Figure - available from: Journal of Chemistry
This content is subject to copyright. Terms and conditions apply.
UV-Vis spectra of AuNPs/dextran solutions from different dextran concentrations: 0.5 (a), 1.0 (b), and 2.0% (c).
Source publication
Gold nanoparticles (AuNPs) in spherical shape with diameter of 6–35 nm stabilized by dextran were synthesized by γ -irradiation method. The AuNPs were characterized by UV-Vis spectroscopy and transmission electron microscopy. The influence of pH, Au ³⁺ concentration, and dextran concentration on the size of AuNPs was investigated. Results indicated...
Citations
... Label-free sensing probes can be achieved by stabilizing AuNPs with functional materials such as polymers. Dextran is frequently used in AuNPs synthesis due to its intrinsic chemical properties as dextran chains are rich with -OH and -COR groups giving steric and electrostatic stability to dextran-coated gold nanoparticles (dAuNPs) [32,33]. The encapsulation of dAuNPs into forms such as dextran tablet (dAuNPs-Tab), composite (dAuNPs-Comp), and powder (dAuNPs-Powder) provides a solid platform that is superior to the liquid phase due to being more thermally stable, user-friendly, easy-to-transport, and resistant to oxidation compared to the liquid phase dAuNPs [34][35][36]. ...
... Previous attempts at obtaining solid or concentrated AuNPs involved evaporation, but this method caused AuNPs aggregation due to the increased salt concentration after water evaporation [32]. Diem et al. utilized a gamma Co-60 irradiator along with spray drying, coagulation, or centrifugation to produce powdered dextran-gold nanoparticles [33]. Other attempts to synthesize highly concentrated metallic nanoparticle solutions resulted in large polydisperse particles [37]. ...
... Tablets were air-dried at room temperature for 24 h and stored in an airtight glass vial. Powder (dAuNPs-Powder) was prepared through coagulation method as described by Diem et al. [33] with Dextran-gold nanoparticles (dAuNPs) as a tunable plasmonic sensor for the detection of hypochlorite (OCl¯) in swimming pool water. Red colloidal dAuNP solution does not show any color change indicating the safe level of OCl¯ whereas the purple-blue solution shows an excess amount of OCl¯ warning the OCl¯ poisoning in the swimming pool a few modifications. ...
A tunable plasmonic sensor has been developed by varying the dextran content in the initially synthesized dextran-gold nanoparticle (dAuNPs) solution. A colloidal nanogold solution (dAuNPs-Sol) was initially prepared using dextran and gold salt in alkaline media by a one-pot green synthetic route. The dAuNPs-Sol was combined with varying amounts of dextran (ranging from 0.01 to 30.01%) to create a tunable probe, along with different solid formats, including tablet (dAuNPs-Tab), powder (dAuNPs-Powder), and composite (dAuNPs-Comp). Both the liquid and solid phase plasmonic probes were characterized using UV–vis spectroscopy, transmission electron microscopy (TEM) dynamic light scattering (DLS), and zeta potential analysis. The impact of dextran content in the dAuNP solution is studied in terms of surface charge and hydrodynamic size. The influence of operational treatments used to achieve solid dAuNPs probes is also explored. All plasmonic probes were employed to detect a broad range of OCl¯ concentrations (ranging from µM to mM) in water through aggregation followed by calculating a lower and upper limit of detection (LLoD, ULoD) of the proposed colorimetric sensors. Results indicate that the most sensitive detection is achieved with a lower dextran content (0.01%), which exhibits an LLoD of 50 µM. The dAuNPs-Sol sensor is selective and demonstrates real-world applicability, as confirmed by interference analysis and successful testing with various water samples. Additionally, it is found that a 20 × concentration of dextran-coated gold nanoparticles could be attained without any changes in the particle morphology. This concentration is achieved through a straightforward process that does not require the use of a centrifuge machine. This finding highlights the practicality and simplicity of the method, indicating its potential for scalable and cost-effective production of concentrated dAuNPs without compromising their structural integrity.
Graphical Abstract
... However, the SASD method poses challenges, including sophisticated instrumentation, high costs, and the presence of organic solvent residuals in the end product [89], which hampers further development in inhalable powder technology [20,[90][91][92]. For instance, a nanohybrid for dual-imaging consisting of strawberry-like gold-coated magnetite nanocomposites was developed by Silva et al. by SASD method. ...
