Development of adenovirus immobilization strategies for in situ gene therapy

Background Regenerative gene therapy using viral vectors enables transduced cells to express bioactive factors in vivo . Viral delivery with spatial control can enhance transduction efficiency and may limit systemic infection. Consequently, we tethered biotinylated adenovirus via interactions with avidin on chitosan surfaces to gain robust control for in situ transduction. Methods Avidin was either directly conjugated to chitosan (virus–biotin–avidin-material; VBAM) or indirectly docked on biotinylated chitosan surfaces (virus–biotin–avidin–biotin-material; VBABM) to tether biotinylated adenovirus. Enzyme-linked immunosorbent assay (ELISA) and spectroscopic analysis were performed to demonstrate the binding profiles. Biotin-alkaline phosphatase and biotinylated adenovirus were used as different sized particles to evaluate binding efficiencies and were compared by the Sips isotherm adsorption method. Scanning electron microscopy (SEM) examination illustrated virus distribution, and the transduction efficiency was determined by in vitro cell transduction. Results ELISA and spectroscopic analysis both demonstrated that the VBAM system led to multilayer avidin formation on biomaterial surfaces, whereas VBABM formed a monolayer of avidin. Sips isotherm adsorption indicated that the VBAM method increased heterogeneity and steric hindrance of binding sites. By contrast, the VBABM method docked avidin on chitosan surfaces and orientated the binding sites to facilitate ligand binding. In addition, SEM images illustrated that the VBABM method led to more even viral distribution. In vitro cell infection experiments also demonstrated that the VBABM system enhanced virus immobilization and thus improved cell transduction efficiency over the VBAM system. Conclusions The VBABM strategy is a superior method for in situ transduction from biomaterials. This strategy could be adapted for use with a variety of biomaterials as well as viral vectors, and thus may be an alternative method for in vivo regenerative gene therapy. Copyright © 2008 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/60964/1/1233_ftp.pd

A review of soil NO transformation: associated processes and possible physiological significance on organisms

NO emissions from soils and ecosystems are of outstanding importance for atmospheric chemistry. Here we review the current knowledge on processes involved in the formation and consumption of NO in soils, the importance of NO for the physiological functioning of different organisms, and for inter- and intra-species signaling and competition, e.g. in the rooting zone between microbes and plants. We also show that prokaryotes and eukaryotes are able to produce NO by multiple pathways and that unspecific enzymo-oxidative mechanisms of NO production are likely to occur in soils. Nitric oxide production in soils is not only linked to NO production by nitrifying and denitrifying microorganisms, but also linked to extracellular enzymes from a wide range of microorganisms. Further investigations are needed to clarify molecular mechanisms of NO production and consumption, its controlling factors, and the significance of NO as a regulator for microbial, animal and plant processes. Such process understanding is required to elucidate the importance of soils as sources (and sinks) for atmospheric NO

Identification of Saccharomyces Cerevisiae YPR1 as a Methylglyoxal Reducing Enzyme: Over-Expression Enhances Oxidative Stress Tolerance in E. Coli

Methylglyoxal, generated from the triosephosphates of glycolysis, is a toxic electrophile that can modify proteins and nucleic acids and cause oxidative stress in cells, consequently causes dysfunction of cells and tissues. Its levels increase in many pathological conditions in humans and, in plants, when under environmental stress. Aiming to look for new enzymes to detoxify methylglyoxal and utilize these enzymes to protect plants against environmental stress, we identified Saccharomyces cerevisiae YPR1 as a methylglyoxal reducing enzyme. By four steps of partial purification, we located a few protein candidates on a SDS-PAGE gel. The genes encoding these proteins were identified by mass spectrometry MALDI-TOF. By excluding those genes with known functions, the most possible gene YPR1 was selected to express in E. coli. Protein crude extract of YPR1 expressing E. coli had about 120-fold increase in methylglyoxal reducing activity compared to the control strain. Tolerance of the YPR1 expressing E. coli against oxidative stress was improved. The results demonstrate that yeast YPR1 has the potential to enhance environmental stress tolerance of plants and other organisms

Stabilization of sunflower oil with pussy willow (Salix aegyptiaca) extract and essential oil

The aim of present study was to evaluate antioxidant efficacy of pussy willow extract (PWE) and essential oil (PWEO) in stabilization of sunflower oil (SFO) during ambient storage (60 days at 25°C). Initially, total phenolic (TP) and total flavonoid (TF) contents were evaluated. Then, PWE, PWEO, and TBHQ were added to SFO. Peroxide value (PV), carbonyl value (CV), total polar compound (TPC), acid value (AV), and Oxidative stability index (OSI) were measured every 15 days. The results showed that PWE had higher TP and TF than PWEO (TP: 966.72 mg GAE/g and 355.8472 mg GAE/g, respectively; TF: 619.45 mg/100 g and 195.45 mg/100 g, respectively). Furthermore, according to all stabilization parameters, PWE had higher antioxidant efficacy followed by TBHQ, PWEO, and control, respectively. Therefore, PWE has antioxidant activity and it may be recommended as natural strong antioxidants to suppress lipid oxidation