New Strategies in the Development of Antimicrobial Coatings: The Example of Increasing Usage of Silver and Silver Nanoparticles

Abstract

Bacterial infection from medical devices is a major problem and accounts for an increasing number of deaths as well as high medical costs. Many different strategies have been developed to decrease the incidence of medical device related infection. One way to prevent infection is by modifying the surface of the devices in such a way that no bacterial adhesion can occur. This requires modification of the complete surface with, mostly, hydrophilic polymeric surface coatings. These materials are designed to be non-fouling, meaning that protein adsorption and subsequent microbial adhesion are minimized. Incorporation of antimicrobial agents in the bulk material or as a surface coating has been considered a viable alternative for systemic application of antibiotics. However, the manifestation of more and more multi-drug resistant bacterial strains restrains the use of antibiotics in a preventive strategy. The application of silver nanoparticles on the surface of medical devices has been used to prevent bacterial adhesion and subsequent biofilm formation. The nanoparticles are either deposited directly on the device surface, or applied in a polymeric surface coating. The silver is slowly released from the surface, thereby killing the bacteria present near the surface. In the last decade there has been a surplus of studies applying the concept of silver nanoparticles as an antimicrobial agent on a range of different medical devices. The main problem however is that the exact antimicrobial mechanism of silver remains unclear. Additionally, the antimicrobial efficacy of silver on OPEN ACCESSPolymers 2011, 3 341 medical devices varies to a great extent. Here we will review existing antimicrobial coating strategies and discuss the use of silver or silver nanoparticles on surfaces that are designed to prevent medical device related infections.

Antimicrobial technology in orthopedic and spinal implants

“…Silver particles have several known mechanisms of action including binding to thiol groups of enzymes, cell membranes, and nucleic acids, resulting in structural abnormalities, a damaged cell envelope, and inhibition of cell division [39][40][41] . Silver nanoparticles (Figure 3) [42] are typically incorporated into titanium surfaces or polymeric coating to control the release rate and duration of the bioactive silver [11,[43][44][45] . Electrical currents are established when silver nanoparticles (cathode) embedded in a titanium matrix (anode) are exposed to electrolytes [45] -this galvanic coupling can cause changes in bacterial membrane morphology and DNA, leading to cell death [37] .…”

Designing an antibacterial acrylic resin using the cosolvent method —Effect of ethanol on the optical and mechanical properties of a cold-cure acrylic resin

“…The first is to alter the surface by coating it with appropriate agents or through chemical modification of the nearsurface layer 3) . The advantage of this approach is that the alteration is limited to the thin surface region; therefore, it does not affect any bulk material properties.…”

Antibacterial and antibiofilm activity of Ammi majus seed against Gram-positive bacteria

“…As a result, lead to increased interest in the search to identify the alternatives therapy for microbial control 7 and almost exclusively focused on the effects of these against planktonic biofilm forms that are more resistant to antimicrobial agents and therefore more difficult to control. 8 Some plants have been reported to be able to prevent the formation of biofilm in some bacteria such as Staphylococcus epidermidis, Staphylococcus aureus, Staphylococcus auricularis, Streptococcus mitis, Streptococcus salivarius, Streptococcus pneumoniae. [9][10][11] Among plants of the Apiaceae, family Ammi majus native to northern Africa, southern Europe, western Asia and India.…”