... Although gold and iron NP are the only investigated contrast agent as inhalable powder via spray drying [90][91][92], this method is suitable for formulating other contrast or tracing agent into dry powder. The ability to design particle size, structure, and composition makes spray drying a promising method to produce inhalable powder for lung imaging. ...
Purpose:
The application of contrast and tracing agents is essential for lung imaging, as indicated by the wide use in recent decades and the discovery of various new contrast and tracing agents. Different aerosol production and pulmonary administration methods have been developed to improve lung imaging quality. This review details and discusses the ideal characteristics of aerosol administered via pulmonary delivery for lung imaging and the methods for the production and pulmonary administration of dry or liquid aerosol.
Methods:
We explored several databases, including PubMed, Scopus, and Google Scholar, while preparing this review to discover and obtain the abstracts, reports, review articles, and research papers related to aerosol delivery for lung imaging and the formulation and pulmonary delivery method of dry and liquid aerosol. The search terms used were "dry aerosol delivery", "liquid aerosol delivery", "MRI for lung imaging", "CT scan for lung imaging", "SPECT for lung imaging", "PET for lung imaging", "magnetic particle imaging", "dry powder inhalation", "nebuliser", and "pressurised metered-dose inhaler".
Results:
Through the literature review, we found that the critical considerations in aerosol delivery for lung imaging are appropriate lung deposition of inhaled aerosol and avoiding toxicity. The important tracing agent was also found to be Technetium-99m (99mTc), Gallium-68 (68Ga) and superparamagnetic iron oxide nanoparticle (SPION), while the essential contrast agents are gold, iodine, silver gadolinium, iron and manganese-based particles. The pulmonary delivery of such tracing and contrast agents can be performed using dry formulation (graphite ablation, spark ignition and spray dried powder) and liquid aerosol (nebulisation, pressurised metered-dose inhalation and air spray).
Conclusion:
A dual-imaging modality with the combination of different tracing or contrast agents is a future development of aerosolised micro and nanoparticles for lung imaging to improve diagnosis success.
Graphical abstract:
... A similar challenge exists in preserving nanomaterials, which tend to be in the aggregation state. Considering that the stability of solid powder is better than that of a solution, more and more research has been devoted to the preparation of powders (Hamaly et al., 2018;Tang et al., 2017;Phan Ha et al., 2017), which plays an important role in improving stability and prolonging the preservation time. 3) Nanomaterials have received much attention in recent years due to their unique optical properties , like high molar extinction coefficients and multiple color variations (Chansuvarn et al., 2015). ...
Detection of heavy metal ions has drawn significant attention in environmental and food area due to their threats to the human health and ecosystem. Colorimetry is one of the most frequently-used methods for the detection of heavy metal ions owing to its simplicity, easy operation and rapid on-site detection. The development of chromogenic materials and their sensing mechanisms are the key research direction in the area of colorimetric method. Since each chromogenic material has their unique optical and chemical properties, they have totally different colorimetric sensing mechanisms. This review focuses on the chromogenic materials and their sensing strategies for the colorimetric detection of heavy metal ions. We divide the chromogenic materials into three types, including organic materials, inorganic materials, and other materials. As for each type of chromogenic material, we discuss their detailed sensing strategies, sensing performance, and real sample applications. Moreover, current challenges and perspectives related to the colorimetry of heavy metal ions are also discussed in this review. The aim of this review is to help readers to better understand the principles of colorimetric methods for heavy metal ions and push the development of rapid detection of heavy metal ions.
... Due to these outstanding characteristics, various formats of dextran-encapsulated AuNPs have been developed including colloidal solutions, gold nanocomposites/hydrogels 37 as well as powder 38 with applications in drug delivery, 29 cell imaging, 39 wound healing, 40 and microbial susceptibility. 41 Nonetheless, dextran-capped AuNP solutions gradually aggregate to form bigger particles due to the sedimentation phenomenon of AuNPs in colloidal systems after some time. ...
... In fact, it was observed that several samples of the synthesized dextran functionalized AuNP solutions stored at normal conditions were randomly attacked by fungi. 38 In the case of powdered/gel samples, there is a serious issue of quantitative measurement of AuNPs-dSol powder/gels for a specific test every time, and hence, these samples are not suitable for direct applications and require extensive calibration procedures. ...
... Finally, the 6% AuNPs-dSol solution produced red tablets in which AuNPs remained completely dispersed and stable for an extended period of time (see section Stability and Storage of AuNPs-dTabs) because, in general, polysaccharides such as dextran, chitosan, hyaluronan, and alginate with oxygen-rich structures in hydroxyl and ether groups lead to tight binding to nanoparticles via a steric and electrostatic interaction. 38 Results from 7−10% AuNPs-dTabs were similar to 6%; however, a higher concentration of dextran was avoided to enable breaking the stabilization under mild conditions. ...
