An innovative, easily fabricated, silver nanoparticle-based titanium implant coating: development and analytical characterization

Abstract

Microbial colonization and biofilm formation on implanted devices represent an important complication in orthopaedic and dental surgery and may result in implant failure. Controlled release of antibacterial agents directly at the implant site may represent an effective approach to treat these chronic complications. Resistance to conventional antibiotics by pathogenic bacteria has emerged in recent years as a major problem of public health. In order to overcome this problem, non-conventional antimicrobial agents have been under investigation. In this study, polyacrylate-based hydrogel thin coatings have been electrosynthesised on titanium substrates starting from poly(ethylene glycol diacrylate)-co-acrylic acid. Silver nanoparticles (AgNPs) with a narrow size distribution have been synthesized using a "green" procedure and immobilized on Ti implant surfaces exploiting hydrogel coatings' swelling capabilities. The coatings have been characterized by XPS and SEM/EDX, while their silver release performances have been monitored by ICP-MS. The antibacterial activity of these AgNP-modified hydrogel coatings was tested evaluating in vitro inhibition growth of Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli, among the most common pathogens in orthopaedic infections. Moreover, a preliminary investigation of the biocompatibility of silver-loaded coatings versus MG63 human osteoblast-like cells has been performed. An important point of strength of this paper, in fact, is the concern about the effect of silver species on the surrounding cell system in implanted medical devices. Silver ion release has been properly tuned in order to assure antibacterial activity while preserving osteoblasts' response at the implant interface.

Hierarchical micro/nanostructured titanium with balanced actions to bacterial and mammalian cells for dental implants

“…10,11 Ag NPs have promising antibacterial activity but the small size and high mobility raise safety concerns due to their potential cytotoxicity. 26 In this study, size tunable Ag NPs were fabricated and incorporated onto SLA surfaces by manipulating the ASH effect of Ag-PIII. It was found that immobilization of Ag NPs on SLA-treated titanium gave rise to both good antibacterial activity and excellent compatibility with mammalian cells (Figure 12).…”

“…25 For instance, Zhao et al 25 and De Giglio et al 26 have reported that coatings incorporating Ag NPs exhibit some cytotoxicity toward osteoblasts, which is probably due to the silver ions (Ag + ) released by Ag NPs. 27 Hence, restricting the mobility of Ag NPs by immobilization is crucial in reducing the toxic effect.…”

Efficacy of silver/hydrophilic poly(p-xylylene) on preventing bacterial growth and biofilm formation in urinary catheters

“…It must be considered that not only Ag þ ions but also silver nanoparticles migrate through the PPX cap layer. 31 Silver nanoparticles can interact with biological fluids as metallic particles (Ag 0 ) or can be oxidized to Ag þ . 20 However, ICP-OES cannot discriminate between these two species; therefore, release of both species by measuring the sample solutions by this method cannot be excluded.…”

Decreased bacterial growth on titanium nanoscale topographies created by ion beam assisted evaporation

“…13 While many treatments can create similar roughness measurements, such as adding coatings onto the surface via electrophoretic deposition, 2 electrochemical anodizing [14][15][16] and silver nanoparticle-embedded hydrogelbased coatings, 17 the morphology of the resulting surfaces can vary drastically. Lorenzetti et al 11 used hydrothermal treatments to generate nanorough surfaces on titanium and found that macro-and microscale grooves (results of the initial material machining process) provided niches for bacteria to adhere and proliferate on, despite high roughness values.…”

“…Lorenzetti et al 11 used hydrothermal treatments to generate nanorough surfaces on titanium and found that macro-and microscale grooves (results of the initial material machining process) provided niches for bacteria to adhere and proliferate on, despite high roughness values. Silver is one of the most prominent non-small-molecule drugs used for antibacterial applications, 3,[17][18][19] but can be expensive and mildly toxic to surrounding mammalian cells. 20,21 Additionally, adding different materials to the surface may lead to imperfectly fused layers that may eventually wear or delaminate from the bulk implant.…”