Dose-response and type-dependent effects of antiviral drugs in anaerobic digestion of waste-activated sludge for biogas production.

In the context of the COVID-19 pandemic, antiviral drugs (AVDs) were heavily excreted into wastewater and subsequently enriched in sewage sludge due to their widespread use. The potential ecological risks of AVDs have attracted increasing attention, but information on the effects of AVDs on sludge anaerobic digestion (AD) is limited. In this study, two typical AVDs (lamivudine and ritonavir) were selected to investigate the responses of AD to AVDs by biochemical methane potential tests. The results indicated that the effects of AVDs on methane production from sludge AD were dose- and type-dependent. The increased ritonavir concentration (0.05-50 mg/kg TS) contributed to an 11.27-49.43% increase in methane production compared with the control. However, methane production was significantly decreased at high lamivudine doses (50 mg/kg TS). Correspondingly, bacteria related to acidification were affected when exposed to lamivudine and ritonavir. Acetoclastic and hydrotropic methanogens were inhibited at a high lamivudine dose, while ritonavir enriched methylotrophic and hydrotropic methanogens. Based on the analysis of intermediate metabolites, the inhibition of lamivudine and the promotion of ritonavir on acidification and methanation were confirmed. In addition, the existence of AVDs could affect sludge properties. Sludge solubilization was inhibited when exposed to lamivudine and enhanced by ritonavir, perhaps caused by their different structures and physicochemical properties. Moreover, lamivudine and ritonavir could be partially degraded by AD, but 50.2-68.8% of AVDs remained in digested sludge, implying environmental risks.

Solubilized curcuminoid complex prevents extensive immunosuppression through immune restoration and antioxidant activity: Therapeutic potential against SARS-CoV-2 (COVID-19).

The therapeutic benefits of curcuminoids in various diseases have been extensively reported. However, little is known regarding their preventive effects on extensive immunosuppression. We investigated the immunoregulatory effects of a curcuminoid complex (CS/M), solubilized with stevioside, using a microwave-assisted method in a cyclophosphamide (CTX)-induced immunosuppressive mouse model and identified its new pharmacological benefits. CTX-treated mice showed a decreased number of innate cells, such as dendritic cells (DCs), neutrophils, and natural killer (NK) cells, and adaptive immune cells (CD4 and CD8 T cells) in the spleen. In addition, CTX administration decreased T cell activation, especially that of Th1 and CD8 T cells, whereas it increased Th2 and regulatory T (Treg) cell activations. Pre-exposure of CS/M to CTX-induced immunosuppressed mice restored the number of innate cells (DCs, neutrophils, and NK cells) and increased their activity (including the activity of macrophages). Exposure to CS/M also led to the superior restoration of T cell numbers, including Th1, activated CD8 T cells, and multifunctional T cells, suppressed by CTX, along with a decrease in Th2 and Treg cells. Furthermore,CTX-injected mice pre-exposed to CS/M were accompanied by an increase in the levels of antioxidant enzymes (superoxide dismutase, catalase, and glutathione peroxidase), which play an essential role against oxidative stress. Importantly, CS/M treatment significantly reduced viral loads in severe acute respiratory syndrome coronavirus2-infected hamsters and attenuated the gross pathology in the lungs. These results provide new insights into the immunological properties of CS/M in preventing extensive immunosuppression and offer new therapeutic opportunities against various cancers and infectious diseases caused by viruses and intracellular bacteria.

Utilization of SUMO Tag and Freeze-thawing Method for a High-level Expression and Solubilization of Recombinant Human Angiotensinconverting Enzyme 2 (rhACE2) Protein in E. coli.

BACKGROUND: SARS-CoV-2 uses angiotensin-converting enzyme 2 (ACE2) as a receptor for entering the host cells. Production of the ACE2 molecule is important because of its potency to use as a blocker and therapeutic agent against SARS-CoV-2 for the prophylaxis and treatment of COVID-19. OBJECTIVE: The recombinant human ACE2 (rhACE2) is prone to form an inclusion body when expressed in the bacterial cells. METHODS: We used the SUMO tag fused to the rhACE2 molecule to increase the expression level and solubility of the fusion protein. Afterward, the freeze-thawing method plus 2 M urea solubilized aggregated proteins. Subsequently, the affinity of solubilized rhACE2 to the receptor binding domain (RBD) of the SARS-CoV-2 spike was assayed by ELISA and SPR methods. RESULTS: SUMO protein succeeded in increasing the expression level but not solubilization of the fusion protein. The freeze-thawing method could solubilize and recover the aggregated fusion proteins significantly. Also, ELISA and SPR assays confirmed the interaction between solubilized rhACE2 and RBD with high affinity. CONCLUSION: The SUMO tag and freeze- Conclusion: The SUMO tag and freeze-thawing method would be utilized for high-level expression and solubilization of recombinant rhACE2 protein.

Improving the Solubilization and Bioavailability of Arbidol Hydrochloride by the Preparation of Binary and Ternary ß-Cyclodextrin Complexes with Poloxamer 188.

In the current study, the effect of poloxamer 188 on the complexation efficiency and dissolution of arbidol hydrochloride (ADL), a broad-spectrum antiviral agent, with ß-cyclodextrin (ß-CD) was investigated. Phase solubility studies confirmed a stoichiometry of a 1:1 ratio for both ADL:ß-CD and ADL/ß-CD with a 1% poloxamer 188 system with an AL type of phase solubility curve. The stability constants (K1:1) calculated from the AL type diagram were 550 M-1 and 2134 M-1 for AD:ß-CD and ADL/ß-CD with 1% poloxamer 188, respectively. The binary ADL/ß-CD and ternary ADL/ß-CD with 1% poloxamer 188 complexes were prepared by kneading and a solvent evaporation method and were characterized by aqueous solubility, FTIR, PXRD, DSC and SEM in vitro studies. The solubility (13.1 fold) and release of ADL were markedly improved in kneaded ternary ADL/ß-CD with 1% poloxamer 188 (KDB). The binding affinity of ADL and ß-CD was confirmed by 1H NMR and 2D ROSEY studies. The ternary complex (KDB) was further subjected for in vivo pharmacokinetic studies in rats and a significant improvement in the bioavailability (2.17 fold) was observed in comparison with pure ADL. Therefore, it can be concluded that the solubilization and bioavailability of ADL can be remarkably increased by ADL/ß-CD complexation in the presence of a third component, poloxamer 188.

Sulfobutylether-beta-cyclodextrin-enabled antiviral remdesivir: Characterization of electrospun- and lyophilized formulations.

Veklury™ by Gilead Sciences, Inc., containing antiviral drug, remdesivir (REM) has received emergency authorization in the USA and in Europe for COVID-19 therapy. Here, for the first time, we describe details of the non-covalent, host-guest type interaction between REM and the solubilizing excipient, sulfobutylether-beta-cyclodextrin (SBECD) that results in significant solubility enhancement. Complete amorphousness of the cyclodextrin-enabled REM formulation was demonstrated by X-ray diffraction, thermal analysis, Raman chemical mapping and electron microscopy/energy dispersive spectroscopy. The use of solubilizing carbohydrate resulted in a 300-fold improvement of the aqueous solubility of REM, and enhanced dissolution rate of the drug enabling the preparation of stable infusion solutions for therapy. 2D ROESY NMR spectroscopy provided information on the nature of REM-excipient interaction and indicated the presence of inclusion phenomenon and the electrostatic attraction between anionic SBECD and nitrogen-containing REM in aqueous solution.