Many applications using gold nanoparticles (AuNPs) require (i) their functionalization with a biopolymer to increase their stability and (ii) their transformation into an easy-to-handle material, which provide them with specific properties. In this research, a portable tablet platform is presented based on dextran-encapsulated gold nanoparticles (AuNPs-dTab) by a ligand exchange reaction between citrate-capped gold nanoparticles (AuNPs-Cit) and dextran. These newly fabricated tablets were characterized utilizing ultraviolet-visible spectroscopy (UV-vis), Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR), transmission electron microscopy (TEM), dynamic light scattering (DLS), X-ray diffraction spectroscopy (XRD), differential scanning calorimetry (DSC), and atomic force microscopy (AFM) techniques. The results showed that dextran-capped gold nanoparticles in a tablet platform (AuNPs-dTab) were well-dispersed and highly stable for at least a year at room temperature. In addition to particle and surface characterization of AuNPs-dTab, the tablet morphology in terms of thickness, diameter, density, and opacity was also measured using 6 and 10% dextran with 2, 4 and 8 nM AuNPs-Cit. We further investigated the pH-responsive behavior of AuNPs-dTab in the presence and absence of sodium chloride. Results showed that neutral and alkaline environments were suitable to render AuNPs dispersed in a tablet, while an acidic condition controls the aggregation rate of AuNPs as confirmed by concentration-dependent aggregation phenomena. Besides the easy fabrication, these tablets were portable and low-cost (approx. 1.22 CAD per 100 tablets of a 100 μL solution of dextran-capped gold nanoparticles (AuNPs-dSol)). The biocompatible nature of dextran along with the acidic medium trigger nature of AuNPs makes our proposed tablet a potential candidate for cancer therapy due to the acidic surrounding of tumor tissues as compared to normal cells. Also, our proposed tablet approach paves the way for the fabrication of portable and easy-to-use optical sensors based on the AuNPs embedded in a natural polymeric architecture that would serve as a colorimetric recognition indicator for detecting analytes of interest.
... Capped by CM-Chitosan. The dose for radiation synthesis of AuNPs has been reported by Diem et al. [15]. These authors indicated that the required dose for completely reducing 1 mM [Au 3+ ] in Au 3+ /dextran solution by gamma-ray irradiation was 6 kGy. ...
... The results in Figure 2 and Table 1 also indicate that the optical extinction band intensities (OD values) of solutions containing 0.5, 1.0, and 1.5 mM [Au 3+ ] reached maximal values at irradiation doses of 4, 6, and 8 kGy, respectively. These results are in good agreement with those reported by Diem et al. [15] on the dose for completely reducing [Au 3+ ] into AuNPs by gamma-ray irradiation. ...
... Using other natural polymer such as dextran and hyaluronate, Hien et al. [16] and Diem et al. [15] successfully prepared AuNPs with particles below 10 nm. In the present study, TEM images and corresponding histograms of parti-cle size distributions of AuNPs in Figure 3 also showed that the AuNPs synthesized by irradiation were almost spherical. ...
Gold nanoparticles capped by carboxymethyl chitosan (AuNPs/CM-chitosan) with particle sizes of 5.2–7.3 nm were successfully synthesized by the γ-irradiation of Au3+ solutions. Their characteristics were analysed by transmission electron microscope images, powder X-ray diffraction patterns, UV-visible spectroscopy, and Fourier transform infrared spectra. The antioxidant activity of AuNP/CM-chitosan was time dependent and much higher than that of ascorbic acid at the same concentration. On the other hand, the results of tail vein injection of AuNP/CM-chitosan in mice indicated that this product was not toxic to mice and that AuNPs were mainly distributed in liver tissue, at approximately 77.5%, 6 h after injection. The hepatoprotective activity of AuNP/CM-chitosan was also tested in acetaminophen-induced hepatotoxic mice by oral administration at daily doses of 0.5–2 mg/head. The results indicated that compared to the control, supplementation with 2 mg of AuNPs/head strongly reduced the aspartate aminotransferase and alanine aminotransferase indexes in the blood of the tested mice by approximately 66.5 and 69.3%, respectively. Furthermore, the MTT (3[4,5 dimetylthiazol-2-yl]-2,5-diphenyltetrazol bromide) assay on a liver cancer cell line (HepG2) clearly confirmed strong anticancer activity on HepG2 cells treated with 0.05–0.5 mM AuNPs and the tested cells did not survive after treatment with 0.5 mM AuNPs, while the growth of the normal cell line (L929) has no significant effect at the same treated concentration of AuNPs. The AuNP/CM-chitosan in the present study was synthesized by the γ-irradiation method without using any toxic-reducing chemical and stabilized in a natural biocompatible polymer. The strong antioxidant, hepatoprotective, and anticancer effects of this product may be supported to be used in the biomedical field.
