Publications by authors named "Tanta-Verona Iordache"

7 Publications

  • Page 1 of 1

Eco-Friendly Peelable Active Nanocomposite Films Designed for Biological and Chemical Warfare Agents Decontamination.

Polymers (Basel) 2021 Nov 19;13(22). Epub 2021 Nov 19.

National Institute of Research and Development for Chemistry and Petrochemistry, 202 Splaiul Independentei, 060041 Bucharest, Romania.

In the context of imminent threats concerning biological and chemical warfare agents, the aim of this study was the development of a new method for biological and chemical decontamination, employing non-toxic, film-forming, water-based biodegradable solutions, using a nano sized reagent together with bentonite as trapping agents for the biological and chemical contaminants. Bentonite-supported nanoparticles of Cu, TiO, and Ag were successfully synthesized and dispersed in a polyvinyl alcohol ()/glycerol () aqueous solution. The decontamination effectiveness of the proposed solutions was evaluated by qualitative and quantitative analytical techniques on various micro-organisms, with sulfur mustard () and dimethyl methylphosphonate () as contaminants. The results indicate that the peelable active nanocomposite films can be successfully used on contaminated surfaces to neutralize and entrap the hazardous materials and their degradation products. Mechanical and thermal characterization of the polymeric films was also performed to validate the decontamination solution's potential as peelable-film generating materials. The removal efficacy from the contaminated surfaces for the tested micro-organisms varied between 93% and 97%, while for the chemical agent , the highest decontamination factor obtained was 90.89%. was almost completely removed from the contaminated surfaces, and a decontamination factor of 99.97% was obtained.
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http://dx.doi.org/10.3390/polym13223999DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8620509PMC
November 2021

Mitigating Antibiotic Resistance Genes in Wastewater by Sequential Treatment with Novel Nanomaterials.

Polymers (Basel) 2021 May 15;13(10). Epub 2021 May 15.

Advanced Polymer Materials and Polymer Recycling Group, National Institute for Research & Development in Chemistry and Petrochemistry ICECHIM, Splaiul Independentei 202, 060021 Bucharest, Romania.

Wastewater (WW) has been widely recognized as the major sink of a variety of emerging pathogens (EPs), antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs), which may disseminate and impact wider environments. Improving and maximizing WW treatment efficiency to remove these microbial hazards is fundamentally imperative. Despite a variety of physical, biological and chemical treatment technologies, the efficiency of ARG removal is still far from satisfactory. Within our recently accomplished M-ERA.NET project, novel functionalized nanomaterials, i.e., molecularly imprinted polymer (MIP) films and quaternary ammonium salt (QAS) modified kaolin microparticles, were developed and demonstrated to have significant EP removal effectiveness on both Gram-positive bacteria (GPB) and Gram-negative bacteria (GNB) from WW. As a continuation of this project, we took the further step of exploring their ARG mitigation potential. Strikingly, by applying MIP and QAS functionalized kaolin microparticles in tandem, the ARGs prevalent in wastewater treatment plants (WWTPs), e.g., CTXM, B and S, can be drastically reduced by 2.7, 3.9 and 4.9 log (copies/100 mL), respectively, whereas 1, O and A can be eliminated below their detection limits. In terms of class I integron-integrase I (1), a mobile genetic element (MGE) for horizontal gene transfer (HGT), 4.3 log (copies/100 mL) reduction was achieved. Overall, the novel nanomaterials exhibit outstanding performance on attenuating ARGs in WW, being superior to their control references. This finding provides additional merit to the application of developed nanomaterials for WW purification towards ARG elimination, in addition to the proven bactericidal effect.
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http://dx.doi.org/10.3390/polym13101593DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8157218PMC
May 2021

Poly(β-cyclodextrin)-Activated Carbon Gel Composites for Removal of Pesticides from Water.

Molecules 2021 Mar 6;26(5). Epub 2021 Mar 6.

Coimbra Chemistry Centre, Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal.

Pesticides are widely used in agriculture to increase and protect crop production. A substantial percentage of the active substances applied is retained in the soil or flows into water courses, constituting a very relevant environmental problem. There are several methods for the removal of pesticides from soils and water; however, their efficiency is still a challenge. An alternative to current methods relies on the use of effective adsorbents in removing pesticides which are, simultaneously, capable of releasing pesticides into the soil when needed. This reduces costs related to their application and waste treatments and, thus, overall environmental costs. In this paper, we describe the synthesis and preparation of activated carbon-containing poly(β-cyclodextrin) composites. The composites were characterized by different techniques and their ability to absorb pesticides was assessed by using two active substances: cymoxanil and imidacloprid. Composites with 5 and 10 wt% of activated carbon showed very good stability, high removal efficiencies (>75%) and pesticide sorption capacity up to ca. 50 mg g. The effect of additives (NaCl and urea) was also evaluated. The composites were able to release around 30% of the initial sorbed amount of pesticide without losing the capacity to keep the maximum removal efficiency in sorption/desorption cycles.
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http://dx.doi.org/10.3390/molecules26051426DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7962014PMC
March 2021

Molecularly imprinted films and quaternary ammonium-functionalized microparticles working in tandem against pathogenic bacteria in wastewaters.

J Hazard Mater 2020 11 27;399:123026. Epub 2020 May 27.

