title: Can a novel silver nano coating reduce infections and maintain cell viability in vitro?
abstract: Herein we report a facile layer-by-layer method for creating an antimicrobial coating composed of silver nanoparticles on medical grade titanium test discs. Nanoscale silver nanoparticle layers are attached to the titanium orthopedic implant material via aminopropyltriethoxy silane crosslinker that reacts with neighboring silane moieties to create an interconnected network. A monolayer of silane, followed by a monolayer of silver nanoparticles would form one self-assembled layer and this process can be repeated serially, resulting in increased silver nanoparticles deposition. The release rate of silver ion increases predictably with increasing numbers of layers and at appropriate thicknesses these coatings demonstrate 3-4 log reduction of viable Escherichia coli and Staphylococcus aureus bacteria. Increasing the thickness of the coatings resulted in reduced bacterial colonization as determined by fluorescent staining and image analysis. Interestingly, the cytotoxicity of murine 3T3 cells as quantified by fluorescent staining and flow cytometry, was minimal and did not vary significantly with the coating thickness. Additionally, these coatings are mechanically stable and resist delamination by orthogonal stress test. This simple layer-by-layer coating technique may provide a cost-effective and biocompatible method for reducing microbial colonization of implantable orthopedic devices.
authors.affiliation: 1Department of Biological and Agricultural Engineering, Louisiana State University and Agricultural Center, Baton Rouge, USA.
authors.forename: Ammar T
authors.initials: AT
authors.lastname: Qureshi
authors.forename: Jace P
authors.initials: JP
authors.lastname: Landry
authors.forename: Vinod
authors.initials: V
authors.lastname: Dasa
authors.forename: Marlene
authors.initials: M
authors.lastname: Janes
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Hayes
mesh_terms: D016475:3T3 Cells; D000818:Animals; D001422:Bacterial Adhesion; D001424:Bacterial Infections / Q000382:microbiology / Q000517:prevention & control*; D002470:Cell Survival; D020099:Coated Materials, Biocompatible; D004926:Escherichia coli / Q000302:isolation & purification; D066298:In Vitro Techniques; D053768:Metal Nanoparticles / Q000737:chemistry*; D051379:Mice; D008826:Microbial Sensitivity Tests; D008855:Microscopy, Electron, Scanning; D012834:Silver / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013211:Staphylococcus aureus / Q000302:isolation & purification; D020349:Surface Plasmon Resonance; D013718:Tensile Strength
chemical_list: D020099:Coated Materials, Biocompatible; D012834:Silver
keywords: Orthopedic implants; non-cytotoxic; self-assembled monolayer; silane linker; silver nanoparticles (SNPs)