... Duy et al. [16] also informed that the SeNP size in SeNPs/oligochitosan stored at 27 • C increased more rapidly than that at 4 • C. The authors also reported that SeNPs/oligochitosan became unstable after storage for more than 28 days and turned into a black bulk mass after 42 days of storage at 25 • C. Thus, it is challenging to maintain a colloidal SeNPs solution for a long time at normal temperature and the change of SeNPs solution into powder form is a suitable way for improving the applications of this product. Thao et al. [43] prepared AuNPs/dextran by spray drying, coagulation and centrifugation methods. These authors mentioned that the change of particle size in AuNPs powders prepared by the spray drying and coagulation techniques was less than that in AuNPs made by centrifugation. ...
Selenium nanoparticles (SeNPs) with diameters from 64.8 to 110.1 nm were successfully synthesized by γ-irradiation of solutions containing Se4+ and water-soluble yeast β-glucan. The size and size distribution of SeNPs were analyzed by dynamic light scattering (DLS). Analytical X-ray diffraction (XRD) pattern results confirmed the crystal structure of the Se nanoparticles and Fourier transform infrared (FTIR) spectroscopy revealed that β-glucan could interact with SeNPs through steric (Se…O) linkages leading to a homogeneous and translucent solution state for 60 days without any precipitates. In vivo tests in cytoxan-induced immunosuppressed mice revealed that the daily supplementation of SeNPs/β-glucan at concentrations of 6 mg per kg body weight of tested mice significantly stimulated the generation of cellular immune factors (white blood cells, neutrophil, lymphocyte, B cells, CD4+ cells, CD34+ cells and natural killer cells) and humoral immune indexes (IgM, IgG, TNF-α, IFN-γ and IL-2) in peripheral blood, bone marrow and spleen of the immunosuppressed mice. The obtained results indicated that radiation-synthesized SeNPs/β-glucan may be a candidate for further evaluation as an agent for the prevention of immunosuppression in chemotherapy.
... The higher permeability for PEI-Au may occur due to the higher affinity of dextrans towards AuNPs. Some authors reported that dextrans are used as stabilizers of colloidal AuNPs solution [49]. ...
Nanocomposite multilayered membrane coatings have been widely used experimentally to enhance biomedical materials surfaces. By the selection of reliable components, such systems are functionalized to be adjusted to specific purposes. As metal nanoparticles can reduce bacterial cell adhesion, the idea of using gold and silver nanoparticles of unique antimicrobial properties within membrane structure is outstandingly interesting considering dressings facilitating wound healing. The study was aimed to explore the interface between eukaryotic cells and wound dressing materials containing various nanoelements. The proposed systems are based on polyethyleneimine and hydroxyapatite thin layers incorporating metallic nanoparticles (silver or gold). To examine the structure of designed materials scanning electron and transmission electron microscopies were applied. Moreover, Fourier-transform infrared and energy-dispersive X-ray spectroscopies were used. Additionally, water contact angles of the designed membranes and their transport properties were estimated. The functioning of human fibroblasts was examined via flow cytometry to assess the biocompatibility of developed shells in the aspect of their cytotoxicity. The results indicated that designed nanocomposite membrane scaffolds support eukaryotic cells' functioning, confirming that the elaborated systems might be recommended as wound healing materials.
... The energy consumption (E con ) of EB is related to absorbed dose (D) and radiation energy utilization efficiency (f), which are typically 0.5 for UELR-10-15S2 electro accelerator (Diem et al., 2017). E con can be calculated by Eq. (14) as follows: ...
