Degradation of diclofenac sodium using UV/biogenic selenium nanoparticles/H2O2: Optimization of process parameters

Biogenic Selenium Nanoparticles in Biomedical Sciences: Properties, Current Trends, Novel Opportunities and Emerging Challenges in Theranostic Nanomedicine

Selenium is an important dietary supplement and an essential trace element incorporated into selenoproteins with growth-modulating properties and cytotoxic mechanisms of action. However, different compounds of selenium usually possess a narrow nutritional or therapeutic window with a low degree of absorption and delicate safety margins, depending on the dose and the chemical form in which they are provided to the organism. Hence, selenium nanoparticles (SeNPs) are emerging as a novel therapeutic and diagnostic platform with decreased toxicity and the capacity to enhance the biological properties of Se-based compounds. Consistent with the exciting possibilities offered by nanotechnology in the diagnosis, treatment, and prevention of diseases, SeNPs are useful tools in current biomedical research with exceptional benefits as potential therapeutics, with enhanced bioavailability, improved targeting, and effectiveness against oxidative stress and inflammation-mediated disorders. In view of the need for developing eco-friendly, inexpensive, simple, and high-throughput biomedical agents that can also ally with theranostic purposes and exhibit negligible side effects, biogenic SeNPs are receiving special attention. The present manuscript aims to be a reference in its kind by providing the readership with a thorough and comprehensive review that emphasizes the current, yet expanding, possibilities offered by biogenic SeNPs in the biomedical field and the promise they hold among selenium-derived products to, eventually, elicit future developments. First, the present review recalls the physiological importance of selenium as an oligo-element and introduces the unique biological, physicochemical, optoelectronic, and catalytic properties of Se nanomaterials. Then, it addresses the significance of nanosizing on pharmacological activity (pharmacokinetics and pharmacodynamics) and cellular interactions of SeNPs. Importantly, it discusses in detail the role of biosynthesized SeNPs as innovative theranostic agents for personalized nanomedicine-based therapies. Finally, this review explores the role of biogenic SeNPs in the ongoing context of the SARS-CoV-2 pandemic and presents key prospects in translational nanomedicine.

Pharmaceutical residues: One of the significant problems in achieving 'clean water for all' and its solution

With the rapid emergence of various metabolic and multiple-drug-resistant infectious diseases, new pharmaceuticals are continuously being introduced in the market. The excess production and use of pharmaceuticals and their untreated/unmetabolized release in the environment cause the contamination of aquatic ecosystem, and thus, compromise the environment and human-health. The present review provides insights into the classification, sources, occurrence, harmful impacts, and existing technologies to curb these problems. A comprehensive detail of various biological and nanotechnological strategies for the removal of pharmaceutical residues from water is critically discussed focusing on their efficiencies, and current limitations to design improved-technologies for their lab-to-field applications. Furthermore, the review highlights and suggests the scope of integrated bionanotechnological methods for enhanced removal of pharmaceutical residues from water to fulfill the United Nations Sustainable Development Goal (UN-SDG) for providing clean potable water for all.

Effect of advanced/hybrid oxidation process involving ultrasonication and ultraviolet radiation (sonophotolysis) on anthocyanin stability: Degradation kinetics and mechanism

The hybrid oxidation effect of ultrasonics (US) and ultraviolet light (UV-A) on Cyanidin-3-O-glucoside (C3G) stability were examined. For comparison, sonolysis and photolysis experiments were also conducted. The results showed that under hybrid sonophotolysis and sonolysis treatment, C3G degradation undergoes zero-order kinetics, while under photolysis, first-order degradation kinetic prevailed. The degradation rate increases with the increase in US power, with the lowest, was recorded as 0.70 μg/ml/h (14 W/L) and 0.77 μg/ml/h (28 W/L), and highest as 0.80 μg/ml/h (42 W/L). Similarly, the degradation ability of UV photolysis at 400 μW/cm² was weak, which increased with increasing UV power (600 μW/cm²). Overall the sonophotolysis degradation rate was significantly higher than that of the individual effect. With the addition of gallic acid (GA), the degradation of C3G was found lower under sonophotolysis; thus, it could be used as a natural protective agent for C3G during food processing.

