COVID-19 reinfection in a healthcare worker after exposure with high dose of virus: A case report.

Reinfection with COVID-19 is possible after exposure to a high dose of the virus. Due to immunity acquired during the previous infection, light symptoms are expected. The finding indicates importance of continuous protection in healthcare workers.

Sensitization of A-549 lung cancer cells to Cisplatin by Quinacrine-loaded lipidic nanoparticles via suppressing Nrf2 mediated defense mechanism.

Nuclear factor erythroid 2-related factor 2 (Nrf2) is believed to be responsible for the control mechanisms of cellular defense response and master regulator of antioxidant system by adjustment of endogenous antioxidants, phase II detoxifying enzymes and transporters, so inhibition of Nrf2 could be considered molecule target to overcome drug resistance and cancer progression. By harnessing liposome as an advanced nanoparticles transporter, we formulated Quinacrine known as nrf2 inhibitor into nano-carrier, and sensitized A-549 lung tumor cells to Cisplatin. The aim of this work was to prepare liposome nano-carriers to enhance the bioavailability of Quinacrine and to improve passive targeting in A549 cells. Quinacrine formulation into liposome exposed a mean particle size of 80±5 nm in passive targeting and 110±3 after decoration with chitosan oligosaccharides (COS), respectively. The highest amount of cell death (p<0.05) occurred with the co-incubation of the A549 cells with new formulation and Cisplatin. Additionally, Quinacrine-loaded liposomes declined Nrf2 expression more than Quinacrine alone (p<0.05). Correspondingly, the expression of Nrf2 downstream genes, MRP1, Trx, and bcl2 decreased significantly. Taking all the data into consideration, liposomes containing Quinacrine could ameliorate the effectiveness of Cisplatin by raising the permeability of cancer cells to the abovementioned chemical treatment and might be then given as a candidate to boost the therapeutic protocols in cancer patients.

Silver sulfadiazine-loaded electrospun ethyl cellulose/polylactic acid/collagen nanofibrous mats with antibacterial properties for wound healing.

Recently, the electrospun nanofiber mats with appropriate properties for applications in the biomedical area has been more considered. In this regard, we successfully fabricated a novel antibacterial nanofiber mat (ethyl cellulose/poly lactic acid/collagen) (EC/PLA/collagen) incorporated with silver sulfadiazine (AgSD) and then analyzed with the required tests. AgSD was loaded in the developed mats with different contents (0.25%, 0.5% and 0.75%) and then electrospun to prepare nanofiber mats. To check the chemical structure of the developed mat, Fourier transform infrared spectroscopy (FTIR) was assessed. Surface morphological studies were performed by Scanning Electron Microscopy (SEM), which displayed uniform nanofiber mats without any bead formation. When the hydrophilicity was enhanced by decreasing the blending ratios of EC/PLA, the thermal stability of the nanofibers was reduced. The water contact angle (WCA) of NFs enhanced by decreasing the blending ratios of EC/PLA. The antibacterial properties showed the inhibition activity against Bacillus (9.71 ± 1.15 mm) and E. coli (12.46 ± 1.31 mm) bacteria. Besides, nanofibers have improved cell proliferation and adhesion with any cytotoxic effect on NIH 3T3 fibroblast cells. According these results, it seems that the developed mats would be effective scaffold for application in wound dressings.

Gold Nanoprobe-Based Detection of Human Telomerase Reverse Transcriptase (hTERT) Gene Expression.

Human Telomerase Reverse Transcriptase (hTERT) gene is expressed in all types of cancers, and it is considered as unique biomarker for early detection, monitoring and prognosis of different cancers. Routinely, the main techniques for detection of hTERT gene expression are based on enzymatic amplifications which need specified equipments, expert personnel and high cost and time. With regarding to the clinical importance of analysis of hTERT gene expression, we have developed a rapid, simple and low cost method which detects hTERT RNA target in 5 µl reaction scale using gold nanoprobes. The method is based on the inhibition of nanoparticle aggregation in the presence of MgCl 2 and it can be used as a basic technique for development of clinical scale gold nanoprobe nanobiodiagnostics for detection of hTERT gene expression with a limit of detection at fmol/µl concentrations.

Amelioration by chicory seed extract of diabetes- and oleic acid-induced non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH) via modulation of PPARα and SREBP-1.

We evaluated the effect of chicory (Cichorium intybus L.) seed extract (CI) on hepatic steatosis caused by early and late stage diabetes in rats (in vivo), and induced in HepG2 cells (in vitro) by BSA-oleic acid complex (OA). Different dosages of CI (1.25, 2.5 and 5 mg/ml) were applied along with OA (1 mM) to HepG2 cells, simultaneously and non-simultaneously; and without OA to ordinary non-steatotic cells. Cellular lipid accumulation and glycerol release, and hepatic triglyceride (TG) content were measured. The expression levels of sterol regulatory element-binding protein-1c (SREBP-1c) and peroxisome proliferator-activated receptor alpha (PPARα) were determined. Liver samples were stained with hematoxylin and eosin (H&E). Significant histological damage (steatosis-inflammation-fibrosis) to the cells and tissues and down-regulation of SREBP-1c and PPARα genes that followed steatosis induction were prevented by CI in simultaneous treatment. In non-simultaneous treatment, CI up-regulated the expression of both genes and restored the normal levels of the corresponding proteins; with a greater stimulating effect on PPARα, CI acted as a PPARα agonist. CI released glycerol from HepG2 cells, and targeted the first and the second hit phases of hepatic steatosis. A preliminary attempt to characterize CI showed caffeic acid, chlorogenic acid, and chicoric acid, among the constituents.