Inhibition of Biofilm Formation on Orthopedic Implants Based on Spider Silk Coatings Increases Survival of Galleria mellonella

Abstract

The microbial repellence of some spider silk-based materials makes them interesting candidates for biomedical applications. This study investigates the microbial repellent properties of recombinant spider silk coatings on orthopedic metal implants, specifically targeting the prevention of biofilm-related implant infections caused by multidrug-resistant bacteria such as Staphylococcus aureus. Utilizing Galleria mellonella as an in vivo model, stainless steel and titanium implants coated with films made of three different recombinant spider silk proteins are analyzed concerning biofilm formation and its impact on animal survival. Amongst the tested spider silk variants, the polyanionic eADF4(C16) demonstrates superior bacterial-repellent properties and improved larval survivability. Scanning electron microscopy analysis reveals reduced bacterial presence on eADF4(C16)-coated wires compared to uncoated controls, correlating with survival data. Based on the results, the potential of recombinant spider silk coatings to enhance implant functionality and longevity is highlighted, presenting a novel solution to combat biofilm-related implant infections and address the growing threat of antimicrobial resistance. Furthermore, employing Galleria mellonella as an in vivo model underscores a commitment to ethical research practices in studying biofilm infections.