The release properties of silver ions from Ag-nHA/TiO ₂ /PA66 antimicrobial composite scaffolds

Abstract

Implant-associated bacterial infection can jeopardize the clinical success of implants and result in loss of supporting bone. The purpose of this study was to develop a novel porous scaffold with long-term antibacterial activity for bone repair or regeneration. Porous nano-hydroxyapatite/titania/polyamide66 scaffolds containing different amounts of silver ions (Ag-nHA/TiO(2)/PA66) were prepared by a phase inversion technique. The release of silver ions from the porous scaffolds in simulated body fluid (SBF) and in the F12 cell culture medium was evaluated via atomic absorption spectrometry. The results showed that the release of Ag(+) was time and concentration dependent, increasing with the immersion time and the silver content in the scaffolds. On the other hand, the release property of Ag(+) was also influenced by the immersion medium. The cumulative Ag(+) release in the F12 medium with time increase parabolically, different from the linear increase or the zero-order release kinetics in the SBF medium. Compared to the slight fluctuation of the Ag(+) release rate in SBF during the whole immersion period, the initial fast release rate and the later sustained release rate of Ag(+) in the F12 medium could be more helpful for preventing implant-associated infection. Since the Ag-nHA/TiO(2) particles were embedded in the PA66 matrix, the long-term-sustained release should be related both to the relaxation of PA macromolecular chains due to the penetration of water and to the slow release of the substituted Ag(+) ions in the HA lattice. The sustained Ag(+) release with time indicates that the composite scaffold is suitable for a long-term antimicrobial application during the scaffold-assisted bone repair or regeneration.

Physio-chemical and antibacterial characteristics of pressure spun nylon nanofibres embedded with functional silver nanoparticles

“…Although samples 9, 10 and 11 (which are for 4 wt.% Ag-loaded nylon nanofibres) show a reduction in Ag ion concentration, the rate of ion release for consecutive washing cycles does not show a significant variation. These results show a similar trend to the results obtained with Ag ion release from polyamide 66 composites where faster release is observed in the initial period and subsequently the release abruptly slows down [30]. It is also clearly seen that the Ag ion concentration in the solution is higher after each cycle of wash for 4 wt.% Ag-loaded samples compared to the others.…”

Synthesis of titanium oxide thin films containing antibacterial silver nanoparticles by a reactive magnetron co-sputtering system for application in biomedical implants

“…Overall, the minimum requirement for antibacterial efficacy (0.1 ppb) was exceeded [28] in both solutions at all conditions. As previously reported, the Ag ion release property was influenced by the immersion medium [29]. Small variations between the experimental groups were attributed to two factors.…”

Interfacial Engineering of Bimetallic Ag/Pt Nanoparticles on Reduced Graphene Oxide Matrix for Enhanced Antimicrobial Activity

“…Taken together, these results suggest the role of bimetallic components on the enhanced antimicrobial activity owing to the initial burst and the sustained release of silver ions. 54,55 To further investigate the viability of the bacteria incubated with different nanocomposites, we stained the bacteria using DAPI and CTC, respectively. DAPI with blue fluorescence can stain both live and dead cells, whereas CTC is used to label live cells by taking advantage of the intracellular red fluorescent precipitate resulting from the reduction of the CTC to CTCformazan through bacterial respiration.…”