Understanding the factors affecting adsorption of pharmaceuticals on different adsorbents - A critical literature update

Remediation of emerging pharmaceutically active compounds (PhACs) as micropollutants in wastewater is of foremost importance as they can cause extremely detrimental effects on life upon bioaccumulation and generation of drug-resistance microorganisms. Presently used physicochemical treatments, such as electrochemical oxidation, nanofiltration and reverse osmosis, are not feasible owing to high operating costs, incomplete removal of contaminants along with toxic by-products formation. Adsorption with the utilization of facile and efficient nanoparticulate adsorbents having distinctive properties of high surface area, excellent adsorption capacity, ability to undergo surface engineering and good regeneration displays great potential in this aspect along with the incorporation of nanotechnology for effective treatment. The application of such nanosorbents provides optimal performance under a wide range of physicochemical conditions, decreased secondary pollution with reduced mechanical stress along with excellent organic compound sequestration capacity, which in turn improves the quality of potable water in a sustainable way compared to current treatments. The present review intends to consolidate the range of factors that affect the process of adsorption of different PhACs on to various nanosorbents and also highlights the adsorption mechanism aiding in the retrieval.

Rapid microwave-assisted biosynthesis of platinum nanoparticles and evaluation of their antioxidant properties and cytotoxic effects against MCF-7 and A549 cell lines

In this study, platinum nanoparticles (Pt NPs) were synthesized by a green method using an aqueous extract of Eucalyptus camaldulensis with assistance of microwave irradiation (850 W) and their physicochemical characteristics were studied by UV-visible spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) analyses. Antioxidant activities, hemocompatibility, and cytotoxic effects of the prepared Pt NPs were then evaluated. The attained results showed that the newly formed Pt NPs possess a size range between 7.4 and 11.2 nm. These spherical-shaped NPs were slightly aggregated and held various functional groups on their surface. The antioxidant activity of Pt nanostructures was comparable to that of butylated hydroxyl anisole at concentrations higher than 320 µg/mL. At the same concentration of 640 μg/mL, the scavenging activities were 3.36 ± 0.9% (hexachloroplatinic acid) and 52.13 ± 0.43% (Pt NPs). The results of hemolytic assay revealed satisfactory hemocompatibility of the Pt NPs even at the concentration as high as 4 mg/mL (hemolysis percent equal to 3.5 ± 1.3%). The cytotoxicity studies revealed that MCF-7, A549, and 3T3 cell lines treated with hexachloroplatinic acid and cisplatin for 24 h and 48 h showed a higher percentage of cell death compared with the Pt NPs. After 24 h, for A549, 3T3, and MCF-7 cells exposed to Pt NPs, the cell viability was measured to be 80 ± 3.2%, 96 ± 1%, and 89 ± 2.6%, respectively, at concentration of 640 µg/mL. Further investigations are required to elucidate the mechanisms behind the biological activities of as-synthesized Pt NPs.

Comprehensive Characterization of 76 Pharmaceuticals and Metabolites in Wastewater by LC-MS/MS

Wastewaters are considered one of the main sources of pollution in the aquatic environment as release a large number of contaminants every day. Emerging contaminants such as pharmaceuticals have special interest due to the high levels of consumption by the global population, their bioactive properties and because actual directives do not include the monitoring of pharmaceuticals. Moreover, it is well-known that pharmaceuticals can be degraded to metabolites or transformation products (TPs), which could be more toxic than the parental compound. In this study, we have developed an analytical method based on solid-phase extraction (SPE) and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) to determine 76 highly consumed pharmaceuticals, including metabolites and TPs in wastewater effluents. In the 10 wastewaters analysed, the mean concentrations were in the µg L−1 levels, being mycophenolic acid, levodopa, ibuprofen, 4-aminoantypirine, losartan, amylmetacresol, amoxicillin, fluticasone, tramadol, budesonide, chlorpheniramine and diclofenac the pharmaceuticals with the highest concentrations. This study provides a comprehensive optimization on the MS conditions to determine pharmaceutical compounds and their metabolites and provides a spectral characterization to be used for the identification of these compounds in water.

