Examining the wound healing potential of curcumin-infused electrospun nanofibers from polyglutamic acid and gum arabic.

Advancements in medicine have led to continuous enhancements and innovations in wound dressing materials, making them pivotal in medical care. We used natural biological macromolecules, γ-polyglutamic acid and gum arabic as primary raw materials to create nanofibers laden with curcumin by blending electrostatic spinning technology in the current investigation. These nanofibers were meticulously characterized using fluorescence microscopy, scanning electron microscopy, Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), and X-ray diffraction (XRD). Our comprehensive analyses confirmed the successful encapsulation of curcumin within the nanofiber carrier and it has uniform diameter, good water absorption and mechanical properties. Subsequently, we evaluated the antimicrobial effects of these curcumin-loaded nanofibers against Staphylococcus aureus through an oscillating flask method. We created a mouse model with acute full-thickness skin defects to further investigate the wound healing potential. We conducted various biochemical assays to elucidate the mechanism of action. The results revealed that curcumin nanofibers profoundly impacted wound healing. They bolstered the expression of TGF-ß1 and VEGF and reduced the expression of inflammatory factors, leading to an accelerated re-epithelialization process, enhanced wound contraction, and increased regeneration of new blood vessels and hair follicles. Furthermore, these nanofibers positively influenced the proportion of three different collagen types. This comprehensive study underscores the remarkable potential of curcumin-loaded nanofibers to facilitate wound healing and lays a robust experimental foundation for developing innovative, natural product-based wound dressings.

Recent intensified erosion and massive sediment deposition in Tibetan Plateau rivers.

Recent climate change has caused an increase in warming-driven erosion and sediment transport processes on the Tibetan Plateau (TP). Yet a lack of measurements hinders our understanding of basin-scale sediment dynamics and associated spatiotemporal changes. Here, using satellite-based estimates of suspended sediment, we reconstruct the quantitative history and patterns of erosion and sediment transport in major headwater basins from 1986 to 2021. Out of 13 warming-affected headwater regions, 63% of the rivers have experienced significant increases in sediment flux. Despite such intensified erosion, we find that 30% of the total suspended sediment flux has been temporarily deposited within rivers. Our findings reveal a pronounced spatiotemporal heterogeneity within and across basins. The recurrent fluctuations in erosion-deposition patterns within river channels not only result in the underestimation of erosion magnitude but also drive continuous transformations in valley morphology, thereby endangering local ecosystems, landscape stability, and infrastructure project safety.

l-Arginine induces antioxidant response to prevent oxidative stress via stimulation of glutathione synthesis and activation of Nrf2 pathway.

Arginine is a conditionally essential amino acid. To elucidate the influence of l-arginine on the activation of endogenous antioxidant defence, male Wistar rats were orally administered daily with l-arginine at different levels of 25, 50, 100 mg/100 g body weight. After 7 and 14 days feeding, the antioxidative capacities and glutathione (GSH) contents in the plasma and in the liver were uniformly enhanced with the increasing consumption of l-arginine, whereas the oxidative stress was effectively suppressed by l-arginine treatment. After 14 days feeding, the mRNA levels and protein expressions of Keap1 and Cul3 were gradually reduced by increasing l-arginine intake, resulting that the nuclear factor Nrf2 was activated. Upon activation of Nrf2, the expressions of antioxidant responsive element (ARE)-dependent genes and proteins (GCLC, GCLM, GS, GR, GST, GPx, CAT, SOD, NQO1, HO-1) were up-regulated by l-arginine feeding, indicating an upward trend in antioxidant capacity uniformly with the increasing consumption of l-arginine. The present study demonstrates that the supplementation of l-arginine stimulates GSH synthesis and activates Nrf2 pathway, leading to the up-regulation of ARE-driven antioxidant expressions via Nrf2-Keap1 pathway. Results suggest the availability of l-arginine is a critical factor to suppress oxidative stress and induce an endogenous antioxidant response.