A novel hydroxyapatite film coated with ionic silver via inositol hexaphosphate chelation prevents implant-associated infection

Abstract

Various silver-coated implants have been developed to prevent implant-associated infections, and have shown dramatic effects in vitro. However, the in vivo results have been inconsistent. Recent in vitro studies showed that silver exerts antibacterial activity by mediating the generation of reactive oxygen species in the presence of oxygen. To maintain its antibacterial activity in vivo, the silver should remain in an ionic state and be stably bound to the implant surface. Here, we developed a novel bacteria-resistant hydroxyapatite film in which ionic silver is immobilized via inositol hexaphosphate chelation using a low-heat immersion process. This bacteria-resistant coating demonstrated significant antibacterial activity both in vitro and in vivo. In a murine bioluminescent osteomyelitis model, no bacteria were detectable 21 days after inoculation with S. aureus and placement of this implant. Serum interleukin-6 was elevated in the acute phase in this model, but it was significantly lower in the ionic-silver group than the control group on day 2. Serum C-reactive protein remained significantly higher in the control group than the ionic-silver group on day 14. Because this coating is produced by a low-heat immersion process, it can be applied to complex structures of various materials, to provide significant protection against implant-associated infections.

Antimicrobial strategies for urinary catheters

“…To improve the antimicrobial efficacy, an increasing number of novel silver materials have been developed . Silver nanoparticles (Ag NPs) are one of the most attractive material for catheter coatings [Fig.…”

“…To improve the antimicrobial efficacy, an increasing number of novel silver materials have been developed. [38][39][40][41][42][43][44][45][46][47][48] Silver nanoparticles (Ag NPs) are one of the most attractive SCHEME 2. Mechanisms of bactericidal silver ion.…”

“…The Ag NPs are primarily composed of Ag 0 metal with a particle size of <100 nm and very large surfaceto-volume ratio. The microorganisms inhibition mechanism of Ag NPs is related to (1) the release of antibacterial Ag + ion from particle surface [38][39][40][41][42][43][44][45][46][47][48] ; (2) the incorporation of Ag NPs into the bacterial membrane, leading to structural damages and compromised membrane functions, including increase in permeability, disruption of regulated plasma membrane transport, and eventually, causing cell death. 49,50 In addition, silver can be combined with other active materials, showing improved antimicrobial efficacy, for instance, silver coating releasing hydroxyapatite materials, 53 52 The silver-impregnated catheters will continue to play an important role, owing to its broad-spectrum antimicrobial ability, simple preparation, and less side effects.…”

Biomimetics of Bone Implants: The Regenerative Road

“…8 Similarly, osteomyelitic bone is a major contraindication for implants, considering the likelihood of infectious staphylococci biofilm formation. 9,10 To ensure a fit of the implant in the host bone, under-reaming is often performed. This is a drilling process designed to facilitate the implant, which is sometimes known to fracture the host bone further.…”

Surface modification of valve metals using plasma electrolytic oxidation for antibacterial applications: A review

“…Biomaterials associated infection has become a significant problem with increasing number of biomedical implants particularly due to the ever‐increasing resistance of microbes against conventional antibiotic strategies . These infections may result serious complication in patients, including pain and increased risk of implant failure. Almost 1.5 to 7.2% postoperative problems in health care regime are caused due to medical devices .…”