The effects of plasma electrolytically oxidized layers containing Sr and Ca on the osteogenic behavior of selective laser melted Ti6Al4V porous implants

The effects of plasma electrolytically oxidized layers containing Sr and Ca on the osteogenic behavior of selective laser melted Ti6Al4V porous implants

van Hengel, I.A.J. (TU Delft Biomaterials & Tissue Biomechanics)
Lacin, M. (TU Delft Biomaterials & Tissue Biomechanics)
Minneboo, M.B. (TU Delft Biomaterials & Tissue Biomechanics)
Fratila-Apachitei, E.L. (TU Delft Biomaterials & Tissue Biomechanics)
Apachitei, I. (TU Delft Biomaterials & Tissue Biomechanics)
Zadpoor, A.A. (TU Delft Biomaterials & Tissue Biomechanics)

2021

Surface biofunctionalization is frequently applied to enhance the functionality and longevity of orthopedic implants. Here, we investigated the osteogenic effects of additively manufactured porous Ti6Al4V implants whose surfaces were biofunctionalized using plasma electrolytic oxidation (PEO) in Ca/P-based electrolytes with or without strontium. Various levels of Sr and Ca were incorporated in the oxide layers by using different current densities and oxidation times. Increasing the current density and oxidation time resulted in thicker titanium oxide layers and enhanced the release of Ca²⁺ and Sr²⁺. Biofunctionalization with strontium resulted in enhanced pore density, a thinner TiO₂ layer, four-fold reduced release of Ca²⁺, and mainly anatase phases as compared to implants biofunctionalized in electrolytes containing solely Ca/P species under otherwise similar conditions. Different current densities and oxidation times significantly increased the osteogenic differentiation of MC3T3-E1 cells on implants biofunctionalized with strontium, when the PEO treatment was performed with a current density of 20 A/dm² for 5 and 10 min as well as for a current density of 40 A/dm² for 5 min. Therefore, addition of Sr in the PEO electrolyte and control of the PEO processing parameters represent a promising way to optimize the surface morphology and osteogenic activity of future porous AM implants.

Additive manufacturing
Current density
Oxidation time
Plasma electrolytic oxidation
Strontium
Surface biofunctionalization
Titanium bone implants

http://resolver.tudelft.nl/uuid:46da4e7e-b871-4662-8667-5bed5dc79f34

https://doi.org/10.1016/j.msec.2021.112074

0928-4931

Materials Science and Engineering C: Materials for Biological Applications (online), 124

Institutional Repository

journal article

© 2021 I.A.J. van Hengel, M. Lacin, M.B. Minneboo, E.L. Fratila-Apachitei, I. Apachitei, A.A. Zadpoor