Phage-Loaded Biomimetic Apatite Powder With Antibiofilm Activity to Treat Bone-Associated Infections

For decades, calcium phosphate (CaP)-based ceramics have been used for coating of bone and joint substitutes after arthroplasty due to their biocompatible properties. Infections following orthopedic replacement occur in 1%–5% of cases, causing serious complications. Biofilm formation either on the biomaterial's surface or on patient's tissues greatly enhances the resistance against antibiotic treatments and can induce a chronic infection, emphasizing the need for novel antimicrobial delivery systems. In this study, we established a protocol enabling bacteriophage loading during the synthesis of a CaP-based powder. The resulting biomaterial proved to be noncytotoxic against human osteoblastic cells and able to significantly inhibit 24-h matured S. aureus biofilm cultures or even completely eradicate it after 5 days of contact. Additional S. aureus biofilm assays with a freeze-dried material using two different excipients showed that sucrose had a protective role against Remus bacteriophage treatment of S. aureus biofilms, whereas lactose-freeze-dried powder maintained the antibiofilm activity.