Targeted Gene Delivery via PEI Complexed with an Antibody

Stable carriers are required for gene delivery. The use of polyethyleneimine (PEI) has been researched extensively; however, it is not suitable for targeted gene delivery to specific cells. To provide a targeting ability of the specific antibody to PEI, two repeats of Fc-binding domain of protein G (C2) were utilized. The constructed protein containing C2 could bind to a specific antibody and form a larger complex with plasmid DNA/PEI complex. The specific antibody to cell surface protein was bound to the complex through the use of C2 domain, and it was added to cells. As the result, the efficient expression of delivered reporter gene could be realized.     

Surface characteristics of low-density polyethylene films modified by oxyfluorination-assisted graft polymerization

In this study, a unique two-step process, i.e., an oxyfluorination-assisted graft polymerization (OAGP), was used to modify the surface properties of low-density polyethylene (LDPE) films. Based on the results of the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method, which was performed to estimate the amount of hydroperoxides generated by oxyfluorination, oxyfluorination conditions that maximize the amount of hydroperoxide groups were selected. Hydroperoxides were generated by oxyfluorination to provide active sites for the OAGP of the different monomers. Depending on the type of monomers used, two different graft polymerization behaviors were observed. Hydrophilic methacrylic acid (MA) monomers were graft polymerized onto the oxyfluorinated LDPE (OFPE) surface in a perpendicular direction, forming a spike-shaped morphology. On the other hand, hydrophobic styrene (ST) monomers were graft polymerized parallel to the OFPE surface, forming a valley-shaped morphology. By changing the type of vinyl monomers, two different surfaces could be prepared using the hydroperoxides generated by oxyfluorination. After OAGP with MA monomers, a hydrophilic surface following the Wenzel model was obtained, whereas after OAGP with ST monomers, a hydrophobic surface following the Cassie–Baxter model was obtained. Therefore, the OAGP process may be an efficient method for preparing two different surfaces by changing the monomer used.     

Angelica gigas NAKAI and Its Active Compound,Decursin, Inhibit Cellular Injury as an Antioxidant by the Regulation of AMP-Activated Protein Kinase and YAP Signaling

Natural products and medicinal herbs have been used to treat various human diseases by regulating cellular functions and metabolic pathways. Angelica gigas NAKAI (AG) helps regulate pathological processes in some medical fields, including gastroenterology, gynecology, and neuropsychiatry. Although some papers have reported its diverse indications, the effects of AG against arachidonic acid (AA)+ iron and carbon tetrachloride (CCl₄) have not been reported. In HepG2 cells, AA+ iron induced cellular apoptosis and mitochondrial damage, as assessed by mitochondrial membrane permeability (MMP) and the expression of apoptosis-related proteins. On the other hand, AG markedly inhibited these detrimental phenomena and reactive oxygen species (ROS) production induced by AA+ iron. AG activated the liver kinase B1 (LKB1)-dependent AMP-activated protein kinase (AMPK), which affected oxidative stress in the cells. Moreover, AG also regulated the expression of yes-associated protein (YAP) signaling as mediated by the AMPK pathways. In mice, an oral treatment of AG protected against liver toxicity induced by CCl₄, as indicated by the plasma and histochemical parameters. Among the compounds in AG, decursin had antioxidant activity and affected the AMPK pathway. In conclusion, AG has antioxidant effects in vivo and in vitro, indicating that natural products such as AG could be potential candidate for the nutraceuticals to treat various disorders by regulating mitochondrial dysfunction and cellular metabolic pathways.     

A new copolymerization process leading to poly(propylene carbonate) with a highly enhanced yield from carbon dioxide and propylene oxide

Using excessively loaded propylene oxide (PO) as a solvent, the copolymerization of carbon dioxide (CO₂) and PO was carried out with zinc glutarate catalyst, consequently producing poly(propylene carbonate) of high molecular weight in a high yield (64–70 g polymer per gram of catalyst) never achieved before. Both the PO used as solvent and the excessively loaded CO₂ were fully recoverable, respectively, and reusable for their copolymerization, indicating that this is a clean, green polymerization process to convert CO₂ to its polycarbonate. The polymer yield was further improved by scaling up the copolymerization process. Among zinc glutarate catalysts prepared through several synthetic routes, one from zinc oxide delivered the highest yield in the copolymerization. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1863–1876, 1999