Bactericidal effect of silver-reinforced carbon nanotube and hydroxyapatite composites

Abstract

Bacterial infection remains an important risk factor after orthopedic surgery. The present paper reports the synthesis of hydroxyapatite-silver (HA-Ag) and carbon nanotube-silver (CNT-Ag) composites via spark plasma sintering (SPS) route. The retention of the initial phases after SPS was confirmed by phase analysis using X-ray diffraction and Raman spectroscopy. Energy dispersive spectrum analysis showed that Ag was distributed uniformly in the CNT/HA matrix. The breakage of CNTs into spheroid particles at higher temperatures (1700) is attributed to the Rayleigh instability criterion. Mechanical properties (hardness and elastic modulus) of the samples were evaluated using nanoindentation testing. Ag reinforcement resulted in the enhancement of hardness (by ~15%) and elastic modulus (~5%) of HA samples, whereas Ag reinforcement in CNT, Ag addition does not have much effect on hardness (0.3 GPa) and elastic modulus (5 GPa). The antibacterial tests performed using Escherichia coli and Staphylococcus epidermidis showed significant decrease (by ~65-86%) in the number of adhered bacteria in HA/CNT composites reinforced with 5% Ag nanoparticles. Thus, Ag-reinforced HA/CNT can serve as potential antibacterial biocomposites.

Graphene-based antibacterial composite coatings electrodeposited on titanium for biomedical applications

“…An evaluation of E/H value is a prerequisite for the evaluation of fracture toughness [45,46]. In the case of pure HAP and Ag/HAP coatings, E r /H ratios were 17.86 and 11.87, respectively, while in the case of HAP/Gr and Ag/HAP/Gr coatings E r /H ratios were 12.90 and 11.81, respectively, indicating that Ag reinforcement caused decrements in the value of E r /H, implying that toughness increases with Ag addition [46].…”

Restriction of Phase Transformation in Carbon Nanotube-Reinforced Yttria-Stabilized Zirconia

“…[47] Moreover, lower hardness of the MWNT nanocomposites has also been reported for hydroxyapatite ceramics. [48] The decrease in hardness is attributed to increase in porosity upon MWNT addition. The elastic modulus was determined by the rule of mixtures using the volume percentage of the pure components, suitably incorporating the effect of porosity in the samples.…”

The use of nanomaterials to treat bone infections

“…A more recent study completed by Afzal et al 75 has been able to improve the distribution problem of silver nanoparticles as well by applying them to the surface of biocompatible carbon nanotubes (CNT), which have a more lattice structure for the nanoparticles to attach. Consequently, this was able to improve the antibacterial properties (Fig.…”