Young Ho Seo

Atopic dermatitis (AD) is a chronic inflammatory skin condition characterized by impaired barrier function and persistent inflammation, necessitating advanced therapeutic solutions. This study presents the development of a novel composite hydrogel scaffold composed of polyvinyl alcohol (PVA), gelatin, and Cnidium monnieri (CM) extract, designed to address the dual challenges of tissue regeneration and inflammation suppression. Fabricated via optimized freeze–thaw crosslinking and lyophilization, the scaffold exhibited a highly porous structure conducive to enhanced cell proliferation and controlled bioactive release. FT-IR analysis confirmed robust intermolecular interactions among PVA, gelatin, and CM bioactives, while SEM imaging revealed a well-developed porous network. The UPLC analysis demonstrated the sustained release of key CM compounds, such as osthole and imperatorin, which contributed to the scaffold’s anti-inflammatory properties. Biological assessments using HaCaT keratinocytes under inflammatory conditions induced by TNF-α and IFN-γ revealed improved cell viability and significant suppression of IL-8 expression, a critical marker in AD-related inflammation. These findings underscore the potential of the PVA/Gel/CM composite hydrogel as an advanced therapeutic platform for inflammatory skin disorders.

Flavonoids, present in plants as enriched secondary metabolites, prevent various stresses such as temperature fluctuations, acidity, and insect predation, are commonly found in leaves, stems, and flowers, and serve as important bioactive components. In this study, a total of eighteen different flavonoids, including one newly identified flavonoid glycoside, were successfully isolated from the pollen of Quercus mongolica. The structure of the novel compound was determined using nuclear magnetic resonance, mass spectrometry, and infrared spectroscopy. Additionally, GC analysis was conducted to determine the sugar moiety in the new compound, confirming the specific type of disaccharide present. The 18 compounds were classified as flavonoid glycosides (1–10), flavonoids (11–17), and isoflavone (18). All the isolated compounds were evaluated for their tyrosinase inhibitory and antioxidant activities, and their structure–activity relationships (SARs) were also evaluated. Compounds 12 and 16 showed higher tyrosinase inhibitory activities compared to kojic acid as positive control. Compounds 2, 5, 8, 12, 13, 14, and 16 demonstrated potent antioxidant activities. Among these compounds, 5 and 16 showed even higher antioxidant activity than the ascorbic acid. Structure–activity relationship analysis revealed that tyrosinase-inhibitory and antioxidant activities were enhanced in compounds with a hydroxy group of C-3 or C-3′t in flavonoid aglycones compared to their glycosides. These findings indicate that flavonoids and/or extracts from the pollen of Q. mongolica are valuable natural resources with applications in the pharmaceutical and cosmetic industries.

This study examined the tensile strength and biocompatibility properties of polyvinyl alcohol (PVA) hydrogel tissue regeneration scaffolds with polylactic acid (PLA) mesh fabric added as reinforcement, with a focus on the impact of heat treatment temperature and the number of layers of the PLA mesh fabric. The hydrogel scaffolds were prepared using a freeze–thaw method to create PVA hydrogel, with the PLA mesh fabric placed inside the hydrogel. The swelling ratio of the PVA/PLA hydrogel scaffolds decreased with increasing layer number and heat treatment temperature of the PLA mesh. The gel strength was highest when five layers of PLA mesh fabric were added, heat-treated at 120 °C, and confirmed to be properly placed inside the hydrogel by SEM images. The MTT assay and DAPI staining using HaCaT cells demonstrated that the cell proliferation was uninterrupted throughout the experimental period, confirming the biocompatibility of the scaffold. Therefore, we confirmed the possibility of using PLA mesh fabric as a reinforcement for PVA hydrogel to improve the strength of scaffolds for tissue regeneration, and we confirmed the potential of PLA mesh fabric as a reinforcement for various biomaterials.