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Characterization and in vitro evaluation of biphasic calcium pyrophosphate–tricalciumphosphate radio frequency magnetron sputter coatings
Author(s) -
Takahashi K.,
van den Beucken J.J.J.P.,
Wolke J.G.C.,
Hayakawa T.,
Nishiyama N.,
Jansen J.A.
Publication year - 2007
Publication title -
journal of biomedical materials research part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.849
H-Index - 150
eISSN - 1552-4965
pISSN - 1549-3296
DOI - 10.1002/jbm.a.31341
Subject(s) - materials science , bioceramic , simulated body fluid , calcium pyrophosphate , scanning electron microscope , dissolution , amorphous solid , osteocalcin , osteoblast , chemical engineering , calcium , amorphous calcium phosphate , nuclear chemistry , mineralogy , composite material , in vitro , metallurgy , alkaline phosphatase , biochemistry , chemistry , crystallography , enzyme , engineering
Abstract The objective of this study was to characterize the physicochemical, dissolution, and osteogenic properties of radio frequency magnetron sputtered dicalcium pyrophosphate/tricalciumphosphate (Pyro/TCP) and hydroxylapatite (HA) coatings. Therefore Pyro/TCP and HA coatings were deposited on grit‐blasted titanium discs. The results showed that the deposited coatings were amorphous and changed into a crystalline structure after IR heat‐treatment of 550°C for HA and 650°C for Pyro/TCP. Heat‐treated HA coatings appeared to be stable during immersion in simulated body fluid (SBF), that is no changes in the XRD pattern were observed. Also, no dissolution of the coating was observed by scanning electron microscopy (SEM). Energy dispersive spectroscopy (EDS) revealed that the Ca/P ratio of the HA coatings remained constant during SBF immersion. On the other hand, the heat‐treated Pyro/TCP coatings showed a surface reaction of calcium pyrophosphate into a β‐tricalcium phosphate phase during SBF immersion. This was confirmed by EDS analysis. Rat bone marrow‐derived osteoblast‐like cells cultured on the heat‐treated substrates showed that cell proliferation and differentiation occurred on both types of bioceramic coatings. No significant differences for proliferation and early differentiation were observed between cells cultured on heat‐treated Pyro/TCP and HA at individual time points. However, osteocalcin expression, a late marker for osteoblast‐like cell differentiation, was significantly increased after 12 days of culture on HA‐coatings. These results were confirmed by SEM observations and suggest increased osteogenic properties for HA‐coatings over Pyro/TCP‐coatings. Additional research is necessary to obtain conclusive evidence on the in vivo osteogenic capacity of Pyro/TCP coatings. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008