Graphene oxide in zinc alginate films: Antibacterial activity, cytotoxicity, zinc release, water sorption/diffusion, wettability and opacity

PLoS One. 2019 Mar 7;14(3):e0212819. doi: 10.1371/journal.pone.0212819. eCollection 2019.

Abstract

Alginate is considered an exceptional biomaterial due to its hydrophilicity, biocompatibility, biodegradability, nontoxicity and low-cost in comparison with other biopolymers. We have recently demonstrated that the incorporation of 1% graphene oxide (GO) into alginate films crosslinked with Ca2+ cations provides antibacterial activity against Staphylococcus aureus and methicillin-resistant Staphylococcus epidermidis, and no cytotoxicity for human keratinocyte HaCaT cells. However, many other reports in literature have shown controversial results about the toxicity of GO demanding further investigation. Furthermore, the synergic effect of GO with other divalent cations with intrinsic antibacterial and cytotoxic activity such as Zn2+ has not been explored yet. Thus, here, two commercially available sodium alginates were characterised and utilized in the synthesis of zinc alginate films with GO following the same chemical route reported for the calcium alginate/GO composites. The results of this study showed that zinc release, water sorption/diffusion and wettability depended significantly on the type of alginate utilized. Furthermore, Zn2+ and GO produced alginate films with increased water diffusion, wettability and opacity. However, neither the combination of GO with Zn2+ nor the use of different types of sodium alginates modified the antibacterial activity and cytotoxicity of the zinc alginates against these Gram-positive pathogens and human cells respectively.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alginates / pharmacology*
  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacology*
  • Biocompatible Materials / chemistry
  • Biocompatible Materials / pharmacology*
  • Cell Line
  • Graphite / pharmacology*
  • Humans
  • Keratinocytes
  • Microbial Sensitivity Tests
  • Staphylococcus aureus / drug effects
  • Staphylococcus epidermidis / drug effects
  • Toxicity Tests
  • Wettability
  • Zinc / pharmacology*

Substances

  • Alginates
  • Anti-Bacterial Agents
  • Biocompatible Materials
  • graphene oxide
  • Graphite
  • Zinc

Grants and funding

The authors would like to acknowledge the Universidad Católica de Valencia San Vicente Mártir and the Ministry of Economy, Industry and Competitiveness for the financial support of this work through the 2018-231-001UCV and MAT2015-69315-C3-1-R grants respectively. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.