A comparative study of single-needle and coaxial electrospun amyloid-like protein nanofibers to investigate hydrophilic drug release behavior.

In this study, nanofibers containing an amyloid-like bovine serum albumin (AL-BSA) carrier and a model drug (ampicillin) were produced by electrospinning. The release behavior of ampicillin was compared from electrospun nanofibers prepared as either coaxial or single-needle types. SEM images showed that the membranes had a uniform and smooth structure and the core/shell fibers were found to be thicker than the core fibers. Core/shell production was proved by transmission electron microscopy images. Fourier transform infrared spectroscopy indicated the existence of compatibility between ampicillin and the AL-BSA matrix. The in vitro antimicrobial properties of ampicillin were studied through the comparison of bacterial inhibition zones and ampicillin was found to be more effective against Gram-positive Staphylococcus aureus than Gram-negative Escherichia coli. Moreover, in vitro drug release tests were conducted to explore the relationship between the shell thickness and the drug release rate. A burst release was observed for all membranes owing to the small fiber diameters and thus short diffusion lengths. For core membranes, the drug release mechanism followed Fickian transport, which was close to zero-order kinetic. A typical biphasic release mechanism was observed for the core/shell nanofibers. Overall, we present the first evidence of AL-BSA as a potential core/shell drug mediator.

Surface decontamination of eggshells by using non-thermal atmospheric plasma.

In this study, the possibility of using an effective short time non-thermal plasma (NTP) treatment to inactivate Salmonella enterica serovar Enteritidis on eggshell surface was investigated. The eggshells were artificially contaminated with S. Enteritidis at an initial concentration of 107cfu/egg and then treated with an atmospheric pressure plasma jet by using air as process gas under different experimental settings with various frequencies (20-25kHz) and reference voltages (100-80%), exposure times (60-120s), distances from plasma jet (15 or 40mm) and gas flow rates (2000-3000L/h). The best result was obtained at maximum plasma power of 655W (25kHz-100% V), where S. Enteritidis concentration on egg surface was reduced below the detection limit (102cfu/egg) after 120s of treatment. The temperature remained below 35°C after all plasma treatments in order to minimize the risk of egg quality alterations. Specific measurements demonstrated that there were no negative effects on egg quality after NTP treatment. The effect of plasma process on the egg cuticle was demonstrated by using scanning electron microscopy.

Decontamination of Aspergillus flavus and Aspergillus parasiticus spores on hazelnuts via atmospheric pressure fluidized bed plasma reactor.

In this study, an atmospheric pressure fluidized bed plasma (APFBP) system was designed and its decontamination effect on aflatoxigenic fungi (Aspergillus flavus and Aspergillus parasiticus) on the surface of hazelnuts was investigated. Hazelnuts were artificially contaminated with A. flavus and A. parasiticus and then were treated with dry air plasma for up to 5min in the APFBP system at various plasma parameters. Significant reductions of 4.50 log (cfu/g) in A. flavus and 4.19 log (cfu/g) in A. parasiticus were achieved after 5min treatments at 100% V - 25kHz (655W) by using dry air as the plasma forming gas. The decontamination effect of APFBP on A. flavus and A. parasiticus spores inoculated on hazelnuts was increased with the applied reference voltage and the frequency. No change or slight reductions were observed in A. flavus and A. parasiticus load during the storage of plasma treated hazelnuts whereas on the control samples fungi continued to grow under storage conditions (30days at 25°C). Temperature change on hazelnut surfaces in the range between 35 and 90°C was monitored with a thermal camera, and it was demonstrated that the temperature increase taking place during plasma treatment did not have a lethal effect on A. flavus and A. parasiticus spores. The damage caused by APFBP treatment on Aspergillus spp. spores was also observed by scanning electron microscopy.