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High cost and low operational stability are the most important challenges limiting the possible use of laccase in the removal of textile dyes. To overcome these challenges, in this study, polyvinylpyrrolidone (PVP)-coated magnetic nanoparticles (MNPs) were produced and characterized. To our knowledge, this is the first study to explore the feasibility of immobilizing a Trametes trogii laccase enzyme on Fe3O4/PVP MNPs. The characterization of samples and the successful immobilization of laccase were verified by characterization methods. Besides, the biochemical properties and stability of the Fe3O4/PVP/Lac were evaluated in terms of optimum pH, optimum temperature, thermostability, thermodynamic and kinetic parameters, storage stability, operational stability, and decolorization efficiency of two different textile dyes. The optimum activities were recorded at pH 2.5 °C and 30 °C. The Fe3O4/PVP/Lac displayed remarkable thermal stability and activation energy for denaturation, enthalpy, Gibbs free energy, and entropy results confirmed the enhanced stability of Fe3O4/PVP/Lac against high temperatures. Meanwhile, the Fe3O4/PVP/Lac retained about 58% of its original activity after seven consecutive reuses, while it retained up to 25% of its original activity after 28 d of storage at room temperature. Km and Vmax for the Fe3O4/PVP/Lac were calculated to be 126 µM and 211 µmol/min, respectively. Finally, after 8 and 6 cycles of repeated use, the Fe3O4/PVP/Lac still decolorized 32.34% and 32.23% of Remazol Brilliant Blue R (RBBR) and Indigo Carmine (IC), respectively. As envisioned, this study suggests a promising way to solve the problems of high price and poor operational stability of the enzyme during biocatalytic decolorization of textile dyes in wastewaters. [ABSTRACT FROM AUTHOR]

In this study, artificial red blood cells (RBCs) for immobilization of l‐asparaginase are developed. The artificial red blood cells are prepared via a self‐assembly method and characterized by various methods. The prepared material shows a small hydrodynamic size of nearly 120 nm and a zeta potential of ‐7.2 ± 0.2 mV. After l‐asparaginase encapsulation, the particle size is nearly 295 nm and the zeta potential value is ‐9.8 ± 0.1. As expected, the immobilized enzyme shows better pH stability and thermal stability than the free enzyme. For instance, at 60 °C, the immobilized enzyme maintains 63.5% of the original activity, while the free enzyme retains only 27.6% of the original activity. Furthermore, the immobilized enzyme exhibits excellent reusability and storage stability, retaining 46.1% of its initial activity after 15 reuses. Overall, the developed artificial RBCs can potentially be applied as a novel support for immobilization of l‐asparaginase. [ABSTRACT FROM AUTHOR]

Tenofovir alafenamide (TAF) is used as a hepatitis B virus (HBV) nucleotide reverse transcriptase inhibitor for the treatment of chronic HBV infection. However, the use of TAF suffers from its poor solubility and low bioavailability. Therefore, this study prepared and characterized chitosan nanoparticles (CHS NPs) loaded with TAF. Morphological findings demonstrated that CHS NPs are roughly spherical and homogeneous in shape. Besides, TAF‐loaded CHS NPs displayed the hydrodynamic diameter, zeta potential, and PDI of approximately 340 nm, 48.9 mV, and 0.65, respectively. The encapsulation efficiency is at about 50%, and TAF is released about 93% at the end of 80 hours at pH 7.4. In addition, human hepatocellular carcinoma cells (HepG2) are used for cell viability studies and it is observed that TAF‐loaded CHS NPs has 1.24 times less viable cells as compared to the control. Collectively, TAF‐loaded CHS NPs could be used as an efficient formulation for the treatment of chronic HBV infection. [ABSTRACT FROM AUTHOR]

Aim: In December 2019, the coronavirus disease was caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Some drugs were repurposed for this disease treatment. Hydroxychloroquine (HCQ), favipiravir (FAV), molnupiravir (MOL), and dexamethasone (DEX) were widely used for the treatment of the disease. To increase the success of the treatment of coronavirus disease, there was used some of these drugs in combination. On the other hand, limited studies report these drugs' side effects. Therefore, this study was designed to evaluate the possible effects of these drugs and their combinations on the kidney tissues of rats without viral load. Materials and Methods: Male Wistar albino rats were divided into control, HCQ, FAV, HCQ+FAV, HCQ+FAV+DEX, MOL, and MOL+DEX groups. At the end of the experiment, the serum kidney tissue samples were taken. Serum samples were analyzed for urea and creatinine. Kidney tissue samples were assessed as histopathological and immunohistochemical for heat shock protein 60 (HSP60), caspase-3, and receptor-interacting protein kinase-3 (RIPK3). Results: Urea and creatinine levels were within the normal range in all groups. Histopathologically, all drugs and their combinations caused tubular degeneration. On the other hand, histopathological alterations were more prominent in the HCQ group. The oxidative stress marker HSP60 was significantly increased in FAV, MOL, and MOL+DEX groups, while it was similar to the control group in the HCQ groups. Apoptosis marker caspase-3 expression was found to be prominently higher in other drug groups except the FAV group. Expression of RIPK3, a marker of necroptosis, was significantly increased in all drug groups. Conclusion: Taken together, the data of our study show that the administration of all drugs alone and in combination may cause structural damage to the kidney. Furthermore, our results indicate that HCQ can exhibit more damaging effects compared to other drugs. [ABSTRACT FROM AUTHOR]