Silver Ions Found Effective in Fighting Infections while Forming Bone

An international team of researchers have developed a silver ion-coated scaffold that kills methicillin-resistant Staphylococcus aureus (MRSA) while growing bone, findings that could potentially treat or prevent osteomyelitis in the future.

A team of international researchers created scaffolds from polylactic acid (PLA) polymer, an FDA-approved biodegradable material. They then applied a silver ion release coating to the scaffolds and seeded them fat-derived adult stem cells that could be triggered to create bone cells. Further, the researchers seeded scaffolds with MRSA to see if silver ions could fight and even kill the bacteria. The silver ion-releasing scaffolds inhibited MRSA and supported bone tissue formation.

“Silver is well known for its antimicrobial properties and is highly toxic to a wide range of microorganisms such as MRSA,” said Elizabeth Loboa, dean of the University of Missouri College of Engineering and the professor of bioengineering who led the research team. “Silver ions work mechanically—they actually disrupt the cellular machinery of MRSA. Our research now has shown that bone tissues still can be formed, even in the presence of MRSA. We’ve created the materials needed for bone tissue engineering that will allow patients to use their own fat cells to create patient-specific bone and surgically implant those cells and tissues while diminishing, or potentially eliminating, the risk of MRSA infection.”

Additional studies are underway and, if successful, the researchers plan to move to human studies. Loboa said one concern is the amount of silver ions used.

“It’s a fine line,” she said. “If you overuse too much of the silver, it’s bad for the mammalian cells. We want to make sure we don’t hurt our host cells, but kill the bacterial cells.”

A rise in MRSA and other strains of infection are creating challenges for surgeons, a topic covered in the August 2016 issue of BONEZONE. Orthopaedic companies large and small have infection prevention products in the pipeline to combat potential post-surgical infections.