High internal phase emulsions have been widely used as templates for various porous materials, but special strategies are required to form, in particular, particle-covered ones that have been more difficult to obtain. Here, we report a versatile strategy to produce a stable high internal phase Pickering emulsion by exploiting a depletion interaction between an emulsion droplet and a particle using water-soluble polymers as a depletant. This attractive interaction facilitating the adsorption of particles onto the droplet interface and simultaneously suppressing desorption once adsorbed. This technique can be universally applied to nearly any kind of particle to stabilize an interface with the help of various non- or weakly adsorbing polymers as a depletant, which can be solidified to provide porous materials for many applications.

Multiscale porosity assures better mass transport for a low Pt-loaded fuel cell; however, achieving a complex pore structure in a simple manner presents a major challenge. In this work, by using the emulsion template method, a multiscale porous catalyst layer with macro- and mesopores was fabricated in a single step. A stable high internal phase emulsion is achieved with catalyst layer components by exploiting a Nafion ionomer as a surfactant. The oil phase of the emulsion catalyst slurry induces the macropores, and the Pt/C and ionomer mixture in the hydrophilic solvent forms a mesoporous framework in the catalyst layer. Scanning electron microscopy and micro X-ray computed tomography confirmed the formation of uniform and well-interconnected macropores. The performance of the low Pt-loaded catalyst layer derived from the emulsion template method considerably improved the mass transport property due to the mitigation of water flooding. The fabrication of an emulsion-based catalyst layer provides an efficient platform to design high-performance low Pt-loaded fuel cells.

Glutathione (GSH) is an anti-inflammatory and antioxidant biomolecule. Polycaprolactone (PCL) nanofiber mesh (NFM) is capable of the attachment and release of biomolecules for prolonged periods and has the potential as a transdermal drug delivery system during wound healing for a diabetic patient. Our earlier study found that high levels of sugar in diabetic male mice were significantly decreased by daily doses of glutathione administered on the mice. Furthermore, oxidative stress found in diabetic male mice led to the total depletion of glutathione levels in the body’s organs (pancreas, spleen, epididymis, and testis). The objective of this study was to attach GSH with PCL NFM for the controlled release of GSH biomolecules for long periods of time from the fiber mesh into a diabetic body. This study produced PCL NFM using an electrospun technique and tested it on mice to evaluate its efficiency as a dermal drug delivery mechanism. This study dissolved GSH (2.5 mg/mL) with phosphate-buffered saline (PBS) and glutaraldehyde (GLU) solution to create GSH-PBS and GSH-GLU complexes. Each complex was used to soak PCL NFM for 24 h and dried to create PCL-GSH-PBS and PCL-GSH-GLU meshes. Fiber morphology, degradation, fibroblast cell proliferation, cytotoxicity, and GSH release activities from each mesh were compared. Fibroblast cell adhesion and cytotoxicity tests found excellent biocompatibility of both GSH-immobilized PCL meshes and no degradation until 20 days of the study period. The disk diffusion method was conducted to test the antibacterial properties of the sample groups. Release tests confirmed that the attachment of GSH with PCL by GSH-GLU complex resulted in a steady release of GSH compared to the fast release of GSH from PCL-GSH-PBS mesh. The disk diffusion test confirmed that PCL-GSH-GLU has antibacterial properties. The above results conclude that GSH-GLU immobilized PCL NFM can be a suitable candidate for a transdermal anti-oxidative and anti-bacterial drug delivery system such as bandage, skin graft for wound healing application in a diabetic patient.

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Color stability of pulp-capping material is considered vital to the final aesthetic result since the material is placed in the coronal area. The purpose of this study was to compare the color stability of various pulp-capping materials by analyzing color change of tooth over time. A cavity was formed in the crown of the extracted premolar, and 4 types of pulp-capping materials were filled. Color assessment was performed with a spectrophotometer at different intervals: before placement; immediately after material placement; 1 day, 1 week, 2 weeks, 4 weeks, 8 weeks, 12 weeks, and 16 weeks after placement. Proroot white MTA® and TheraCal LC® showed a significant decrease in the L* value and an increase in the ΔE* value over time. In contrast, Biodentine® and Well-Root™ PT showed no significant change in the L* value and maintained a steady ΔE* value. The application of pulp-capping materials containing bismuth oxide as a radiopacifier may result in a color change of teeth. Long-term color stability of pulp-capping materials should be considered when treating teeth with thin enamel thickness or in aesthetically important area.