An injectable supramolecular hydrogel hybridized with silver nanoparticles for antibacterial application

Soft Matter ◽  
2018 ◽  
Vol 14 (7) ◽  
pp. 1227-1234 ◽  
Author(s):  
Yanli Niu ◽  
Tiantian Guo ◽  
Xiaoyan Yuan ◽  
Yunhui Zhao ◽  
Lixia Ren

Silver nanoparticle hybrid supramolecular hydrogels were prepared by in situ reduction of AgNO3 in the presence of PPEGMA-ran-PAA followed by complexation with α-CDs. The resulting injectable hydrogels showed excellent inhibition for bacteria.

2020 ◽  
Author(s):  
Yong Huang ◽  
Liping Zhong ◽  
Zhiming Deng ◽  
Pan Wu ◽  
Jian He ◽  
...  

Abstract In this study we show for the first time that a reduced graphene oxide (rGO) carrier has a 15-fold higher catalysis rate than graphene oxide (GO) in Ag+ reduction. Based on this, we constructed a tumor microenvironment-enabled in situ silver-based electrochemical oncolytic bioreactor (SEOB) which unlocked an Ag+ prodrug to generate silver nanoparticles and inhibited the growth of various tumors. In this bioreactor system, intratumoral H2O2 acted as the reductant and the rGO carrier acted as the catalyst. Chelation of aptamers to this prodrug increased the production of silver nanoparticles by tumor cells, especially in the presence of Vitamin C, which broke down in tumor cells to supply massive amounts of H2O2. Consequently, highly efficient silver nanoparticle-induced apoptosis was observed in HepG2 and A549 cells in vitro and in HepG2- and A549-derived tumors in vivo. The apoptosis was associated with ROS-induced changes in mitochondrial membrane potential and DNA damage. The specific aptamer targeting and intratumoral silver nanoparticle production guaranteed excellent biosafety, with no damage to normal cells, because the Ag+ prodrug was specifically unlocked in tumors. More significantly, there was no evident tissue damage in monkeys, which greatly increases the clinical translation potential of the SEOB system.


e-Polymers ◽  
2011 ◽  
Vol 11 (1) ◽  
Author(s):  
Yingbo Chen ◽  
Lina Liu ◽  
Yufeng Zhang

AbstractPoly(vinylidene fluoride)-silver nanoparticle (PVDF-Ag) composites were synthesized by in situ reduction of silver salt using dimethylformide (DMF) as both a solvent and a reductant. The crystalline properties (e.g., crystallinity and the types of crystals) of the composites were characterized. It was shown that PVDF in the composites had a higher melting temperature than pure PVDF, and the α phase crystal in the composites became more stable with an increase in the amount of silver nanoparticles. The mechanical properties and morphologies of the composites were also investigated. It was noted that the PVDF-Ag composites have better mechanical properties when silver nanoparticles were added. The increase in toughness could be attributed to the formation of continuous structure between PVDF and silver particles.


Nanoscale ◽  
2018 ◽  
Vol 10 (24) ◽  
pp. 11485-11490 ◽  
Author(s):  
Claudia Kästner ◽  
Patrick E. J. Saloga ◽  
Andreas F. Thünemann

We report on etching of polyacrylic acid-stabilised silver nanoparticles in the presence of glutathione (GSH). The kinetics of the etching of the initial particles, accompanied by formation of smaller silver particles was interpreted based on in situ, time-resolved small-angle X-ray scattering (SAXS) experiments.


2021 ◽  
Vol 11 (6) ◽  
pp. 2463
Author(s):  
Sun-Hwa Nam ◽  
Jin Il Kwak ◽  
Youn-Joo An

Various pollutants are pervasive in soil environments due to human activities, thereby damaging soil ecosystems. In this study, extension of a previously developed algae-soaked disc seeding assay for periodic evaluation of subsoil contamination over time was described. The assay can be used in different contamination configurations of silver nanoparticles in combination with examination of cell morphology, esterase activity, oxidative stress, and membrane permeability. In addition, we periodically attempted to repeat the algae-soaked disc seeding assay every three weeks. We evaluated applicability of this algae-soaked disc seeding assay using alga Chlamydomonas reinhardtii exposed to heterogeneous silver nanoparticle-contaminated soils. The results demonstrated that this assay is applicable for monitoring a change of subsoil contamination by periodic evaluation over time. The developed assay was identified as a periodically rapid in situ biomonitoring technique to measure subsoil contamination over time.


