ◽  
Fluorescence Emission ◽  
Image Resolution ◽  
Water Soluble ◽  
First Principles Calculation ◽  
Control Group ◽  
Excitation Light ◽  
Two Photon ◽  
Cds Qds

In recent years, two-photon excited semiconductor quantum dots (QDs) have been the subject of intense investigation due to their long excitation wavelength which helps to achieve deeper penetration and higher image resolution in optical bioimaging. In this paper, water-soluble CdS QDs were synthesized using a hydrothermal method and applied to human liver hepatocellular carcinoma (HepG2) cells. The first-principles calculation suggested that the S-rich defected structure contributes to a narrower band gap compared to the pristine structure. The resulting fluorescence wavelength was significantly red shifted, which was attributed to the deep defect states emission. The large Stokes shifts (> 200 nm) of the QDs can eliminate the possible cross-talk between the excitation light and the emission light. Two-photon induced red fluorescence emission can avoid overlapping with the autofluorescence emission of biological samples. The uptake and cell viability measurements of the HepG2 cells showed a good biocompatibility and a low toxicity of CdS QDs. Two-photon excited scanning microscopy images revealed that the HepG2 cells incubated with CdS QDs emitted bright red upconversion fluorescence and the fluorescence brightness was 38.2 times of that of the control group. These results support CdS QDs as a good candidate for application in cellular imaging.

scholarly journals Fluorescence modulation of cadmium sulfide quantum dots by azobenzene photochromic switches

2016 ◽  
Vol 472 (2186) ◽  
pp. 20150692 ◽  
Author(s):  
Hina Javed ◽  
Kalsoom Fatima ◽  
Zareen Akhter ◽  
Muhammad Arif Nadeem ◽  
Muhammad Siddiq ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Cadmium Sulfide ◽  
Mercaptoacetic Acid ◽  
X Ray Diffraction ◽  
Photochromic Compounds ◽  
Lowest Unoccupied Molecular Orbital ◽  
Modified Surface ◽  
Fluorescence Modulation ◽  
Cds Qds ◽  
Surface Modified

We have investigated the attachment of azobenzene photochromic switches on the modified surface of cadmium sulfide (CdS) quantum dots (QDs). The modification of CdS QDs is done by varying the concentration of the capping agent (mercaptoacetic acid) and NH 3 in order to control the size of the QDs. The X-ray diffraction studies revealed that the crystallite size of CdS QDs ranged from 6 to 10 nm. The azobenzene photochromic derivatives bis(4-hydroxybenzene-1-azo)4,4′(1,1′ diphenylmethane) (I) and 4,4′-diazenyldibenzoic acid (II) were synthesized and attached with surface-modified CdS QDs to make fluorophore–photochrome CdS-(I) and CdS-(II) dyad assemblies. Upon UV irradiation, the photochromic compounds (I) and (II) undergo a reversible trans – cis isomerization. The photo-induced trans – cis transformation helps to transfer photo-excited electrons from the conduction band of the CdS QDs to the lowest unoccupied molecular orbital of cis isomer of photochromic compounds (I) and (II). As a result, the fluorescence of CdS-(I) and CdS-(II) dyads is suppressed approximately five times compared to bare CdS QDs. The fluorescence modulation in such systems could help to design luminescent probes for bioimaging applications.

Detection of ascorbic acid and folic acid based on water-soluble CuInS2 quantum dots

The Analyst ◽  
2012 ◽  
Vol 137 (19) ◽  
pp. 4598 ◽  
Author(s):  
Siyu Liu ◽  
Junjie Hu ◽  
Xingguang Su
Keyword(s):  
Quantum Dots ◽  
Ascorbic Acid ◽  
Folic Acid ◽  
Water Soluble ◽  
Cuins2 Quantum Dots

Selective detection of folic acid in the midst of other biomolecules using water-soluble AgInS2 quantum dots

2019 ◽  
Vol 9 (4) ◽  
pp. 1306-1310 ◽  
Author(s):  
Bambesiwe M.M. May ◽  
Sundararajan Parani ◽  
Jose Varghese Rajendran ◽  
Oluwatobi S. Oluwafemi
Keyword(s):  
Quantum Dots ◽  
Folic Acid ◽  
Water Soluble ◽  
Selective Detection ◽  
Image Position

Abstract

Fabrication and multifunctional properties of ultrasmall water-soluble tungsten oxide quantum dots

2016 ◽  
Vol 52 (61) ◽  
pp. 9534-9537 ◽  
Author(s):  
Huaping Peng ◽  
Pan Liu ◽  
Danwei Lin ◽  
Yani Deng ◽  
Yun Lei ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Tungsten Oxide ◽  
Water Soluble ◽  
Green Method ◽  
Multifunctional Properties

Novel ultrasmall water-soluble tungsten oxide quantum dots with multifunctional properties have been successfully developed by a facile and green method.

