Dynamics of Microbial Shedding in Market Pigs during Fasting and the Influence of Alginate Hydrogel Bead Supplementation during Transportation

The shedding of foodborne pathogenic bacteria by food-animals can be affected by multiple factors, such as animal health, diet, stress, and environmental conditions. The practices that come with transport involve fasting, handling, mixing with unfamiliar pigs, and fluctuating temperatures. These practices, especially fasting and transport, can increase the microbial load in the feces of animals. The use of alginate hydrogels is a novel delivery system that can be a potential food safety intervention during transport to induce satiety and provide electrolytes to the animal’s system. This study sought to observe microbial shedding as affected by fasting and hydrogel bead supplementation during transport. Sixty market pigs were subjected to a 12 h fasting period and an additional 4 h transport period, in which a treatment group was fed hydrogel beads and a control group was not. Sampling points were before fast (BF), before transport (BT), and after transport (AT). Fecal samples were collected from every animal at each sampling point. Results from this study showed a significant increase in the concentrations of both Enterobacteriaceae and Escherichia coli between the before fast (BF) and after transport (AT) sampling points. However, no difference (p > 0.05) was found between the treatment (hydrogel) and control (no hydrogel) during transport. Moreover, no significant difference was found in the prevalence of Salmonella and E. coli O157:H7 at the three different sampling points, or between the treatment and control groups.

Enhanced floating and intragastric release of 5-Flourouracil through sesame oil entrapped gellan composite hydrogel beads

Background: 5-Fluorouracil is an anti-metabolite compound used for several years as an anti-tumor drug. The development of a gastroretentive drug delivery system of 5-Fluorouracil may have advantages since they retain in the stomach for an extended time and release the drug in a sustained manner which ultimately enhances the absorption of the drug and consequently the bioavailability. Objective: The objective of the present work was to prepare a sesame oil-entrapped gellan gum hydrogel bead for controlled stomach specific delivery of 5-Fluorouracil. Methods: Sesame oil-entrapped gellan gum hydrogel bead was prepared by ionotropic gelation method. The developed hydrogels were characterized by SEM, FTIR, DSC, and XRD. The entrapment efficiency, floating ability, swelling and drug release in vitro were also determined. Results: Electrostatic interaction between the carboxylic group of polymers and Ca++ was confirmed by FTIR analysis. The SEM photograph of the hydrogel beads portrayed an approximately spherical shaped structure. DSC thermogram and XRD spectra exhibited the molecular dispersion of the drug inside the hydrogel beads. The developed beads of 5-Fluorouracil floated in pH 1.2 buffer solutions for a prolonged time period and the duration of floating was improved significantly with increasing the concentration of oil. The developed formulations showed controlled release of drug and incorporation of oil retarded the release of the drug. Fickian and non-Fickian mechanism of drug transport was observed from the prepared hydrogel beads. Conclusion: Overall, the oil-entrapped gellan matrices could be used for the intragastric delivery of 5-Fluorouracil to treat stomach cancer.

A Lipid Bilayer Formed on a Hydrogel Bead for Single Ion Channel Recordings

Ion channel proteins play important roles in various cell functions, making them attractive drug targets. Artificial lipid bilayer recording is a technique used to measure the ion transport activities of channel proteins with high sensitivity and accuracy. However, the measurement efficiency is low. In order to improve the efficiency, we developed a method that allows us to form bilayers on a hydrogel bead and record channel currents promptly. We tested our system by measuring the activities of various types of channels, including gramicidin, alamethicin, α-hemolysin, a voltage-dependent anion channel 1 (VDAC1), a voltage- and calcium-activated large conductance potassium channel (BK channel), and a potassium channel from Streptomyces lividans (KcsA channel). We confirmed the ability for enhanced measurement efficiency and measurement system miniaturizion.

Application of Photocatalytic and Adsorption Process for Residue Organic Degradation Using Doped ZnO Composites Hydrogel Beads

This research aimes to synthesize photocatalyst-sodium alginate composite hydrogel beads which apply for coupled adsorption and photocatalytic degradation of organic residue. Fe3O4, graphitic carbon nitride (g-C3N4), grapheme oxide (GO) and AgNO3 doped ZnO photocatalyst composites hydrogel beads were synthesized and characterized using Fourier-transform infrared spectroscopy (FT-IR), X-ray Diffraction (XRD), and Transmission Electron Microscopy (TEM). Photocatalytic and adsorption activity are studied by Methylene blue (MB) degradation under sunshine irradiation. The effect of different parameter as photocatalyst types and reaction time were studied upon the efficiency of organic residue degradation. The coupled photocatalytic and adsorption processes were evaluated through various kinetic models such as pseudo-first-order/ pseudo-second-order in Langmuir-Hinshelwood model model, the Elovich model and the intra particle diffusion model. Kinetics studies showed that the coupled photocatalytic and adsorption processes in photodegradation of all sample was well described by the pseudo-second-order model because R2 of all sample were close to 1 which compared with another model. For photodegradation efficiency, the best choice in this condition was g-C3N4 doped ZnO composite hydrogel bead. Photodegradation efficiency and the pseudo second order rate constant of photocatalyst ZnO+gC3N4/SA composite hydrogel bead were 83.80%(for 180 min and up to 96% for 7 hr) and 5.05×10-3 g.mg-1 min-1, respectively.