scholarly journals Silver Nanoparticles Agglomerate Intracellularly Depending on the Stabilizing Agent: Implications for Nanomedicine Efficacy

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1953
Author(s):  
Marina R. Mulenos ◽  
Henry Lujan ◽  
Lauren R. Pitts ◽  
Christie M. Sayes

Engineered nanoparticles are utilized as drug delivery carriers in modern medicine due to their high surface area and tailorable surface functionality. After in vivo administration, nanoparticles distribute and interact with biomolecules, such as polar proteins in serum, lipid membranes in cells, and high ionic conditions during digestion. Electrostatic forces and steric hindrances in a nanoparticle population are disturbed and particles agglomerate in biological fluids. Little is known about the stability of nanoparticles in relation to particle surface charge. Here, we compared three different surface-stabilized silver nanoparticles (50 nm) for intracellular agglomeration in human hepatocellular carcinoma cells (HepG2). Nanoparticles stabilized with branched polyethyleneimine conferred a positive surface charge, particles stabilized with lipoic acid conferred a negative surface charge, and particles stabilized with polyethylene glycol conferred a neutral surface charge. Particles were incubated in fetal bovine serum, simulated lung surfactant fluid, and simulated stomach digestion fluid. Each nanoparticle system was characterized via microscopic (transmission electron, fluorescence, and enhanced darkfield) and spectroscopic (hyperspectral, dynamic light scattering, and ultraviolet-visible absorption) techniques. Results showed that nanoparticle transformation included cellular internalization, agglomeration, and degradation and that these changes were dependent upon surface charge and incubation matrix. Hyperspectral analyses showed that positively charged silver nanoparticles red-shifted in spectral analysis after transformations, whereas negatively charged silver nanoparticles blue-shifted. Neutrally charged silver nanoparticles did not demonstrate significant spectral shifts. Spectral shifting indicates de-stabilization in particle suspension, which directly affects agglomeration intracellularly. These characteristics are translatable to critical quality attributes and can be exploited when developing nano-carriers for nanomedicine.

Marine Drugs ◽  
2020 ◽  
Vol 18 (7) ◽  
pp. 356 ◽  
Author(s):  
Hanaa Ali Hussein ◽  
Mohd Azmuddin Abdullah

Cancer is the main cause of death worldwide, so the discovery of new and effective therapeutic agents must be urgently addressed. Diatoms are rich in minerals and secondary metabolites such as saturated and unsaturated fatty acids, esters, acyl lipids, sterols, proteins, and flavonoids. These bioactive compounds have been reported as potent anti-cancer, anti-oxidant and anti-bacterial agents. Diatoms are unicellular photosynthetic organisms, which are important in the biogeochemical circulation of silica, nitrogen, and carbon, attributable to their short growth-cycle and high yield. The biosilica of diatoms is potentially effective as a carrier for targeted drug delivery in cancer therapy due to its high surface area, nano-porosity, bio-compatibility, and bio-degradability. In vivo studies have shown no significant symptoms of tissue damage in animal models, suggesting the suitability of a diatoms-based system as a safe nanocarrier in nano-medicine applications. This review presents an overview of diatoms’ microalgae possessing anti-cancer activities and the potential role of the diatoms and biosilica in the delivery of anticancer drugs. Diatoms-based antibodies and vitamin B12 as drug carriers are also elaborated.


2021 ◽  
Vol 21 (5) ◽  
pp. 2705-2741
Author(s):  
Maria Monteserín ◽  
Silvia Larumbe ◽  
Alejandro V. Martínez ◽  
Saioa Burgui ◽  
L. Francisco Martín

The unique properties of magnetic nanoparticles have led them to be considered materials with significant potential in the biomedical field. Nanometric size, high surface-area ratio, ability to function at molecular level, exceptional magnetic and physicochemical properties, and more importantly, the relatively easy tailoring of all these properties to the specific requirements of the different biomedical applications, are some of the key factors of their success. In this paper, we will provide an overview of the state of the art of different aspects of magnetic nanoparticles, specially focusing on their use in biomedicine. We will explore their magnetic properties, synthetic methods and surface modifications, as well as their most significative physicochemical properties and their impact on the in vivo behaviour of these particles. Furthermore, we will provide a background on different applications of magnetic nanoparticles in biomedicine, such as magnetic drug targeting, magnetic hyperthermia, imaging contrast agents or theranostics. Besides, current limitations and challenges of these materials, as well as their future prospects in the biomedical field will be discussed.


