Due to its low bioavailability and slow dissolution rate, the micronized spiramycin powder was thus prepared by the homogenate-antisolvent precipitation (HAP) process. The optimum micronization conditions of the HAP process were found to be as follows: precipitation temperature of 4.6 °C, precipitation time of 10 min, spiramycin concentration of 20 mg/mL, dripping speed of the added solvent into the antisolvent of 44 mL/h, antisolvent (water) to solvent (dimethyl sulfide (DMSO)) volume ratio of 7:1, and shear rate of 5000 rpm. With this HAP process, the mean particle size was 228.36 ± 3.99 nm. The micronized spiramycin was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, high-performance liquid chromatography, and gas chromatograph analyses. In comparison with the raw drug, the chemical structure of micronized spiramycin was not changed. The dissolution rate experiments showed that the dissolution rate of the spiramycin was significantly increased after micronization. Full article

A combination of far-field electrospinning (FFES) and free-radical polymerization has been used to fabricate coated electrospun polymer fiber mats as a new type of biosensor platform. Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) electrospun fibers were dip-coated with different compositions of poly methyl methacrylate-co-methacrylic acid (poly(MMA-co-MAA)). This synergistic approach utilizes large specific surface area of PHBV fibers and co-polymer coatings that feature an optimum concentration of surface carboxyl (–COOH) groups. The platform surface morphology, porosity and tunable hydrophobicity enhance biomolecular interactions via plurality of molecular forces. These customized fiber mats have been integrated into a newly designed 96-well plate called an “intrant enzyme-linked immunosorbent assay” or i-ELISA. I-ELISA allows colorimetric sandwich assay to be carried out without any modifications or additional steps in ELISA methodology. By introducing the fiber mats in fabrication of i-ELISA via extensions on the lid, we address some of the limitations of the previous designs while demonstrating an enhanced signal intensity up to 12 times higher than that of conventional assays. With improved sensitivity, specificity and accuracy in the detection of dengue virus, i-ELISA has proven to be a reliable platform for biomolecular recognition. The proposed fiber mat-assisted well plate in this study holds great potential as a universal approach for integration of different types of fiber mats with pre-designed specific properties in order to enhance the detection sensitivity of the assay. Full article

Helicobacter pylori is a spiral-shaped bacterium that grows in the human digestive tract; it infects ~50% of the global population. H. pylori induce inflammation, gastroenteritis, and ulcers, which is associated with significant morbidity and may be linked to stomach cancer in certain individuals. Motility is an essential virulence factor for H. pylori, allowing it to migrate toward and invade the epithelial lining of the stomach to shelter it from the harsh environment of the stomach. H. pylori senses pH gradients and use polar flagella to move towards the epithelium where the pH approaches neutrality. However, its chemotaxis behaviors are incompletely understood. Previous in vitro tests examining the response of H. pylori to chemical gradients have been subjected to substantial limitations. To more accurately mimic/modulate the cellular microenvironment, a nanoporous microfluidic device was used to monitor the real time chemotactic activity of single cell of H. pylori in response to urea. The results showed that microfluidic method is a promising alternative for accurate studying of chemotactic behavior of H. pylori, the application of which may also be extended in the studies of other bacteria. Full article