To combat antimicrobial resistance, scientists search for novel treatments. Some of these therapies include nanoparticles, such as metal-based ones. In a bioprocess based on the fungus Fusarium oxysporum, Reyad M. El-Sharkawy, PhD, a microbiologist at Benha University in Egypt, and his colleagues made silver nanoparticles that can battle bacteria and even some cancer cells.
To do this, El-Sharkawy’s team cultured F. oxysporum, collected the root-like mycelium, and then added silver nitrate. It’s been known for some time that such a process can produce silver nanoparticles. El-Sharkawy and his colleagues wanted to produce small silver nanoparticles because the increase in surface area might improve therapeutic characteristics, such as adsorption and efficacy.
By optimizing the bioprocess, El-Sharkawy’s team produced silver nanoparticles with an average diameter of 5 nm. Plus, these scientists reported that these silver nanoparticles “exhibited significant antibacterial activity against multidrug-resistant bacterial pathogens in a concentration- and time-dependent manner.” For example, it took only about 0.08 µg/mL of these silver nanoparticles to inhibit Escherichia coli, which is one bacterium that is resistant to various conventional antibiotics, including ampicillin and tetracycline.
In addition to the antimicrobial features, these silver nanoparticles killed various cancer cells, including breast (MCF-7 cells), liver (HepG2 cells), and lung (A549). As El-Sharkawy and his colleagues noted: “The precise mechanism of cytotoxic activity of [silver nanoparticles] is not yet described.” Nonetheless, scientists know that silver nanoparticles can damage cell membranes, block the production of ATP, fragment DNA, and more—all of which could destroy cancer cells.
Although these silver nanoparticles might be developed for various biotherapeutic applications, El-Sharkawy’s team pointed out that scaling up the production to commercial levels faces some challenges. For example, these scientists noted that “further investigations are required to exactly identify and extract proteins responsible for [silver nanoparticle] biosynthesis.”
Turning silver nanoparticles into commercial products, though, could create a faster pathway to new antimicrobials and cancer treatments. For now, we think of fungus as a health problem, but it might one day turn into part of a healthcare solution as well.