Historically, spider silk has been used to treat a variety of ailments, ranging from skin lesions to warts. There was even a time when doctors would cover open wounds with cobwebs, whilst patients were also advised to place cocoons on infected teeth.
However, in more recent times it has been debated whether spider’s silk actually has any antimicrobial properties.
Recently, in the journal iScience, researchers revisited these old experiments and debunked the myth of antibiotic spider silk.
Senior author Trine Bilde, a professor of biology at Aarhus University, expressed doubt concerning the validity of what they had read in the literature surrounding this topic. She said, “We were unable to detect antimicrobial activity of social spider silk, regardless of method or microbe, and this made us curious about why other studies were able to. We then started scrutinizing the papers reporting antimicrobial activity in fine detail and became aware of methodological shortcomings.”
These methodical shortcomings included a risk for bacteria contamination and inadequate control for the solvent used to extract the spider silk. This lead the team to conclude that the previous reports had likely measured the effect of the solvent used to extract spider silk - rather than the spider silk itself – as solvents like acetone or ethyl acetate can have strong antimicrobial effects on their own.
Trine’s team used an improved experimental method to examine silk from seven different species of spider and found no signs of antimicrobial activity.
This is great news for arachnophobes, as science would suggest there is no need to revisit spider silk treatments!