The use of liposome encapsulated tetracycline significantly improved STT and TBUT values as well as reverse surface ocular pathology.

The main aim of the work was the fabrication of novel silver releasing nanocomposite scaffolds, for bone treatment, by the gas foaming/particulate-leaching technique. Silver doped bioactive glass nanoparticles were used as a filler, to provide the scaffolds with bioactivity, as well as anti-bacterial properties. Nanocomposite scaffolds containing 0, 20 and 40 wt% glass contents were prepared and coded as PAg0, PAg20 and PAg40, respectively. The scaffolds were characterized by SEM/EDXA, FTIR and TGA. Examination of SEM microphotographs showed that, the produced scaffolds had well interconnected structures. For PAg0, PAg20 and PAg40, the maximum pore sizes were about 250, 150 and 100 lm, respectively, while their porosities % were 92%, 89% and 83%, respectively. Degradation studies were carried out, by incubating the scaffolds in simulated body fluid, for a month. Results revealed the possibility to modulate and improve the degradation of the scaffolds by increasing their glass contents. The final weight losses measured for PAg0, PAg20 and PAg40 were 12.76%, 14.61% and 17.42%, respectively. On the other hand, the highest water absorption values recorded for those scaffolds were 61.89%, 240.36% and 270.87%, respectively, indicating that, the addition of glass nanoparticles to the scaffolds improved their water absorption abilities. Both PAg20 and PAg40 induced an apatite layer on their surfaces, had

The interaction between doxorubicin (DOX), an anthracycline antibiotic frequently used in chemotherapy, and zwitterionic dipalmitoylphosphatidylcholine (DPPC) was investigated using Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), and rheological measurements. FTIR results showed that DOX shifted the wavenumber of the PO(2)(-) band for pure DPPC to a higher wavenumber. This may have been because of the strong interactions between the NH(3)(+) group in DOX and the phosphate (PO(2)(-)) group in the polar head of DPPC. The main transition temperature of DPPC liposomes was slightly shifted to a lower temperature for DPPC liposome-encapsulated DOX. This suggested that DOX had a significant effect on the acyl chains in the DPPC bilayers, and that its presence decreased the transition cooperativity of lipid acyl chains. There was also the appearance of an additional transition peak at nearly 136 °C for the DPPC/DOX sample. These interactions between DOX and DPPC phospholipid would cause a decrease in the DPPC liposomes plastic viscosity and increase membrane fluidity. A better understanding of the interactions between DOX and lipid bilayers could help in the design and development of improved liposomal drug delivery systems.

This study demonstrated that G. biloba, through its free radical scavenging and antioxidant properties, successfully attenuated Tc-sestamibi radiation-induced oxidative organ injury. The latter is a crucial factor of cataractogenesis in rats, suggesting that G. biloba may have a potential benefit in the protection against radiopharmaceuticals.

Coronavirus diseases 2019 (COVID-19) are seriously affecting human health all over the world. Nucleotide inhibitors have promising results in terms of its efficacy against different viral polymerases. In this study, detailed molecular docking and dynamics simulations are used to evaluate the binding affinity of a clinically approved drug, sofosbuvir, with the solved structure of the viral protein RNA-dependent RNA polymerase (RdRp) and compare it to the clinically approved drug, Remdesivir. These drugs are docked onto the three-dimensional structure of the nsp12 protein of SARS-CoV-2, which controls the polymerization process. Hence, it is considered one of the primary therapeutic targets for coronaviruses. Sofosbuvir is a drug that is currently used for HCV treatment; therefore, HCV RdRp is used as a positive control protein target. The protein dynamics are simulated for 100 ns, while the binding is tested during different dynamics states of the SARS-CoV-2 RdRp. Additionally, the drug-protein complexes are further simulated for 20 ns to explore the binding mechanism. The interaction of SARS-CoV-2 RdRp as a target with the active form of sofosbuvir as a ligand demonstrates binding effectiveness. One of the FDA-approved antiviral drugs, such as sofosbuvir, can help us in this mission, aiming to limit the danger of COVID-19. Sofosbuvir was found to bind nsp12 with comparable binding energies to that of Remdesivir, which has been reported for its potential against COVID-19 RdRp and is currently approved by the FDA.

No abstract

The incorporation efficiencies of lutein, zeaxanthin, canthaxanthin and beta-carotene into Retinal Pigment Epithelial (RPE) cells (the human RPE cell line D 407), liver microsomes and EYPC liposomes are investigated. In RPE cells the efficiency ratio of lutein and zeaxanthin compared to canthaxanthin and beta-carotene is higher than in the other membranes. The preferential interactions of lutein and zeaxanthin with RPE cells are discussed considering special protein binding properties. Incorporation yields were obtained from the UV-Vis spectra of the carotenoids. Membrane modulating effects of the carotenoids were obtained from the fluorescence spectra of co-incorporated Laurdan (6-dodecanoyl-2-dimethylaminonaphtalene). The Laurdan fluorescence quenching efficiencies of the membrane bound carotenoids offer an access to direct determinations of membrane carotenoid concentrations. Fetal calf serum as carrier for carotenoid incorporation appears superior to tetrahydrofuran.

The interactions between carotenoids and membrane constituents are vital for understanding the mechanism of their dynamic action.