Galvanic zinc–copper microparticles inhibit melanogenesis via multiple pigmentary pathways

Electroactive nanofibrous membrane with temperature monitoring for wound healing

Developing functional dressings for promoting cellular activities and monitoring the healing progress is receiving increasingly widespread attention. In this study, Ag/Zn electrodes were deposited on the surface of a polylactic acid (PLA) nanofibrous membrane which can mimic the extracellular matrix. When wetted by wound exudate, the Ag/Zn electrodes could generate an electric stimulation (ES), promoting the migration of fibroblasts that heal wounds. Moreover, the Ag/Zn@PLA dressing showed excellent antibacterial activity against E. coli (95%) and S. aureus (97%). The study found that the electrostatic (ES) effect and the release of metal ions mainly contribute to the wound healing properties of Ag/Zn@PLA. In vivo mouse models demonstrated that Ag/Zn@PLA could promote wound healing by improving re-epithelialization, collagen deposition, and neovascularization. Additionally, the integrated sensor within the Ag/Zn@PLA dressing can monitor the wound site's temperature in real-time, providing timely information on wound inflammatory reactions. Overall, this work suggests that combining electroactive therapy and wound temperature monitoring may provide a new strategy for designing functional wound dressings.

Hydro electroactive Cu/Zn coated cotton fiber nonwovens for antibacterial and antiviral applications

In this study, Cu/Zn galvanic electrodes were sputtered on the two surfaces of hydrophilic cotton fiber nonwovens (Cotton) to prepare hydro electroactive Cu/Cotton/Zn composites. When the Cu/Cotton/Zn was used as a functional layer in the face mask, the Cu/Zn galvanic electrodes can be spontaneously activated by water vapor molecules exhaled by the human body and generate galvanic current. Based on this, the hydro electroactive Cu/Cotton/Zn demonstrated excellent antibacterial activity against Escherichia coli and Staphylococcus aureus and could deactivate Enterovirus 71 (EV71) virions transmitted through the respiratory tract by 97.72% after 15 min of contact. Moreover, the Cu/Cotton/Zn did not affect the particle filtration efficiency and breathability of the face mask's polypropylene (PP) melt-blown layer. Furthermore, the cytotoxicity assessment of Cu/Cotton/Zn showed no cytotoxicity, indicating good biological security. Overall, the Cu/Cotton/Zn may provide a new approach to increase the antibacterial and antiviral performance of current personnel protective equipment on the market.

Ag/Zn Galvanic Couple Cotton Nonwovens with Breath-Activated Electroactivity: A Possible Antibacterial Layer for Personal Protective Face Masks

The water vapor exhaled by the human body can severely accelerate the charge dissipation of commercial face masks, thereby reducing the electrostatic adsorption efficiency and increasing the bacterial invasion risk. This study developed an electroactive antibacterial cotton nonwoven (Ag/cotton/Zn) using eco-friendly magnetron sputtering technology. The Ag/Zn electrode constructed on the surface of cotton nonwovens could produce a microelectric field in the moist environment of human respiration, which endowed Ag/cotton/Zn with excellent electroactivity. When Ag/cotton/Zn was used as an additional layer of polypropylene melt-blown nonwovens or polylactic acid nanofibers, the prepared personal protective air filter had a filtration efficiency of up to 96.8% and an appropriate pressure drop and air permeability. The antibacterial results based on bacterial aerosols showed that the antibacterial efficiency against Escherichia coli and Staphylococcus aureus in 20 min was 99.74 and 99.79%, respectively, indicating an excellent electroactive killing efficiency against airborne bacteria. In addition, Ag/cotton/Zn showed excellent biological security. These results shed some light on the design and fabrication of next generation of personal protective air filter materials driven by human breathing.

Organogold drug Auranofin exhibits anti-melanogenic activity in B16F10 and MNT-1 melanoma cells

Auranofin (AF) is an organogold FDA-approved drug for treating rheumatism and has been repurposed for several pharmacological applications based on its anti-bacterial, anti-fungal and anti-inflammatory activities. To the best of our knowledge, there has been no study on effects of AF on melanogenesis yet. Hence, in this work, we studied the effect of AF on melanogenesis using B16F10 mouse melanoma cells and validated results in MNT-1 human melanoma cells. Melanogenesis assay was conducted with concentrations of AF determined to be nontoxic in B16F10 cells as well as HaCaT human epidermal cell line for a duration of 48 h, followed by various assays to delineate mechanisms of melanogenesis inhibition. Ultrastructural analysis was conducted to study further if AF affected melanosome maturation and protein levels of a key melanogenic protein, tyrosinase, and the maturation signaling molecule, cyclic adenosine monophosphate (cAMP), was estimated. Our results demonstrate that AF at nontoxic concentrations of 0.25-1 µM significantly inhibited melanin synthesis in a dose-dependent manner with significant inhibition of 32.85% at 1 µM. The study of mechanisms of melanogenesis inhibition revealed that AF inhibited tyrosinase activity in lysates of B16F10 cells but did not show a direct effect on purified mushroom tyrosinase activity or on copper chelation in a cell-free system, nor did it affect levels of B16F10 tyrosinase protein levels. However, AF significantly down-regulated cAMP levels, inhibited cellular ROS and increased number of melanosomes in immature stages, and also exhibited anti-melanogenic activity in B16F10-HaCaT cocultures. Furthermore, AF showed anti-melanogenic efficacy in MNT-1 cell monocultures and cocultures with an inhibition of intracellular tyrosinase activity. In summary, our results demonstrate a proof-of-principle for AF as a depigmenting agent for hyperpigmentation disorders and adjuvant for melanoma therapeutics.

Photoaging protective effects of BIOGF1K, a compound-K-rich fraction prepared from Panax ginseng

BACKGROUND

BIOGF1K, a compound-K-rich fraction, has been shown to display anti-inflammatory activity. Although Panax ginseng is widely used for the prevention of photoaging events induced by UVB irradiation, the effect of BIOGF1K on photoaging has not yet been examined. In this study, we investigated the effects of BIOGF1K on UVB-induced photoaging events.

METHODS

We analyzed the ability of BIOGF1K to prevent UVB-induced apoptosis, enhance matrix metalloproteinase (MMP) expression, upregulate anti-inflammatory activity, reduce sirtuin 1 expression, and melanin production using reverse transcription-polymerase chain reaction, melanin content assay, tyrosinase assay, and flow cytometry. We also evaluated the effects of BIOGF1K on the activator protein-1 signaling pathway, which plays an important role in photoaging, by immunoblot analysis and luciferase reporter gene assays.

RESULTS

Treatment of UVB-irradiated NIH3T3 fibroblasts with BIOGF1K prevented UVB-induced cell death, inhibited apoptosis, suppressed morphological changes, reduced melanin secretion, restored the levels of type I procollagen and sirtuin 1, and prevented mRNA upregulation of MMP-1, MMP-2, and cyclo-oxygenase-2; these effects all occurred in a dose-dependent manner. In addition, BIOGF1K markedly reduced activator-protein-1-mediated luciferase activity and decreased the activity of mitogen-activated protein kinases (extracellular response kinase, p38, and C-Jun N-terminal kinase).

CONCLUSION

Our results strongly suggest that BIOGF1K has anti-photoaging activity and that BIOGF1K could be used in anti-aging cosmeceutical preparations.