Abstract
Total joint replacement (TJR), such as hip and knee replacement, is commonly used for the treatment of end stage arthritis. The use of Poly (methylmethacrylate) bone cement is a gold standard in such replacement, where it fixes the implant in place and transfer stresses between bone and implant, and frequently used for local delivery of drugs such as antibiotics. The use of antibiotic loaded bone cement is considered a well-established standard in the treatment and prophylaxis of Prosthetic joint infections (PJI). PJIs is a serious problem that decreases success rate of surgery and can be life threatening to patients, where the incidence can reach up 2% in total and hip replacements and up to 40% for revision surgery. Currently used antibiotic loaded bone cements have many limitations, including burst release of < 10% of antibiotic added. This burst release falls rapidly below inhibitory level within few days, which leads to selection of resistant antimicrobial strains and does not provide prophylaxis from early and delayed stage infection.
This study aims to provide a controlled release for gentamicin when loaded on Silica nanoparticles (NP) using layer-by-layer technique (LbL) to provide prophylaxis and treatment from postsurgical infections. The gentamicin loaded NPs were incorporated into PMMA bone cement and the new nanocomposite is characterized for gentamicin release, antimicrobial and mechanical properties.
Our results showed that the nanocomposite gentamicin release continued for 30 days at concentration 3 times higher than the commercial formulation containing the same amount of gentamicin, where burst release for few days were observed. Moreover, the nanocomposite showed superior antimicrobial inhibition for bacterial growth and good cytocompatibility without adversely affecting the cement compressive strength, bending and fracture toughness properties.
