Gallium incorporation into phosphate based glasses: Bulk and thin film properties

Bryan W Stuart; Colin A Grant; George E Stan; Adrian C Popa; Jeremy J Titman; David M Grant

doi:10.1016/j.jmbbm.2018.03.041

Gallium incorporation into phosphate based glasses: Bulk and thin film properties

J Mech Behav Biomed Mater. 2018 Jun:82:371-382. doi: 10.1016/j.jmbbm.2018.03.041. Epub 2018 Mar 30.

Authors

Bryan W Stuart¹, Colin A Grant², George E Stan³, Adrian C Popa⁴, Jeremy J Titman⁵, David M Grant⁶

Affiliations

¹ Advanced Materials Research Group, Faculty of Engineering, University of Nottingham, UK. Electronic address: bryan.stuart@materials.ox.ac.uk.
² School of Chemistry and Biosciences, University of Bradford, BD7 1DP, UK.
³ National Institute of Materials Physics, Magurele, Ilfov, Romania.
⁴ National Institute of Materials Physics, Magurele, Ilfov, Romania; Army Centre for Medical Research, RO-010195 Bucharest, Romania.
⁵ School of Chemistry, University of Nottingham, UK.
⁶ Advanced Materials Research Group, Faculty of Engineering, University of Nottingham, UK.

PMID: 29656232
DOI: 10.1016/j.jmbbm.2018.03.041

Abstract

The osteogenic ions Ca²⁺, P⁵⁺, Mg²⁺, and antimicrobial ion Ga³⁺ were homogenously dispersed into a 1.45 µm thick phosphate glass coating by plasma assisted sputtering onto commercially pure grade titanium. The objective was to deliver therapeutic ions in orthopaedic/dental implants such as cementeless endoprostheses or dental screws. The hardness 4.7 GPa and elastic modulus 69.7 GPa, of the coating were comparable to plasma sprayed hydroxyapatite/dental enamel, whilst superseding femoral cortical bone. To investigate the manufacturing challenge of translation from a target to vapour condensed coating, structural/compositional properties of the target (P51MQ) were compared to the coating (P40PVD) and a melt-quenched equivalent (P40MQ). Following condensation from P51MQ to P40PVD, P₂O₅ content reduced from 48.9 to 40.5 mol%. This depolymerisation and reduction in the P-O-P bridging oxygen content as determined by ³¹P NMR, FTIR and Raman spectroscopy techniques was attributed to a decrease in the P₂O₅ network former and increases in alkali/alkali-earth cations. P40PVD appeared denser (3.47 vs. 2.70 g cm^-3) and more polymerised than it's compositionally equivalent P40MQ, showing that structure/ mechanical properties were affected by manufacturing route.

Keywords: Antimicrobial; Coating; Osseointegration; Phosphate glass; Sputtering.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Gallium / chemistry*
Glass / chemistry*
Materials Testing*
Mechanical Phenomena*
Phosphates / chemistry*
Prostheses and Implants

Substances

Phosphates
Gallium