Synergistic Wound Healing by Novel Ag@ZIF-8 Nanostructures

Abstract

In this paper, novel zeolitic imidazolate framework-8 (ZIF-8) functionalized with Ag (Ag@ZIF-8) nanoparticles were synthesized through a green, facile and environmental-friendly process for wound dressing applications. X-ray diffraction revealed that the ZIF-8 and Ag@ZIF-8 were successfully synthesized by green solvents at ambient temperature. Field-emission scanning electron microscopy indicated a homogeneous porous blend of ∼30 nm chitosan/bacterial cellulose (CS/BC) nanofibers embedded with ∼80-110 nm nanoparticles of the ZIF-8 and Ag@ZIF-8. Transmission electron microscopy revealed the Ag@ZIF-8 nanostructures consist of ZIF-8 cores that are covered by 5-20 nm Ag nanoparticles. MTT assay indicated excellent cell viability values of ∼115 and 109% for the CS/BC nanocomposites reinforced by ZIF-8 and Ag@ZIF-8 nanoparticles, respectively. The Ag-containing wound dressings showed 52-300% of effective antibacterial activities. Animal studies demonstrated excellent healing for the wound treated by CS/BC-25%Ag@ZIF-8 nanocomposite with ∼91% of wound closure after 14 days of treatment. Hematoxylin and eosin (H&E) staining revealed successful healing and tissue regeneration for the wounds treated using the CS/BC-Ag@ZIF-8 nanocomposites. This kind of nanocomposites with synergistic antimicrobial and bioactivity properties can be a promising candidate for regenerative medicine.

Keywords: Bacterial Cellulose; Chitosan; Silver; Wound Dressing; ZIF-8.