Synthetic preparations and atomic scale engineering of silver nanoparticles for biomedical applications

Nanoscale ◽  
2021 ◽  
Author(s):  
Ajinkya Girish Nene ◽  
Massimiliano Galluzzi ◽  
Hongrong Luo ◽  
Prakash Somani ◽  
Seeram Ramakrishna ◽  
...  

Owning peculiar oxidative effect, silver cations (Ag+) are well-known for antimicrobial properties and explored as therapeutic agents for biomedical applications. Size control with improved dispersion and stability are the key factors...

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 380 ◽  
Author(s):  
Diana Rafael ◽  
Fernanda Andrade ◽  
Francesc Martinez-Trucharte ◽  
Jana Basas ◽  
Joaquín Seras-Franzoso ◽  
...  

Hydrogels (HG) have recognized benefits as drug delivery platforms for biomedical applications. Their high sensitivity to sterilization processes is however one of the greatest challenges regarding their clinical translation. Concerning infection diseases, prevention of post-operatory related infections is crucial to ensure appropriate patient recovery and good clinical outcomes. Silver nanoparticles (AgNPs) have shown good antimicrobial properties but sustained release at the right place is required. Thus, we produced and characterized thermo-sensitive HG based on Pluronic® F127 loaded with AgNPs (HG-AgNPs) and their integrity and functionality after sterilization by dry-heat and autoclave methods were carefully assessed. The quality attributes of HG-AgNPs were seriously affected by dry-heat methods but not by autoclaving methods, which allowed to ensure the required sterility. Also, direct sterilization of the final HG-AgNPs product proved more effective than of the raw material, allowing simpler production procedures in non-sterile conditions. The mechanical properties were assessed in post mortem rat models and the HG-AgNPs were tested for its antimicrobial properties in vitro using extremely drug-resistant (XDR) clinical strains. The produced HG-AgNPs prove to be versatile, easy produced and cost-effective products, with activity against XDR strains and an adequate gelation time and spreadability features and optimal for in situ biomedical applications.


2021 ◽  
Author(s):  
Nadezhda Samoilova ◽  
Maria Krayukhina ◽  
Alexander Naumkin ◽  
Nelya Anuchina ◽  
Dmitry Popov

The combined composites containing silver nanoparticles and silver cations were proposed. Water-soluble complexes of silver nanoparticles (AgNPs) stabilized by copolymers of maleic acid with ethylene or N-vinylpyrrolidone were doped with...


2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
I. DeAlba-Montero ◽  
Claudio A. Ruiz-Torres ◽  
Diana P. Portales-Pérez ◽  
Fidel Martínez-Gutierrez ◽  
Félix Echeverría ◽  
...  

Silver nanoparticles (AgNPs) have been widely employed or incorporated into different materials in biological application, due to their antibacterial properties. Therefore, antimicrobial capacity and cytotoxicity have been highly studied. However, most of these reports do not consider the possible corrosion of the nanomaterials during their exposure to atmospheric conditions since AgNPs undergo a transformation when they come in contact with a particular environment. Derived from this, the functionality and properties of the nanoparticles could decrease noticeably. The most common silver corrosion process occurs by the interaction of AgNPs with sulfur species (H2S) present in the atmospheric air, forming a corrosion layer of silver sulfide around the AgNPs, thus inhibiting the release of the ions responsible for the antimicrobial activity. In this work, AgNPs were synthesized using two different methods: one of them was based on a plant extract (Brickellia cavanillesii), and the other one is the well-known method using sodium borohydride (NaBH4). Chemical stability, corrosion, antibacterial activity, and toxic activity were evaluated for both sets of prepared samples, before and after exposition to atmospheric air for three months. The structural characterization of the samples, in terms of crystallinity, chemical composition, and morphology, evidenced the formation of link structures with nanobridges of Ag2S for non- “green” AgNPs after the air exposition and the intact preservation of silver core for the “green” sample. The antibacterial activity showed a clear improvement in the antimicrobial properties of silver in relation to the “green” functionalization, particle size control, and size reduction, as well as the preservation of the properties after air exposition by the effective “green” protection. The cytotoxicity effect of the different AgNPs against mononuclear cells showed a notable increment in the cell viability by the “green” functionalization.


2012 ◽  
Vol 18 (S5) ◽  
pp. 55-56
Author(s):  
A. P. Zaderenko ◽  
P. M. Castillo ◽  
M. de la Mata ◽  
M .J. Sayagués ◽  
J. A. Sánchez

There is a growing interest in nanoparticles as carriers of chemotherapeutic agents in order to improve their administration and minimize their side effects. Despite the fact that silver nanoparticles can be conjugated to therapeutic agents, offering additionally advantages due their unique and tunable optical properties, few examples have been described yet.