Folate Receptor Saturation, Recycling, and Release Kinetics in Activated Macrophages

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4655-4655
Author(s):  
Bindu Varghese ◽  
Erina Vlashi ◽  
Philip S. Low
Keyword(s):  
Folic Acid ◽  
Folate Receptor ◽  
Release Kinetics ◽  
Water Soluble ◽  
Imaging Agents ◽  
Activated Macrophages ◽  
Binding Characteristics ◽  
Folate Conjugate ◽  
Made In

Abstract Activated macrophages over-express a receptor for the vitamin, folic acid. Conjugation of folic acid to low molecular weight drugs, genes, liposomes, nanoparticles, and imaging agents does not significantly compromise the vitamin’s affinity for its receptor, thus facilitating both therapeutic and imaging agents to be targeted as folate conjugates to activated macrophages. In these studies the in vivo kinetics and binding characteristics of the folate receptor on macrophages has been characterized with the objective of optimizing targeted drug delivery. Our results show that saturation of the receptor in inflamed tissues can be reached at a dose of 100 nmol/kg. Furthermore, the rapid recycling characteristics of the receptor (every 10–20 minutes) suggests that frequent dosing will allow for maximal uptake of folate conjugates by activated macrophages accumulated in inflamed tissues. Finally, the short circulation half-life (30 minutes) of the water-soluble folate conjugate used in this study minimizes the possibility of nonspecific uptake by receptor-negative tissues. The kinetic observations made in this study can be utilized to optimize the therapeutic efficacy and imaging agent delivery of folate conjugates to activated macrophages in vivo.

scholarly journals Sensitive Determination of Cetirizine Using CdS Quantum dots as Oxidase Mimic-mediated Chemiluminescence of Sulfite

2016 ◽  
Vol 5 (7) ◽  
pp. 59-62 ◽  
Author(s):  
Reza Hoseinpour Kouhestany ◽  
Seyed Naser Azizi ◽  
Parmis Shakeri ◽  
Shaghyegh Rahmani
Keyword(s):  
Quantum Dots ◽  
Limit Of Detection ◽  
Ultra Violet ◽  
Cost Effective ◽  
Pharmaceutical Journal ◽  
Water Soluble ◽  
Cds Quantum Dots ◽  
Study Results ◽  
Cds Qds

A new chemiluminescence (CL) method using cadmium sulfide quantum dots (QDs) as sensitizers is proposed for the chemiluminometric determination of cetirizine pharmaceutical formulation. CdS QDs were synthesized by using water soluble route. The nanoparticles were structurally and optically characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Ultra Violet-Visible (UV–Vis) absorption spectroscopy and scanning electron microscopy (SEM). In this study results shows that CdS quantum dots are enhancers of the weak CL emission. Trace amounts of cetirizine improved the sensitize effect of CdS quantum dots yielding a significant chemiluminescence enhancement of the Ce(IV)–SO32?–CdS QDs system. So, a new CL analysis system was selected for the determination of cetirizine. There is a good linear relationship between the relative chemiluminescence intensity and the concentration of cetirizine in the range of 1×10?9– 1×10?6 molL?1 with a correlation coefficient (R2) of 0.9963 at the optimum conditions. The limit of detection (LOD) of this system was found to be 5×10?11 M. This method is simple, sensitive and cost effective, and also is accommodating for pharmaceutical applications.Kouhestany et al., International Current Pharmaceutical Journal, June 2016, 5(7): 59-62

scholarly journals Data on HepG2 cells changes following exposure to cadmium sulphide quantum dots (CdS QDs)

Data in Brief ◽  
2017 ◽  
Vol 11 ◽  
pp. 72-97 ◽  
Author(s):  
Laura Paesano ◽  
Alessio Perotti ◽  
Annamaria Buschini ◽  
Cecilia Carubbi ◽  
Marta Marmiroli ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Hepg2 Cells ◽  
Cadmium Sulphide ◽  
Cds Qds

scholarly journals CdTe Quantum Dots Modified with Cysteamine: A New Efficient Nanosensor for the Determination of Folic Acid

Sensors ◽  
2019 ◽  
Vol 19 (20) ◽  
pp. 4548 ◽  
Author(s):  
Doris E. Ramírez-Herrera ◽  
Ana Patricia Reyes-Cruzaley ◽  
Giselle Dominguez ◽  
Francisco Paraguay-Delgado ◽  
Antonio Tirado-Guízar ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Folic Acid ◽  
Fluorescence Quenching ◽  
Low Cost ◽  
Water Soluble ◽  
Cdte Quantum Dots ◽  
Photoluminescence Intensity ◽  
Beverage Samples ◽  
Cdte Qds

In this paper, we report the synthesis, characterization, and application of a new fluorescent nanosensor based on water-soluble CdTe quantum dots (QDs) coated with cysteamine (CA) for the determination of folic acid (FA). CdTe/CA QDs were characterized by high-resolution transmission electron microscopy, the zeta potential, and Fourier-transform infrared (FT-IR), UV-visible, and fluorescence spectroscopy. CdTe QDs coated with mercaptopropionic acid (MPA) and glutathione (GSH) were prepared for comparison purposes. The effect of FA on the photoluminescence intensity of the three thiol-capped QDs at pH 8 was studied. Only CdTe/CA QDs showed a notable fluorescence quenching in the presence of FA. Then, a nanosensor based on the fluorescence quenching of the CdTe QDs at pH 8 was explored. Under optimum conditions, the calibration curve showed a linear fluorescence quenching response in a concentration range of FA from 0.16 to 16.4 μM (R2 = 0.9944), with a detection limit of 0.048 μM. A probable mechanism of fluorescence quenching was proposed. The nanosensor showed good selectivity over other possible interferences. This method has been applied for FA quantification in orange beverage samples with excellent results (recoveries from 98.3 to 103.9%). The good selectivity, sensitivity, low cost, and rapidity make CdTe /CA QDs a suitable nanosensor for FA determination.

Sign in / Sign up

Export Citation Format

Share Document