Antibacterial Longevity of a Novel Gallium Liquid Metal/Hydroxyapatite Composite Coating Fabricated by Plasma Spray

Duy Quang Pham, Sheeana Gangadoo, Christopher C. Berndt, James Chapman, Jiali Zhai, Krasimir Vasilev, Vi Khanh Truong, Andrew S.M. Ang

Research output: Contribution to journalArticlepeer-review

10 Citations (Scopus)


Hydroxyapatite (HAp)-coated metallic implants are known for their excellent bioactivity and osteoconductivity. However, infections associated with the microstructure of the HAp coatings may lead to implant failures as well as increased morbidity and mortality. This work addresses the concerns about infections by developing novel composite coatings of HAp and gallium liquid metal (GaLM) using atmospheric plasma spray (APS) as the coating technique. Five weight percent Ga was mixed into a commercially supplied HAp powder using an orbital shaker; then, the HAp-Ga particle feedstock was coated onto Ti6Al4V substrates using the APS technique. The X-ray diffraction results indicated that Ga did not form any Ga-related phases in either the HAp-Ga powder or the respective coating. The GaLM filled the pores of the HAp coating presented both on the top surface and within the coating, especially at voids and cracks, to prevent failures of the coating at these locations. The wettability of the surface was changed from hydrophobic for the HAp coating to hydrophilic for the HAp-Ga composite coating. Finally, the HAp-Ga coating presented excellent antibacterial efficacies against both initial attachments and established biofilms generated from methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa after 18 h and 7 days of incubation in comparison to the control HAp coating. This study shows that GaLM improves the antibacterial properties of HAp-based coatings without sacrificing the beneficial properties of conventional HAp coatings. Thus, the HAp-Ga APS coating is a viable candidate for antibacterial coatings.

Original languageEnglish
Pages (from-to)18974-18988
Number of pages15
JournalACS Applied Materials and Interfaces
Issue number16
Publication statusPublished - 27 Apr 2022


  • antibacterial
  • gallium
  • hydroxyapatite
  • liquid metal
  • mechanical properties
  • MRSA
  • nanoindentations
  • plasma-sprayed coatings
  • Pseudomonas aeruginosa


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