RSC Advances ◽  
2020 ◽  
Vol 10 (61) ◽  
pp. 37374-37381
Author(s):  
Santhosh S. Nair ◽  
Jianhong Chen ◽  
Adam Slabon ◽  
Aji P. Mathew

Cellulose nanocrystals (CNCs) are promising building blocks for water purification due to their high surface area, tuneability of surface charge and grafting of surface groups depending on the pollutants.


2015 ◽  
Vol 128 ◽  
pp. 347-356 ◽  
Author(s):  
Kavitha Kandiah ◽  
Rajendran Venkatachalam ◽  
Chunyan Wang ◽  
Suresh Valiyaveettil ◽  
Kumaresan Ganesan

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Hisao Haniu ◽  
Naoto Saito ◽  
Yoshikazu Matsuda ◽  
Tamotsu Tsukahara ◽  
Yuki Usui ◽  
...  

Carbon nanotubes (CNTs) are attracting interest in various fields of science because they possess a high surface area-to-volume ratio and excellent electronic, mechanical, and thermal properties. Various medical applications of CNTs are expected, and the properties of CNTs have been greatly improved for use in biomaterials. However, the safety of CNTs remains unclear, which impedes their medical application. Our group is evaluating the biological responses of multiwall CNTs (MWCNTs)in vivoandin vitrofor the promotion of tissue regeneration as safe scaffold materials. We recently showed that intracellular accumulation is important for the cytotoxicity of CNTs, and we reported the active physiological functions CNTs in cells. In this review, we describe the effects of CNTsin vivoandin vitroobserved by our group from the standpoint of tissue engineering, and we introduce the findings of other research groups.


2018 ◽  
Vol 2 ◽  
pp. 13 ◽  
Author(s):  
Frans J. Walther ◽  
Monik Gupta ◽  
Larry M. Gordon ◽  
Alan J. Waring

Background: Animal-derived surfactants containing surfactant proteins B (SP-B) and C (SP-C) are used to treat respiratory distress syndrome (RDS) in preterm infants. SP-B (79 residues) plays a pivotal role in lung function and the design of synthetic lung surfactant. Super Mini-B (SMB), a 41-residue peptide based on the N- and C-domains of SP-B covalently joined with a turn and two disulfides, folds as an α-helix hairpin mimicking the properties of these domains in SP-B. Here, we studied ‘B-YL’, a 41-residue SMB variant that has its four cysteine and two methionine residues replaced by tyrosine and leucine, respectively, to test whether these hydrophobic substitutions produce a surface-active, α-helix hairpin. Methods: Structure and function of B-YL and SMB in surfactant lipids were compared with CD and FTIR spectroscopy, and surface activity with captive bubble surfactometry and in lavaged, surfactant-deficient adult rabbits. Results: CD and FTIR spectroscopy of B-YL in surfactant lipids showed secondary structures compatible with peptide folding as an α-helix hairpin, similar to SMB in lipids. B-YL in surfactant lipids demonstrated excellent in vitro surface activity and good oxygenation and dynamic compliance in lavaged, surfactant-deficient adult rabbits, suggesting that the four tyrosine substitutions are an effective replacement for the disulfide-reinforced helix-turn of SMB. Here, the B-YL fold may be stabilized by a core of clustered tyrosines linking the N- and C-helices through non-covalent interactions involving aromatic rings. Conclusions: ‘Sulfur-free’ B-YL forms an amphipathic helix-hairpin in surfactant liposomes with high surface activity and is functionally similar to SMB and native SP-B. The removal of the cysteines makes B-YL more feasible to scale up production for clinical application. B-YL’s possible resistance against free oxygen radical damage to methionines by substitutions with leucine provides an extra edge over SMB in the treatment of respiratory failure in preterm infants with RDS.


2019 ◽  
Vol 48 (8) ◽  
pp. 2692-2700 ◽  
Author(s):  
Hui-Tao Fan ◽  
Xue-Guo Liu ◽  
Xiao-Jing Xing ◽  
Bo Li ◽  
Kun Wang ◽  
...  

