Antibacterial, angiogenic, and osteogenic activities of Ca, P, Co, F, and Sr compound doped titania coatings with different Sr content

Jianhong Zhou,Lingzhou Zhao,Xiaoli Wang

doi:10.1038/s41598-019-50496-3

Jianhong Zhou, Lingzhou Zhao + Show 1 more

Open Access

https://doi.org/10.1038/s41598-019-50496-3

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Abstract

Titanium implants are often combined with microporous titania coatings simultaneously doped with various elements to enhance their antibacterial, angiogenic and osteogenic activities. To evaluate how Sr doping levels affect properties of titania coatings simultaneously doped with Ca, P, Co and F (TiCPCF coatings), we prepared coatings with Sr contents equal to 6, 11 and 18 wt% (TiCPCF-S6, TiCPCF-S11 and TiCPCF-S18, respectively) using micro-arc oxidation of titanium. Sr presence in TiCPCF coatings did not affect their phase compositions, microstructure, surface wettability, roughness, and adhesion to titanium. Antibacterial, angio- and osteo-genic activities of all the coatings were evaluated. Sr incorporation improved mesenchymal stem cell proliferation, osteogenic differentiation and implant osseointegration. TiCPCF-S11 showed the most optimum Sr content judging by its enhanced osteogenic activity. While Sr incorporation did not weaken angiogenic and antibacterial abilities of TiCPCF. Thus TiCPCF-S11 coating is a very strong candidate to be used as a next-generation bone implant material.

Highlights

Titanium (Ti) is a popular metal used for fabrication of body implants because of its excellent mechanical performance and biocompatibility[1]
Sr content in coatings was adjusted by using different strontium acetate concentration in micro-arc oxidation (MAO) electrolytes: the more Sr was in the electrolyte, the higher its content was in the coating
Our previous study found that co-incorporation of Sr, Co and F into TiO2 coatings already containing Ca and P can lead to better osteogenic, angiogenic, and antibacterial activities[14] of the resulting coatings

Summary

Introduction

Titanium (Ti) is a popular metal used for fabrication of body implants because of its excellent mechanical performance and biocompatibility[1]. Incorporation of inorganic bioactive elements with slow delivering speeds provides implants with necessarily and needed enhanced antibacterial, angiogenic and osteogenic abilities. These additives should be stable and must enhance their incorporation with high efficiency even at low concentrations. We implemented micro-arc oxidation (MAO), which, when used to incorporate inorganic dopants into metallic Ti implant surfaces, yields rough, strongly adhering and bioactive titania (TiO2)-based coatings[12,13]. Our previous works showed that incorporation of Sr, Co, F, Ca and P into TiO2 coating results in better osteogenic and angiogenic as well as antibacterial activities[14], and have optimized the F6 and Co9 contents in the coatings. Bone marrow MSCs from New Zeland rabbits, Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) bacteria were implemented to analyze antibacterial, angio- and osteo-genic properties of these coatings both in vitro and in vivo

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