COVID-19 (Coronavirus disease 2019) is a transmissible disease initiated and propagated through a new virus strain SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus-2) since 31^st December 2019 in Wuhan city of China and the infection has outspread globally influencing millions of people. Here, an attempt was made to recognize natural phytochemicals from medicinal plants, in order to reutilize them against COVID-19 by the virtue of molecular docking and molecular dynamics (MD) simulation study. Molecular docking study showed six probable inhibitors against SARS-CoV-2 M^pro (Main protease), two from Withania somnifera (Ashwagandha) (Withanoside V [10.32 kcal/mol] and Somniferine [9.62 kcal/mol]), one from Tinospora cordifolia (Giloy) (Tinocordiside [8.10 kcal/mol]) and three from Ocimum sanctum (Tulsi) (Vicenin [8.97 kcal/mol], Isorientin 4′-O-glucoside 2″-O-p-hydroxybenzoagte [8.55 kcal/mol] and Ursolic acid [8.52 kcal/mol]). ADMET profile prediction showed that the best docked phytochemicals from present work were safe and possesses drug-like properties. Further MD simulation study was performed to assess the constancy of docked complexes and found stable. Hence from present study it could be suggested that active phytochemicals from medicinal plants could potentially inhibit M^pro of SARS-CoV-2 and further equip the management strategy against COVID-19-a global contagion. Communicated by Ramaswamy H. Sarma

Metal organic frameworks (MOFs) exhibit unique features of finely tunable pore structures, excellent chemical stability and flexible surface structural functionality, making them advantageous for a wide range of applications including energy storage, compound separation, catalysis, and drug delivery. The present work enlightens a novel approach of single step fabrication of CCM-ZIF-8 as a drug carrier and its application as stimuli responsive drug delivery systems via external stimuli involving change in pH and in presence of biomimetic cell membrane like environment using liposomes and SDS micelles. The methodology is devoid of any post synthesis drug loading steps. The synthesized curcumin encapsulated ZIF-8 frameworks demonstrate ultrahigh drug encapsulation efficiency (ca. 83.33%) and good chemical stability. In vitro drug release of curcumin was three times higher in acidic medium than in physiological pH. Cytotoxicity results demonstrated enhanced therapeutic effect of CCM-ZIF-8 than free curcumin. Confocal microscopy results confirmed the easy cellular internalization of CCM-ZIF-8 in HeLa cells. Intracellular distribution studies at various incubation times confirmed the clathrin-mediated endocytosis to lysosomal pathway of CCM-ZIF-8, but without mitochondria being an intracellular fate. The results signify that CCM-ZIF-8 is an efficient drug carrier for passive tumor therapy in future for cancer treatments.

Advanced oxidation processes (AOPs) including heterogeneous photocatalysis has proven as one of the best technique for waste-water treatment. Photocatalytic process using semiconductor like TiO₂ based heterogeneous photocatalysis is a promising method for the treatment of toxic pollutants. In the present study, visible-light photoactive cobalt and nitrogen co-doped TiO₂ nanoparticles were synthesized via wet impregnation method. The photocatalysts were characterized using X-ray diffraction (XRD), Raman Spectra, Fourier Transform Infrared (FTIR) Spectroscopy, Scanning Electron Microscopy (SEM), Transmission Electron Microscope (TEM), UV-vis spectrophotometer and X-ray photoelectron spectrophotometer (XPS). The photocatalytic activitiy of prepared (N, Co)-codoped TiO₂ on the mineralization of Bisphenol-A (BPA) under visible light irradiation was studied and the results were compared to commercial TiO₂ (Degussa P25). The results demonstrated that 1.5% Co and 0.5% N – codoped TiO₂ samples revealed higher activity than commercial TiO₂. Total organic carbon (TOC) removal was observed to be 97%, which indicate the complete mineralization of BPA. GC-MS analysis was carried to find out the possible intermediates formed and reaction pathway.

Non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (IBP) are among the most prescribed drugs across the globe. However, most NSAIDs are insoluble in water leading them to have poor bioavailability and erratic absorption. Moreover, NSAIDs such as IBP and ketoprofen (KP) have to be administered very frequently due to their short plasma half-life leading to side effects. Controlled release formulations of IBP, KP and nabumetone (NBT) based on solid lipid nanoparticles (SLNs) were successfully synthesised in the present study to solve the above-mentioned challenges that are associated with NSAIDs. SLNs were prepared in two steps; hot-melt homogenization followed by sonication to formulate SLNs with spherical morphology. While capmul® GMS-50K (capmul) was used as the lipid due to the high solubility of the studied drugs in it, gelucire® 50/13 (gelucire) was used as the surfactant. It was found that particle size was directly proportional to drug concentration and inversely proportional to surfactant concentration, volume of water added and temperature of water. Ultrasonication in a pulse mode with optimum duration of 15min was essential to obtain smaller nanoparticles through the formation of a nanoemulsion. Drug loaded SLNs with small particle size and narrow size distribution with good solid loading, encapsulation efficiency and drug loading percentage could be prepared using the optimised conditions. SLNs prepared at the optimised condition were characterized thoroughly by using different techniques such as dynamic light scattering (DLS), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). The cytotoxicity results showed that the prepared SLNs are non-toxic to Raw cell line. The drugs IBP, KP and NBT showed 53, 74 and 69% of percentage entrapment efficiency with drug loading of 6, 2 and 7% respectively. Slow, steady and sustained drug release was observed from the SLNs for over 6days.

Zika virus is a mosquito-transmitted flavivirus that causes devastating fetal outcomes in the context of maternal infection during pregnancy. An important target for drugs combatting Zika virus pathogenicity is NS2B-NS3 protease, which plays an essential role in hydrolysis and maturation of the flavivirus polyprotein. We identify hydroxychloroquine, a drug that already has approved uses in pregnancy, as a possible inhibitor of NS2B-NS3 protease by using a Food and Drug Administration-approved drug library, molecular docking, and molecular dynamics simulations. Further, to gain insight into its inhibitory potential toward NS2B-NS3 protease, we performed enzyme kinetic studies, which revealed that hydroxychloroquine inhibits protease activity with an inhibition constant (K_i) of 92.34 ± 11.91 μM. Additionally, hydroxychloroquine significantly decreases Zika virus infection in placental cells.