Adult Cardiac Progenitor Cell Aggregates Exhibit Survival Benefit Both In Vitro and In Vivo

Background: A major hurdle in the use of exogenous stems cells for therapeutic regeneration of injured myocardium remains the poor survival of implanted cells. To date, the delivery of stem cells into myocardium has largely focused on implantation of cell suspensions. Methodology and Principal Findings: We hypothesize that delivering progenitor cells in an aggregate form would serve to mimic the endogenous state with proper cell-cell contact, and may aid the survival of implanted cells. Microwell methodologies allow for the culture of homogenous 3D cell aggregates, thereby allowing cell-cell contact. In this study, we find that the culture of cardiac progenitor cells in a 3D cell aggregate augments cell survival and protects against cellular toxins and stressors, including hydrogen peroxide and anoxia/reoxygenation induced cell death. Moreover, using a murine model of cardiac ischemia-reperfusion injury, we find that delivery of cardiac progenitor cells in the form of 3D aggregates improved in vivo survival of implanted cells. Conclusion: Collectively, our data support the notion that growth in 3D cellular systems and maintenance of cell-cell contact improves exogenous cell survival following delivery into myocardium. These approaches may serve as a strategy to improve cardiovascular cell-based therapies

Retarding aging of asphalt binders using antioxidant additives and copolymers

The rheological properties of asphalt binders change with aging. Aging is accelerated at elevated temperatures due to binder oxidation, leading to fatigue cracking and eventually pavement failure under heavy and repeated traffic loading. This study examined the effect of various antioxidant additives and copolymers with antioxidant agents on retarding the aging of asphalt binders. The performance of antioxidants was evaluated at the binder and mastic levels. Two unmodified binders were tested and fine asphalt mixtures made with these binders and three different aggregates were prepared and evaluated. Fatigue characteristics of asphalt binders and fine portion of asphalt mixtures (FAM) were determined before and after aging and an aging index was defined to evaluate the effect of antioxidants�and copolymers on aging. The results showed that certain antioxidants�and copolymers such as Redicote AP, Solprene and Calprene may retard the aging and improve the rheological properties of the asphalt binders. In addition, the results of FAM testing confirmed the favourable effect of certain antioxidants on improving the resistance to fatigue. In addition, the type of aggregate was found to influence the rate of aging of asphalt mixtures. - 2017, - 2017 Informa UK Limited, trading as Taylor & Francis Group.This work was supported by Qatar National Research Fund [grant number NPRP 6-773-2-320]. This paper was made possible by the NPRP grant (NPRP 6-773-2-320) from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors.Scopu

Extender Supplementation with Glutathione (GSH) and Taurine Improves In Vitro Sperm Quality and Antioxidant Status of New Zealand Rabbits during Chilled Storage for up to 72 hours

This study assessed the influence of supplementing the rabbit semen extender with various concentrations of glutathione (GSH) and taurine at 24, 48, and 72 h postchilling at 5°C. Semen samples were collected from 20 New Zealand bucks, and ejaculates with standard color, motility (>85%), about 0.5 mL volume, and ∼400 × 106/mL concentration were used and diluted with extenders supplemented with 0.5, 1, and 2 mM of GSH and 1, 5, and 10 mM of taurine and chilled at 5°C. Nonsupplemented samples were used as a control. Sperm’s progressive motility, acrosome reaction, and extracellular oxidative stress biomarkers such as MDA contents and GPx, SOD, and CAT concentrations and intracellular transcriptomic levels of SOD and CAT genes were assessed. GSH and taurine supplementation improved the sperm’s kinetics by reducing cooling-associated stress, which was ascertained by lowering MDA concentration and increasing SOD, CAT, and GPx concentrations (P < 0.05). Increasing the levels of antioxidant enzymes in the extender was due to the increasing mRNA copies of the SOD and CAT genes (P < 0.05). Furthermore, GSH and taurine maintained the fructose levels in the extender and lowered the GPT levels, which implies sperm membrane stability is maintained through GSH and taurine supplementation. GSH and taurine supplementation to the extender had protective influences on the in vitro rabbit semen quality during chilled storage for up to 72 h, which were remarkable with increasing supplementation dose and cooling time at 5°C