Whey protein microgel particles as stabilizers of waxy corn starch + locust bean gum water-in-water emulsions

Food-grade whey protein isolate (WPI) microgel particles were investigated as a particle stabilizer of water-in-water (W/W) emulsions. The microgel particles were produced via the novel method of forcing coarse particles of a pre-formed thermally processed WPI protein gel through a jet homogenizer. The Z-average particle size was 149 ± 89 nm but the particles showed a strong tendency for aggregation when the pH was lowered from pH 7 to 4, when the zeta potential also switched from -17 to +12 mV. The viscoelasticity of suspensions of the particles, measured between 1 and 15 vol.% (0.02 and 3 wt.%) increased with concentration and was also higher at pH 4 than pH 7. However, all the suspensions were only weakly shear thinning, suggesting that they did not form very strong networks. The particles were added (at 1-15 vol.%) to a model W/W system consisting of waxy corn starch (S) + locust bean gum (LBG) that normally shows phase separation when the components are mixed at 90 °C then cooled to room temperature (22-25 °C). At 10 to 15 vol.% particles and pH 4, visual observation showed striking inhibition of phase separation, for a period of up to 1 year. Confocal laser scanning microscopy suggested that under these conditions extensive aggregation of the microparticles occurred within the starch phase but also possibly at the W/W interface between the starch-rich and gum-rich regions, supporting a Pickering-type mechanism as responsible for the enhanced stabilization of the W/W emulsion by the microgel particles

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

Bioreactors as engineering support to treat cardiac muscle and vascular disease

Cardiovascular disease is the leading cause of morbidity and mortality in the Western World. The inability of fully differentiated, load-bearing cardiovascular tissues to in vivo regenerate and the limitations of the current treatment therapies greatly motivate the efforts of cardiovascular tissue engineering to become an effective clinical strategy for injured heart and vessels. For the effective production of organized and functional cardiovascular engineered constructs in vitro, a suitable dynamic environment is essential, and can be achieved and maintained within bioreactors. Bioreactors are technological devices that, while monitoring and controlling the culture environment and stimulating the construct, attempt to mimic the physiological milieu. In this study, a review of the current state of the art of bioreactor solutions for cardiovascular tissue engineering is presented, with emphasis on bioreactors and biophysical stimuli adopted for investigating the mechanisms influencing cardiovascular tissue development, and for eventually generating suitable cardiovascular tissue replacements

68Ge/68Ga radioisotope generator as a source of radiotracers for water flow investigations

Radiotracer experiments on the model of rectangular settler with a volume of 3 m3, with a consecutive application as a tracer of the aqueous phase fluoresceine (representative tracer of water), eluate from a 68Ge/68Ga radioisotope generator (0.1 N HCl solution) and chelates after Ga ions complexation with 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA) and 1,4,7,10-tetrazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) were carried out. The obtained residence time distribution (RTD) functions indicate that only the complex compounds of gallium are stable in the water phase and are not adsorb on the vessel walls, so they can be recommended as tracers of the water phase

Optimization of mixer-distributor parameters with the application of tracer and CFD methods

Przedstawiono komplementarne zastosowanie metod znacznikowych i CFD do opisu i optymalizacji parametrów pracy mieszacza/dystrybu-tora ścieków z różnych źródeł uśredniającego ich skład chemiczn

Stable isotope deuterium as a natural tracer of mixing processes in rivers

The possibility of application of naturally existing differences in isotope contents 18O/16O, 2H/1H in waters for investigation of transport and mixing of various waters in the tributary-river system is presented. Experiments carried out on the Bug-Narew rivers-Zegrze Lake and the BugoNarew-Vistula rivers systems have indicated that the hydrogen isotope ratio 2H/1H can be used as an intrinsic tracer of natural mixing processes occurring in rivers. The IRMS methodology was used for isotope ratio measurement of water samples. The degrees of water mixing as a function of distance from the confluence point of rivers were determined. The obtained results indicate that in water systems where the natural differences in ?2H are higher than 5‰ this technique can replace the time-consuming and expensive dye (or radiotracer) dispersion tests for evaluation of pollutant transport in rivers