Silver nanoparticles assessment in moisturizing creams by ultrasound assisted extraction followed by sp-ICP-MS

Protein corona-induced extraction coupled to Fenton oxidation for selective and non-destructive preconcentration of Ag2S nanoparticles from waters

Sulfidation of silver nanoparticles (AgNPs) to generate silver sulfide nanoparticles (Ag₂S-NPs) significantly influences their fate and toxicity in natural environments. However, the correlational research in this field was limited by the lack of methods for speciation analysis of Ag₂S-NPs. To address this challenge, a novel protocol for the selective Ag₂S-NP extraction from real waters was developed using protein corona-induced extraction coupled to Fenton oxidation of AgNPs with Fe³⁺/H₂O₂ reagents. The ability of various concentrations of Fe³⁺/H₂O₂ to selectively dissociate AgNPs into ions was first evaluated. Then, selective separation and preconcentration of the remaining Ag₂S-NPs was established by optimizing the parameters that may affect the protein corona-induced extraction efficiency, followed by quantification with inductively coupled plasma mass spectrometry (ICP-MS), enabling an ultrahigh enrichment factor of 10,000 and extremely low detection limit (LOD) of 1.8 ng/L. The presence of humic acid (HA), inorganic salts and particles at the environmentally relevant levels had limited effects on Ag₂S-NP extraction. As demonstrated by transmission electron microscopy (TEM) analysis and single particle ICP-MS (spICP-MS), the sizes, shapes, and compositions of Ag₂S-NPs extracted with the proposed method remain in intact. Good recoveries of 83.7-105% were achieved for the Ag₂S-NPs spiked in four natural waters at the level of 97.8 ng/L. Due to the high yields and applicability to Ag₂S-NPs at environmentally relevant concentrations, this proposed method is particularly suitable to track the generation and transformation of Ag₂S-NPs in various scenarios.

Study Design on the Presence of Metals in Moisturisers, and Compliance with Regulation (EC) No. 1223/2009 of the European Parliament and of the Council of the European Union, on Cosmetic Products

Metals are present in cosmetics due to deliberate addition by the manufacturers, contamination of raw materials, and/or contamination during their manufacture or storage. The objective of this work was to explore the metal content in the most-consumed moisturising creams on the Spanish market, to verify their degree of compliance with Regulation (EC) No. 1223/2009 of the European Parliament and of the Council of the European Union, regarding the presence of metals in cosmetics. The moisturisers were digested (microwave-assisted acid digestion) and analysed by inductively coupled plasma-mass spectrometry (ICP-MS), for metal assessment. The ICP-MS measurements were successfully validated (RSDs lower than 5% and analytical recoveries within the 91–110% range). Metals banned in cosmetics were found at very low concentrations in some of the moisturisers, as inevitable traces of pollutants. This was the case with beryllium (found in only two samples, at concentrations lower than 0.10 µg g−1), cadmium (found at 0.075 µg g−1 in one sample), mercury (found in four samples at concentrations within the 0.10–0.18 µg g−1 range), and lead (also found in four samples at concentrations from 0.03 to 0.44 µg g−1). Furthermore, nickel (0.16–0.56 µg g−1, six samples), chromium (0.09–0.30 µg g−1, three samples), and cobalt (lower than 0.13 µg g−1, two samples) were also found in the analysed creams.

