Silk fibroin-based scaffolds for wound healing applications with metal oxide nanoparticles

In the last few years, wound healing and the development of "ideal" biomaterials that provide quick recovery and minimize scarring have represented one of the most important priorities of researchers. In this direction, silk fibroin (SF) scaffolds have gained substantial awareness, as a promising polymer owing to their increased biocompatibility, outstanding mechanical properties, and biodegradability, especially their tensile strength. Furthermore, SF is acknowledged to accelerate the wound healing process by encouraging cell growth and proliferation, and also the migration of different types of cells that are included in different stages of the healing process. Therefore, metal oxide nanoparticles (NPs), such as iron oxide (FeO), copper oxide (CuO), zinc oxide (ZnO), or magnesium oxide (MgO) NPs, have been extensively researched for their antimicrobial properties and ability to enhance tissue regeneration in addition to SF. When introduced within scaffolds, these NPs impart enhanced mechanical properties, including improved scaffold stability and durability. Moreover, the presence of the NPs could also increase the biocompatibility of scaffolds, facilitating cell proliferation, adhesion, and migration, ultimately promoting wound healing processes. The incorporation of metal oxide NPs and other natural polymers into SF scaffolds has thus emerged as a favorable method to enhance the properties and therapeutic potential of the developed biomaterial. This review aims to provide an overview of the advancements in SF scaffolds containing metal oxide NPs for wound healing applications.