In this study, electron-beam (EB) irradiation was employed for the degradation of tricyclazole (TC) in an aqueous solution and real pesticide industry wastewater (RPW). Acute toxicity tests revealed that TC exhibits low toxicity against Daphnia magna, with LC50 values of 52.81 mg/L, 32.68 mg/L, 24.35 mg/L and 14.56 mg/L for TC at 24 h, 48 h, 72 h and 96 h, respectively. In contrast, RPW exhibited high toxicity against D. magna, with LC50 values of 0.194%, 0.157%, 0.141% and 0.136% at 24 h, 48 h, 72 h and 96 h, respectively. Results revealed that the high-efficiency removal of TC in an aqueous solution and RPW are achieved by employing EB. Approximately 96.5% of TC in the solution was decomposed under the optimum conditions of an absorbed dose of 3.5 kGy, a pH of 7.0, and an initial TC concentration of 4 mg/L and a H2O2concentration of 4 mM with an operating cost of ∼0.92 /m³. The degradation of EB apparently followed first-order kinetics, with an R2 of ∼0.998. In real wastewater, the central composite design was employed to optimize the absorbed dose and H2O2 concentration and predict the TC and TOC removal efficiencies. Good regression coefficients (RTC2 = 0.775 and RTOC2= 0.783) of the model revealed fitted correlation between observed and predicted values. In addition, the major degradation pathways of TC were suggested by density functional theory and natural bond orbital calculations.
... Researchers have also used various biomolecules or biopolymers to stabilize GNPs and increase their biocompatibility. Chitosan, alginate, gelatin, dextran, copolymers, and biosurfactants, etc., are examples of such molecules used as stabilizing agents for gold nanoparticles [66]. Recently, Spadavecchia et al. used PEG as a stabilizing agent for GNPs, loaded them with doxorubicin, and decorated them with a polyclonal antibody to target pancreatic cancer cells [67]. ...
Cancer is one of the deadliest diseases and poses a risk to people all over the world. Surgery, chemo, and radiation therapy have been the only options available until today to combat this major problem. Chemotherapeutic drugs have been used for treatment for more than 50 years. Unfortunately, these drugs have inherent cytotoxicities and tumor cells have started inducing resistance against these drugs. Other common techniques such as surgery and radiotherapy have their own drawbacks. Therefore, such techniques are incompetent tools to alleviate the disease efficiently without any adverse effects. This scenario has inspired researchers to develop alternative techniques with enhanced therapeutic effects and minimal side effects. Such techniques include targeted therapy, liposomal therapy, hormonal therapy, and immunotherapy, etc. However, these therapies are expensive and not effective enough. Furthermore, researchers have conjugated therapeutic agents or drugs with different molecules, delivery vectors, and/or imaging modalities to combat such problems and enhance the therapeutic effect. This conjugation technique has led to the development of bioconjugation therapy, in which at least one molecule is of biological origin. These bioconjugates are the new therapeutic strategies, having prospective synergistic antitumor effects and have potency to overcome the complications being produced by chemo drugs. Herein, we provide an overview of various bioconjugates developed so far, as well as their classification, characteristics, and targeting approach for cancer. Additionally, the most popular nanostructures based on their organic or inorganic origin (metallic, magnetic, polymeric nanoparticles, dendrimers, and silica nanoparticles) characterized as nanocarriers are also discussed. Moreover, we hope that this review will provide inspiration for researchers to develop better bioconjugates as therapeutic agents.
... Interestingly, due to the presence of functional groups (e.g., eOH), some of these polymers can simultaneously act as stabilizers and reducing agents during γ-radiosynthesis [92]. Recently, Diem et al. [121] investigated the effect of dextran on the particle size distribution of γ-radiosynthesized Au NCs and found that the size of the NCs decreased by about 35% when the dextran concentration was increased from 0.5 to 2.0%. They found that the superior stabilizing performance of dextran can be attributed to the eOH and -COR functional groups in its chemical structure. ...
Over the past two decades, the radiosynthesis of metallic nanoclusters (MNCs) using γ-irradiation (γ-radiosynthesis) has presented a wealth of opportunities for the application of nanomaterials in areas such as medicine, energy, catalysis, and sensors. Unlike conventional methods, this technique provides fully reduced and highly stable MNCs that are free from by-products or impurities. γ-Radiosynthesis has thus proven to be a clean and green approach for bulk fabrication of MNCs with tunable particle sizes and morphologies. More recently, the in-situ decoration of MNCs on support materials using γ-irradiation has attracted much attention due to the synergistic effect between MNCs and the underlying support. In this review, we discuss the current state of research into the mechanisms underlying the γ-radiosynthesis of supported and unsupported mono- and bi-metallic nanoclusters and summarize the use of MNCs in catalysis, sensing, biomedicine, and energy applications.