ICP-MS Determination of Antimicrobial Metals in Microcapsules

Silver (Ag) and zinc (Zn) are very powerful antimicrobial metals. Therefore, in this research, a high-throughput, sensitive, and rapid method was developed for the determination of Ag and Zn in microcapsules using inductively coupled plasma mass spectrometry (ICP-MS). The sample preparation procedure employed simple microwave digestion of the microcapsules with 55.55% v/v HNO3 and 44.45% v/v H2O2. The method was applied to determine Ag and Zn in microcapsule samples of different sizes (120 and 450 μm) after their preparation with and without chitosan. Prepared microcapsules, after characterization, were bonded to a polymer carrier by sol-gel procedure and the materials were characterized by FTIR spectroscopy and high-resolution optical microscopy. Significant differences were found in Ag and Zn levels between microcapsules samples prepared with and without chitosan. The results have shown that samples with chitosan had up to 20% higher levels of Zn than Ag: 120 μm microcapsules contained 351.50 μg/g of Ag and 85.51 μg/g of Zn, respectively. In contrast, samples prepared without chitosan showed larger overall variability: In microcapsules with a diameter of 120 μm, the amounts of antimicrobial metals were 98.32 μg/g of Ag and 106.75 μg of Zn, respectively. Moreover, 450 μm microcapsules contained 190.98 μg/g of Ag and 121.35 μg/g of Zn. Those quantities are high enough for efficient antimicrobial activity of newly prepared microcapsules, enabling the application of microcapsules in different antimicrobial coatings.

Biogenic silver nanoparticles in the treatment of experimental pythiosis Bio-AgNP in pythiosis therapy

Pythiosis is a rapidly progressing disease that can be lethal to affected individuals due to resistance to available therapeutic protocols. The disease affects mammals, with the largest number of reports in horses and humans. The present study investigated the activity of biogenic silver nanoparticles (bioAgNP) in the treatment of experimental pythiosis. The disease was reproduced in nine female 90-day-old New Zealand rabbits. Animals were divided into three groups: group1 (control, n = 3) daily and topically treated with a nonionized gel-based formulation and 1 ml of sterile distilled water intralesion administered every 48 hours; group 2 (n = 3), daily and topically treated with gel-based formulation containing 1 μg/ml bio-AgNP; group 3 (n = 3), treated with 1 ml bio-AgNP in 1 μg/ml aqueous solution intralesion administered every 48 hours. Animals were treated for 45 days, and the area of subcutaneous lesions was measured every 5 days. Results showed that groups 2 and 3 differed from control group (P < .05) in the lesion area, as well as the amount of hyphae within the lesions. It was observed that lesions of treated animals (groups 2 and 3) did not differ from each other, showing that the application route did not influence the regression of lesions. However, it was observed that one animal from group 2 reached clinical cure at 35 days of treatment. This research is pioneer in the application of nanocomposites for the treatment of experimental pythiosis and showed that bio-AgNP can be powerful allies of integrative medicine and can be included in pythiosis therapeutic protocols.

An anthraquinone-imidazole-based colorimetric and fluorescent sensor for the sequential detection of Ag+ and biothiols in living cells

An anthraquinone-imidazole-based highly selective colorimetric and fluorescent sensor for the sequential detection of Ag⁺ and biothiols in living cells is reported.

Nanotechnology meets atopic dermatitis: Current solutions, challenges and future prospects. Insights and implications from a systematic review of the literature

Atopic dermatitis is a chronic, relapsing, non-contiguous, exudative eczema/dermatitis, which represents a complex, multi-factorial disorder, due to an impairment of the stratum corneum barrier. Currently available drugs have a low skin bioavailability and may give rise to severe adverse events. Nanotechnologies, including nano-particles, liposomes, nano-gels, nano-mixtures, nano-emulsions and other nano-carriers, offer unprecedented solutions to these issues, enabling: i) the management of different clinical forms of atopic dermatitis, especially the recalcitrant ones, i) a better bio-availability and trans-dermal drug targeted delivery at the inflammation site, ii) dose control, iii) significant improvements both in clinical symptoms and immune responses, iv) with less adverse events being reported and a better safety profile. However, some nano-sized structures could amplify and even worsen symptoms in particularly susceptible individuals. Furthermore, most studies included in the present systematic review have been conducted in-vitro or in-vivo, with few randomized controlled clinical trials (RCTs). Future investigations should adopt this design in order to enable scholars achieving robust findings and evidence. Therefore, given the above-mentioned shortcomings, further research in the field is urgently warranted.

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Atopic dermatitis is a chronic, relapsing eczema/dermatitis, due to an impairment of the stratum corneum barrier.

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Currently available drugs have a low skin bioavailability and may give rise to severe adverse events.

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Nanotechnologies offer unprecedented solutions, enabling the management of different clinical forms of atopic dermatitis.