The effect of Co-encapsulated GNPs-CNTs nanofillers on mechanical properties, degradation and antibacterial behavior of Mg-based composite

J Mech Behav Biomed Mater. 2023 Feb:138:105601. doi: 10.1016/j.jmbbm.2022.105601. Epub 2022 Nov 30.

Abstract

Magnesium (Mg)-based composites, as one group of the biodegradable materials, enjoy high biodegradability, biocompatibility, and non-toxicity making them a great option for implant applications. In this paper, by the semi powder metallurgy (SPM) technique, the graphene nano-platelets (GNPs) and carbon nanotubes (CNTs) nanosystems, as reinforcements, are dispersed homogenously in the Mg-Zn (MZ) alloy matrix. Subsequently, the composite is successfully produced employing the spark plasma sintering (SPS) process. Compared to the unreinforced MZ sample, GNPs + CNTs mixture reinforced composite exhibits higher compressive strength (∼75%). Notably, adding only 1 wt % of GNPs + CNTs to the MZ matrix reduces the rate of the degradation in the Mg-based composite by almost 2- fold. Examining the antibacterial activity demonstrate that the incorporation of GNPs + CNTs into the Mg-based matrix is likely to prevent the infiltration and development of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) significantly. While the MTT with 0.5 and 1 wt % GNPs + CNTs does not demonstrate cytotoxicity to the MG63 cells, the excessive GNPs + CNTs results in a certain degree of poisonousness. In general, the findings of the present research attest to the viable application of MZ/GNPs + CNTs composites for implants as well as bone infection treatment.

Keywords: Antibacterial activity; Biocompatibility; Carbon nanotubes; Graphene nano-platelets; Mechanical properties; Mg-based composite.

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Escherichia coli
  • Graphite*
  • Magnesium / pharmacology
  • Nanotubes, Carbon*
  • Staphylococcus aureus

Substances

  • Nanotubes, Carbon
  • Magnesium
  • Graphite
  • Anti-Bacterial Agents