title: Antibacterial efficacy and cytotoxicity of low intensity direct current activated silver-titanium implant system prototype.
abstract: Silver-based devices activated by electric current are of interest in biomedicine because of their broad-spectrum antimicrobial activity. This study investigates the in vitro antibacterial efficacy and cytotoxicity of a low intensity direct current (LIDC)-activated silver-titanium implant system prototype designed for localized generation and delivery of silver ions at the implantation site. First, the antibacterial efficacy of the system was assessed against methicillin-resistant Staphylococcus aureus (MRSA) over 48 h at current levels of 3 and 6 µA in Mueller-Hinton broth. The cytotoxicity of the system was then evaluated over 48 h in two phases using an in vitro model with in which the activated electrodes were suspended in growth medium in a cell-seeded tissue culture plate. In phase-1, the system was tested on human osteosarcoma (MG-63) cell line and compared to titanium controls. In phase-2, the cytotoxicity characteristics were validated with normal human diploid osteoblast cells. The LIDC-activated system demonstrated high antimicrobial efficacy against MRSA, but was also toxic to human cells immediately surrounding the electrodes. The statistical analysis showed that the cytotoxicity was a result of the presence of silver, and the electric activation did not make it worse.
authors.affiliation: Edward P. Fitts Department of Industrial and Systems Engineering, North Carolina State University, Raleigh, NC, 27695, USA.|Department of Industrial, Manufacturing, and Systems Engineering, Texas Tech University, Lubbock, TX, 79409, USA.
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Tan
authors.affiliation: Department of Population Health and Pathobiology, North Carolina State University, Raleigh, NC, 27607, USA.
authors.forename: Edward A
authors.initials: EA
authors.lastname: Havell
authors.affiliation: Department of Population Health and Pathobiology, North Carolina State University, Raleigh, NC, 27607, USA.
authors.forename: Paul E
authors.initials: PE
authors.lastname: Orndorff
authors.affiliation: Edward P. Fitts Department of Industrial and Systems Engineering, North Carolina State University, Raleigh, NC, 27695, USA. rashirwaiker@ncsu.edu.|UNC-NCSU Joint Department of Biomedical Engineering, Raleigh, NC, 27695, USA. rashirwaiker@ncsu.edu.
authors.forename: Rohan A
authors.initials: RA
authors.lastname: Shirwaiker
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects; D007477:Ions / Q000737:chemistry; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects* / Q000472:pathogenicity; D012834:Silver / Q000737:chemistry / Q000494:pharmacology*; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000382:microbiology; D014025:Titanium / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000890:Anti-Infective Agents; D007477:Ions; D012834:Silver; D014025:Titanium
keywords: Antimicrobial efficacy; Cytotoxicity; Low intensity direct current; Orthopaedic application; Silver–titanium implant