Degradation of diclofenac sodium using Fenton-like technology based on nano-calcium peroxide

A nano-calcium peroxide (nCaO₂) powder with a purity of 89.1% was prepared using an improved traditional method. Then, the as-prepared nCaO₂ was used as the source of hydrogen peroxide (H₂O₂) for the Fenton-like degradation of diclofenac sodium (DCF). The results showed that nCaO₂ performed better for DCF removal when compared to nCaO₂ prepared by a conventional method and commercial calcium peroxide (CaO₂). Further experimental results indicated that 97.5% of DCF could be removed in 180 min at a nCaO₂/Fe²⁺-EDTA/DCF molar ratio of 16/8-8/1, which was more efficient than in the H₂O₂/EDTA-Fe²⁺/DCF and nCaO₂/Fe²⁺/DCF systems. The best removal rate of DCF was at pH 6.0, unlike previous claims that stated that the lower the pH in the buffer system, the better the degradation of DCF. In addition, the influence of water quality parameters, such as Cl^-, NO₃^-, SO₄^2-, HCO₃^-, and humic acid (HA), on DCF removal were evaluated. A free radical masking experiment revealed the existence of hydroxyl radical (OH), superoxide radical (O₂^-) and singlet oxygen (¹O₂), and indicated that the degradation of DCF was mainly due to oxidation caused by OH. Electron paramagnetic resonance (EPR) studies for different systems and different active oxygen species were carried out, and it was further confirmed that OH radicals have high intensity in the Fenton-like system based on nCaO₂. EPR results also showed that the addition of EDTA can promote the production of OH. According to the identification of the dominant reactive species and GC-MS, the possible theoretical DCF degradation pathways were proposed.

Kinetics and reaction mechanism of photochemical degradation of diclofenac by UV-activated peroxymonosulfate

Diclofenac (DCF) is a common non-steroidal anti-inflammatory drug, which is frequently detected in different environmental media such as surface water, groundwater, domestic sewage, and sediment. In this study, UV-activated peroxymonosulfate (PMS) was used to degrade DCF by generating active radicals (i.e., SO₄˙⁻ and HO˙) with strong oxidizing properties. The effects of PMS dosage, pH, initial DCF concentration and common water constituents on the removal of DCF as well as its degradation mechanism in UV/PMS system were investigated. Compared to UV alone and PMS alone systems, DCF was removed more efficiently in the UV/PMS system at pH 7.0 due to the contribution of SO₄˙⁻ and HO˙, and its degradation followed the pseudo-first order kinetic model. As the dosage of PMS or solution pH increased, the degradation efficiency of DCF was gradually enhanced. The highest DCF degradation was obtained at pH 11.0 in this study, because the molar absorption coefficient of PMS increased with increasing pH at 254 nm resulting in generation of more reactive radicals at high pH. Removal efficiency of DCF was decreased significantly with the increase in its initial concentration due to the insufficient concentration of radicals. The presence of HCO₃⁻ and NO₃⁻ could promote the degradation of DCF because of the role of carbonate radicals and extra HO˙ formed, respectively, while NOM inhibited DCF degradation due to its competition with DCF for reactive radicals. No obvious influence on DCF degradation was observed in the UV/PMS system with the addition of Cl⁻ and SO₄²⁻. The degradation of DCF by UV/PMS in real waters was slightly suppressed compared with its removal in ultrapure water. Seven transformation products were detected using UPLC-QTOF/MS, and the potential degradation mechanism of DCF was thus proposed showing six reaction pathways including hydroxylation, decarboxylation, dechlorination–cyclization, formylation, dehydrogenation and dechlorination–hydrogenation.

Compared to UV alone and PMS alone systems, diclofenac was removed more efficiently in UV/PMS system at pH 7.0 due to the contribution of SO₄˙⁻ and HO˙ and its degradation followed the pseudo-first order kinetic model.