National Institute for Research & Development in Chemistry and Petrochemistry ICECHIM, Advanced Polymer Materials and Polymer Recycling Group, Splaiul Independentei 202, 060021, Bucharest, Romania. Electronic address:

Despite major efforts to combat pollution, the presence of pathogenic bacteria is still detected in surface water, soil and even crops due to poor purification of domestic and industrial wastewaters. Therefore, we have designed molecularly imprinted polymer films and quaternary ammonium-functionalized- kaolin microparticles to target specifically Gram-negative bacteria (GNB) and Gram-positive bacteria (GPB) in wastewaters and ensure a higher purification rate by working in tandem. According to the bacteriological indicators, a reduction by 90 % was registered for GNB (total coliforms and Escherichia coli O157) and by 77 % for GPB (Clostridium perfringens) in wastewaters. The reduction rates were confirmed when using pathogen genetic markers to quantify particular types of GNB and GPB, like Salmonella typhimurium (reduction up to 100 %),Campylobacter jejuni (reduction up to 70 %), Enterococcus faecalis (reduction up to 81 %), Clostridium perfringens (reduction up to 97 %) and Shiga toxin-producing Escherichia coli (reduction up to 64 %). In order to understand the bactericidal activity of prepared films and microparticles, we have performed several key analyses such as Cryo-TEM, to highlight the auto-assembly mechanism of components during the films formation, and Si/ C CP/MAS NMR, to reveal the way quaternary ammonium groups are grafted on the surface of kaolin microparticles.
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http://dx.doi.org/10.1016/j.jhazmat.2020.123026DOI Listing
November 2020

Composite Nanogels Based on Zeolite-Poly(ethylene glycol) Diacrylate for Controlled Drug Delivery.

Nanomaterials (Basel) 2020 Jan 22;10(2). Epub 2020 Jan 22.

Advanced Polymer Materials and Polymer Recycling Group, National Institute for Research and Development in Chemistry and Petrochemistry-ICECHIM, 202 Spl. Independentei, 6th District, P.O. Box 35/174, 060021 Bucharest, Romania.

This study presents the design of novel composites nanogels, based on poly(ethylene glycol) diacrylate and natural zeolite particles, that are able to act as materials with controlled drug delivery properties. Natural zeolite‒nanogels composite, with varying zeolite contents, were obtained by an inverse mini-emulsion technique and loaded with 5-fluorouracil, a widely used chemotherapeutic drug. Herein, the possibility of adjusting final properties by means of modifying the preparation conditions was investigated. The prepared composite nanogels are characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). In light of this tunable drug-loading capability, swelling behaviour, and cytotoxicity, these composite nanogels could be highly attractive as drug reservoirs.
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http://dx.doi.org/10.3390/nano10020195DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7075022PMC
January 2020

Straightforward Preparation of Naphtodianthrone-Rich Ethanolic Extracts from Wild St. John's Wort.

J Diet Suppl 2020 31;17(1):88-96. Epub 2018 Oct 31.

National Institute for Research & Development in Chemistry and Petrochemistry ICECHIM, Advanced Polymer Materials and Polymer Recycling Group, Bucharest, Romania.

Separation of naphtodianthrones (NTs) from Hypericum perforatum L. (aerial part of St. John's Wort) is still topical due to some hard-to-beat medicinal attributes of these bioactive compounds. Unfortunately, their low bioavailability (0.06%-0.4%) complicates the extraction process. Therefore, developing straightforward and lower-cost methodologies for NT separation is still a priority. In support of this purpose, for preparing NT formulations from flowers and leaves of wild St. John's Wort (hyperici herba), a cutoff preparative methodology is described herein. Combining Soxhlet extraction and reflux extraction, some concentrated and rather pure NT ethanolic-based formulations without chlorophyl and grease were obtained.
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http://dx.doi.org/10.1080/19390211.2018.1484404DOI Listing
September 2020

An innovative approach to prepare hypericin molecularly imprinted pearls using a "phyto-template".

Talanta 2016 23;148:37-45. Epub 2015 Oct 23.

National Research and Development Institute for Chemistry and Petrochemistry INCDCP-ICECHIM, Advanced Polymer Materials and Polymer Recycling, 202 Splaiul Independentei, 060021 Bucharest, Romania. Electronic address:

In this paper, an innovative method that uses hypericin "phyto-template" molecules is being applied herein for the first time to produce molecularly imprinted polymer (MIP) pearls able to selectively retain hypericin from Hypericum Perforatum L primary extracts. For this purpose, the wet phase inversion method was preferred for preparing the hypericin-MIP pearls for several reasons referring to economical benefits but also due to the fact that hypericin "phyto-template" molecules can be generated along with the phase inversion of the copolymer. Practically, the precursor poly(acrylonitrile-co-methacrylic acid) solution was mixed with a purified and concentrated naphtodianthrone phyto-extract (consisting only of hypericin and pseudo-hypericin). In the subsequent phase inversion step hypericin was trapped in the copolymer droplets, as a result to its poor solubility in the inversion water bath, and further served as "phyto-template" in the imprinting step. This in situ repartition of hypericin and pseudo-hypericin was sustained by HPLC-DAD chromatograms which recorded only the presence of hypericin during the extraction stage of imprinted pearls. Batch rebinding measurements, all together, validated the efficiency of this innovative imprinting procedure. The hypericin rebinding of imprinted pearls was quantitative (up to 318 µg/L) and approximately 5 times more specific relative to the blank pearls. Competitive re-binding revealed a more selective behaviour of imprinted pearls for hypericin when the up-take was measured against pseudohypericin (selectivity coefficient above 4.50).
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http://dx.doi.org/10.1016/j.talanta.2015.10.061DOI Listing
September 2016
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