2019 ◽  
Vol 26 (35) ◽  
pp. 6399-6411 ◽  
Author(s):  
Cláudia Nunes ◽  
Manuel A. Coimbra

Marine environments have a high quantity and diversity of sulfated polysaccharides. In coastal regions brown algae are the most abundant biomass producers and their cell walls have fucosecontaining sulfated polysaccharides (FCSP), known as fucans and/or fucoidans. These sulfated compounds have been widely researched for their biomedical properties, namely the immunomodulatory, haemostasis, pathogen inhibition, anti-inflammatory capacity, and antitumoral. These activities are probably due to their ability to mimic the carbohydrate moieties of mammalian glycosaminoglycans. Therefore, the FCSP are interesting compounds for application in health-related subjects, mainly for developing scaffolds for delivery systems or tissue regeneration. FCSP showed potential for these applications also due to their ability to form stable 3D structures with other polymers able to entrap therapeutic agents or cell and growth factors, besides their biocompatibility and biodegradability. However, for the clinical use of these biopolymers well-defined reproducible molecules are required in order to accurately establish relationships between structural features and human health applications.


Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 317
Author(s):  
HanGoo Kang ◽  
Jinwon Seo ◽  
Eun-Jeong Yang ◽  
In-Hong Choi

Silver nanoparticles (AgNPs) are widely used in various fields because of their antimicrobial properties. However, many studies have reported that AgNPs can be harmful to both microorganisms and humans. Reactive oxygen species (ROS) are a key factor of cytotoxicity of AgNPs in mammalian cells and an important factor in the immune reaction of neutrophils. The immune reactions of neutrophils include the expulsion of webs of DNA surrounded by histones and granular proteins. These webs of DNA are termed neutrophil extracellular traps (NETs). NETs allow neutrophils to catch and destroy pathogens in extracellular spaces. In this study, we investigated how AgNPs stimulate neutrophils, specifically focusing on NETs. Freshly isolated human neutrophils were treated with 5 or 100 nm AgNPs. The 5 nm AgNPs induced NET formation, but the 100 nm AgNPs did not. Subsequently, we investigated the mechanism of AgNP-induced NETs using known inhibitors related to NET formation. AgNP-induced NETs were dependent on ROS, peptidyl arginine deiminase, and neutrophil elastase. The result in this study indicates that treatment of 5 nm AgNPs induce NET formation through histone citrullination by peptidyl arginine deiminase and histone cleavage by neutrophil elastase.


Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2326
Author(s):  
Entesar Ali Ganash ◽  
Reem Mohammad Altuwirqi

In this work, silver nanoparticles (Ag NPs) were synthesized using a chemical reduction approach and a pulsed laser fragmentation in liquid (PLFL) technique, simultaneously. A laser wavelength of 532 nm was focused on the as produced Ag NPs, suspended in an Origanum majorana extract solution, with the aim of controlling their size. The effect of liquid medium concentration and irradiation time on the properties of the fabricated NPs was studied. While the X-ray diffraction (XRD) pattern confirmed the existence of Ag NPs, the UV–Vis spectrophotometry showed a significant absorption peak at about 420 nm, which is attributed to the characteristic surface plasmon resonance (SPR) peak of the obtained Ag NPs. By increasing the irradiation time and the Origanum majora extract concentration, the SPR peak shifted toward a shorter wavelength. This shift indicates a reduction in the NPs’ size. The effect of PLFL on size reduction was clearly revealed from the transmission electron microscopy images. The PLFL technique, depending on experimental parameters, reduced the size of the obtained Ag NPs to less than 10 nm. The mean zeta potential of the fabricated Ag NPs was found to be greater than −30 mV, signifying their stability. The Ag NPs were also found to effectively inhibit bacterial activity. The PLFL technique has proved to be a powerful method for controlling the size of NPs when it is simultaneously associated with a chemical reduction process.


Author(s):  
Yaqiong Qin ◽  
Xiaohui Ji ◽  
Jing Jing ◽  
Hong Liu ◽  
Hongli Wu ◽  
...  

2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
Adnan Haider ◽  
Inn-Kyu Kang

Silver nanoparticles (Ag-NPs) have diverted the attention of the scientific community and industrialist itself due to their wide range of applications in industry for the preparation of consumer products and highly accepted application in biomedical fields (especially their efficacy against microbes, anti-inflammatory effects, and wound healing ability). The governing factor for their potent efficacy against microbes is considered to be the various mechanisms enabling it to prevent microbial proliferation and their infections. Furthermore a number of new techniques have been developed to synthesize Ag-NPs with controlled size and geometry. In this review, various synthetic routes adapted for the preparation of the Ag-NPs, the mechanisms involved in its antimicrobial activity, its importance/application in commercial as well as biomedical fields, and possible application in future have been discussed in detail.


2021 ◽  
pp. 130233
Author(s):  
A. Kalam ◽  
A.G. Al-Sehemi ◽  
S. Alrumman ◽  
M.A. Assiri ◽  
A.M. Alfaify ◽  
...  

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