A multi-material coating containing chemically-modified apatites for combined enhanced bioactivity and reduced infection via a drop-on-demand micro-dispensing technique
- 240 Downloads
Prevention of infection and enhanced osseointegration are closely related, and required for a successful orthopaedic implant, which necessitate implant designs to consider both criteria in tandem. A multi-material coating containing 1:1 ratio of silicon-substituted hydroxyapatite and silver-substituted hydroxyapatite as the top functional layer, and hydroxyapatite as the base layer, was produced via the drop-on-demand micro-dispensing technique, as a strategic approach in the fight against infection along with the promotion of bone tissue regeneration. The homogeneous distribution of silicon-substituted hydroxyapatite and silver-substituted hydroxyapatite micro-droplets at alternate position in silicon-substituted hydroxyapatite-silver-substituted hydroxyapatite/hydroxyapatite coating delayed the exponential growth of Staphylococcus aureus for up to 24 h, and gave rise to up-regulated expression of alkaline phosphatase activity, type I collagen and osteocalcin as compared to hydroxyapatite and silver-substituted hydroxyapatite coatings. Despite containing reduced amounts of silicon-substituted hydroxyapatite and silver-substituted hydroxyapatite micro-droplets over the coated area than silicon-substituted hydroxyapatite and silver-substituted hydroxyapatite coatings, silicon-substituted hydroxyapatite-silver-substituted hydroxyapatite/hydroxyapatite coating exhibited effective antibacterial property with enhanced bioactivity. By exhibiting good controllability of distributing silicon-substituted hydroxyapatite, silver-substituted hydroxyapatite and hydroxyapatite micro-droplets, it was demonstrated that drop-on-demand micro-dispensing technique was capable in harnessing the advantages of silver-substituted hydroxyapatite, silicon-substituted hydroxyapatite and hydroxyapatite to produce a multi-material coating along with enhanced bioactivity and reduced infection.
KeywordsHydroxyapatite Osteocalcin Coated Sample Microbial Adhesion Vortexed Solution
This work was supported by the Ministry of Education Academic Research Fund (Singapore) Project number MOE2013-T2-1-074.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no competing interests.
- 13.Friederichs RJ, Chappell HF, Shepherd DV, Best SM. Synthesis, characterization and modelling of zinc and silicate co-substituted hydroxyapatite. J R Soc Interface. 2015;12.Google Scholar
- 26.Hayek E, Newesely H, Rumpel ML, Pentacalcium Monohydroxyorthophosphate. In: Kleinberg J, editor. Inorganic Syntheses. John Wiley & Sons, Inc., Hoboken, NJ, USA. 2007. pp. 63–5.Google Scholar
- 28.My Assay. Online Data Analysis. 2013: http://www.myassays.com/four-parameter-logistic-curve.assay.
- 30.Schwarz K. Proceedings: recent dietary trace element research, exemplified by tin, fluorone, and silicon. Fed Proc. 1974;33:1748–57.Google Scholar
- 32.Birchall JDEA. Biological implications of the interaction (via silanol groups) of silicon with metal ions. Ciba Found Symp. 1986;121:140–59.Google Scholar