2020 ◽  
Vol 17 (36) ◽  
pp. 159-170
Author(s):  
Eli ROHAETI ◽  
Nur Isna Melati PUTRI ◽  
Kun Sri BUDIASIH ◽  
Anna RAKHMAWATI

Improving leather quality with antifungal, antibacterial, and superior mechanical properties is an ongoing effort. The objectives of this research were to synthesize silver nanoparticle using Cyperus kyllinga extract as a bio-agent and to deposit synthesized silver nanoparticle into goat leather by ex situ and in situ, and also to characterize the properties of antibacterial, antifungal, mechanical, and contact angle of goat leather before and after modification. Preparation of silver nanoparticles by reduction method by adding Cyperus kyllinga’s leaf extract. The silver nanoparticle was characterized by using spectrophotometer UltraViolet-Visible and Particle Size Analyzer. The addition of Methyltrimethoxysilane (MTMS) compound on the leather sample to know hydrophobicity properties of the leather. The leather was modified by adding silver nanoparticle and silane compounds. The antibacterial and antifungal test was conducted by the diffusion method and tested the significance by using statistical analysis. The mechanical properties were tested through tensile strength test, elongation, and also modulus Young by using a tensile tester. The modified goat leather surface was tested the contact angle by using the sessile drop method. The characterization results indicated that silver nanoparticles were formed at a wavelength of 406.60 nm, with their particle size were 200.1 nm. The results of the antimicrobial test showed that modified goat leather using two methods of preparation had a different significance to inhibit the S. epidermidis and E. coli, and also fungi of C. albicans. The leather, after modification with nanoparticle via in situ method, had the highest antibacterial activities against S. epidermidis and E. coli. However, leather after modification with adding nanoparticle and MTMS via ex situ method has the highest antifungal activity against C. albicans. The leather after modification nanoparticle and MTMS via in situ method has the highest tensile strength and the largest toughness. All modified leathers had larger antimicrobial activity, contact angle, and also toughness compared to unmodified leather.


Author(s):  
С.И. Каба ◽  
А.А. Соколовская

Продемонстрировано обнаружение наночастиц серебра во внутриклеточном пространстве с помощью проточной цитофлуориметрии. В эндотелиальных клетках линии EA.hy926, инкубированных в растворе, содержащем 2 мкг/мл наносеребра, измеряли боковое светорассеяние. По сравнению с контрольными образцами этот параметр возрастал, в то время как прочие значимые характеристики не изменялись. Это подтверждает чувствительность метода к изменившемуся состоянию клеток и указывает на поглощение наночастиц серебра клетками при концентрации ниже токсической. The study demonstrated a possibility for detection of intracellular silver nanoparticles using flow cytometry. The parameter used in this work, side scattering, was measured in EA.hy926 endothelial cells incubated in a 2 mg/ml silver nanoparticle solution. This parameter was increased compared to control samples. Therefore, this technique was sensitive to changes in the cell status and suggested the cell uptake of the particles under the subtoxic conditions.


Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1428
Author(s):  
Agnieszka Pluta-Kubica ◽  
Ewelina Jamróz ◽  
Gohar Khachatryan ◽  
Adam Florkiewicz ◽  
Pavel Kopel

There is a serious need to develop and test new biodegradable packaging which could at least partially replace petroleum-based materials. Therefore, the objective of this work was to examine the influence of the recently developed furcellaran nanocomposite film with silver nanoparticles (obtained by an in situ method) on the quality properties of two cheese varieties: a rennet-curd (gouda) and an acid-curd (quark) cheese. The water content, physicochemical properties, microbiological and organoleptic quality of cheese, and migration of silver nanoparticles were examined. Both the number of Lactococcus and total bacteria count did not differ during storage of gouda regardless of the packaging applied. The number of Lactococcus decreased in analogous quark samples. The use of the film slowed down and inhibited the growth of yeast in gouda and quark, respectively. An inhibitory effect of this film on mold count was also observed; however, only regarding gouda. The level of silver migration was found to be lower in quark than in gouda. The film improved the microbiological quality of cheeses during storage. Consequently, it is worth continuing research for the improvement of this film in order to enable its use in everyday life.


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