Curcumin-stabilized silver nanoparticles encapsulated in biocompatible electrospun nanofibrous scaffold for sustained eradication of drug-resistant bacteria

Due to the misuse of antibiotics, the emerging drug-resistance of pathogenic microbes has aroused considerable concerns for the public health, which demands the continuous search for safe and efficient antimicrobial treatment. In this study, curcumin reduced and stabilized silver nanoparticles (C-Ag NPs) were successfully encapsulated into electrospun nanofiber membranes consisted of polyvinyl alcohol (PVA) cross-linked by citric acids (CA), which exhibited desirable biocompatibility and broad-spectrum antimicrobial activities. The homogeneously distributed and sustained release of C-Ag NPs in the constructed nanofibrous scaffolds yield prominent killing effect against Escherichia coli, Staphylococcus aureus and Methicillin-resistant Staphylococcus aureus (MRSA), which involved the reactive oxygen species (ROS) generation. Outstanding elimination of bac-terial biofilms and excellent antifungal activity against Candida albicans was also identified after treated with PVA/CA/C-Ag. Transcriptomic analysis on MRSA treated by PVA/CA/C-Ag revealed the antibacterial process is related to disrupting carbohydrate and energy metabolism, as well as destroying bacterial membranes. Signifi-cant down-regulation of the expression of multidrug-resistant efflux pump gene sdrM was observed pointing to the role of PVA/CA/C-Ag to overcome the bacterial resistance. Therefore, the constructed ecofriendly and biocompatible nanofibrous scaffolds provide a robust and versatile nanoplatform of reversal potential to erad-icate drug-resistant pathogenic microbe in environmental as well as healthcare applications.

Automated summary

Due to antibiotic misuse, the emergence of drug-resistant pathogenic microbes has raised concern for public health. This study successfully encapsulated curcumin-reduced and stabilized silver nanoparticles (C-Ag NPs) into electrospun nanofiber membranes composed of polyvinyl alcohol (PVA) cross-linked with citric acid (CA), which demonstrated desirable biocompatibility and broad-spectrum antimicrobial activities. The constructed nanofibrous scaffolds exhibited a homogeneously distributed and sustained release of C-Ag NPs, resulting in a significant killing effect against Escherichia coli, Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus (MRSA), and Candida albicans, mediated by reactive oxygen species (ROS) generation. Transcriptomic analysis revealed that PVA/CA/C-Ag disrupted carbohydrate and energy metabolism and bacterial membranes, suggesting its potential in overcoming bacterial resistance and eradicating drug-resistant pathogenic microbes in various applications.