An Ag–OMS-C nanocomposite with a high surface area was proposed, and its potential application for catalytic activity was highlighted.


Author(s):  
Fernanda Pilaquinga ◽  
Jeroni Morey ◽  
Miguel Vivas-Rodríguez ◽  
Gabriela Yánez-Jácome ◽  
Lenys Fernández ◽  
...  

: Mercury (Hg) contamination is a problem that currently affects not only the environment but also human health. Various types of commercial adsorbents have been proposed for its removal. Silver is a noble element that can chemically adsorb mercury, forming amalgams. However, its use as an adsorbent presents the following disadvantages: rapid surface saturation and high cost. These limitations can easily be overcome using silver nanoparticles (AgNPs). With a size of less than 100 nm, their reactivity, their high surface area, and a minimal amount of metallic precursor, they are ideal candidates for mercury removal. This study presents a compendium of the use of conventional mercury adsorbents and the use of AgNPs for their colorimetric detection and removal in different matrices, in both the aqueous and gas phases of Hg0 and Hg2+ . In addition, the number of patents available in each case is analyzed. AgNPs as colorimetric sensors allow for quick detection of mercury in-situ. Additionally, the adsorption systems formed with AgNPs, allow for the obtaining of stable and chemically inert complexes, facilitating their recycling. It is concluded that the use of AgNPs is particularly efficient for the detection and removal of mercury, presenting a removal percentage of over 90%. As a result of the patents analyzed, its use is perfectly applicable at an industrial level.


2021 ◽  
Vol 21 (12) ◽  
pp. 5979-5986
Author(s):  
Gui Bing Hong ◽  
Yi Hua Luo ◽  
Kai Jen Chuang ◽  
Chih Ming Ma

Noble metal nanoparticles have special properties in optical, electronic, and physical chemistry due to their high surface area and volume. With the development of electronic printing technology, inkjet printing has gradually replaced traditional spin coating and blade coating, since it leads to more material savings and a faster batch production, and the pattern can be easily designed by a computer. In this study, Ag nanoparticles were prepared by a chemical reduction method. Non-toxic, environment-friendly agents were selected to fabricate a single-shape, uniform-size, crystal-form, and monodisperse product. The effects of the reducing agent ratio and the stabilizer ratio on the size, shape, and stability of the nanoparticles are discussed. The silver nanoparticles were characterized by an ultraviolet-visible spectrophotometer (UV-vis) and a transmission electron microscope (TEM). In addition, in order to prepare conductive ink that can stably disperse for a long time and that can be applied to inkjet printing on a PET flexible substrate at a lower sintering temperature, a sintering agent and a commercial surfactant were added. The experimental results show that the best addition ratio of the precursor to the reducing agent and the stabilizer is 1:6:1. The conductive silver ink was printed and treated by a70 mM NaCl solution, and the electric resistivity was 5.17×10−4 Ω· cm.


2017 ◽  
Vol 01 (04) ◽  
pp. 1750011 ◽  
Author(s):  
Shounak Roy ◽  
Amit Jaiswal

Graphene and graphene-based nanomaterials such as graphene oxide (GO), reduced graphene oxide (rGO) and graphene quantum dots (GQDs) have gained a lot of attention from diverse scientific fields for applications in sensing, catalysis, nanoelectronics, material engineering, energy storage and biomedicine due to its unique structural, optical, electrical and mechanical properties. Graphene-based nanomaterials emerge as a novel class of nanomedicine for cancer therapy for several reasons. Firstly, its structural properties like high surface area and aromaticity enables easy loading of hydrophobic drugs. Secondly, presence of oxygen containing functional groups improve its physiological stability and also act as site for biofunctionalization. Thirdly, its optical absorption in the NIR region enable them to act as photoagents for photothermal and photodynamic therapies of cancer, both in vitro and in vivo. Finally, its intrinsic fluorescence property helps in bioimaging of cancer cells. Overall, graphene-based nanomaterials can act as agents for developing multifunctional theranostic platforms for carrying out more efficient detection and treatment of cancers. This review provides a detailed summary of the different applications of graphene-based nanomaterials in drug delivery, nucleic acid delivery, phototherapy, bioimaging and theranostics.


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