Improved osteogenic activity of NiTi orthopedic implant by HAp-Nb2O5 composite coatings: Materials and biological points of view

Encouraging tribomechanical and biological responses of hydroxyapatite coatings reinforced by various levels of niobium pentoxide particles

“…40 It has been shown that the presence of this phase, at low amounts, besides HAp, is beneficial for improved in vivo biomineralization and biocompatibility. 32…”

“…The presence of enough hydroxyl ions together with enough time are two required factors for the mentioned transformation. 32 The reason for the presence of strong Nb 2 O 5 diffractions is using an X-ray beam with a low incident angle, which determines the phase structure of the outermost layers of the coatings.…”

“…The (i) polar OH groups of the top HAp layer and (ii) ionic character of the deposited ceramic coating led to an increase in the wettability of NiTi. 32 The contact angle between the SBF drop and the coated samples increased with the inclusion of the Nb 2 O 5 particles due to the fact that the particles regionally prevented the water molecules from penetrating the surface. Optimizing surface wettability is a key strategy to achieving the most appropriate biological responses.…”

“…Details of the sterilization process are reported in our previous paper. 32 The sterilized specimens were located in a 12-well cell culture plate, then the cells with a density of 2 × 10 5 cells per mL were seeded on their surface.…”

“…Nb 2 O 5 particles seem to be an appropriate candidate to promote the tribomechanical properties and biocompatibility of the electrodeposited HAp coatings due to their illustrious resistance against both wear and corrosion, high stability, magnificent mechanical strength (elastic modulus of over 100 GPa), and striking bioactivity and biocompatibility. 32–36…”