Enhanced biocompatibility and osseointegration of calcium titanate coating on titanium screws in rabbit femur

Abstract

This study aimed to examine the biocompatibility of calcium titanate (CaTiO) coating prepared by a simplified technique in an attempt to assess the potential of CaTiO coating as an alternative to current implant coating materials. CaTiO-coated titanium screws were implanted with hydroxyapatite (HA)-coated or uncoated titanium screws into medial and lateral femoral condyles of 48 New Zealand white rabbits. Imaging, histomorphometric and biomechanical analyses were employed to evaluate the osseointegration and biocompatibility 12 weeks after the implantation. Histology and scanning electron microscopy revealed that bone tissues surrounding the screws coated with CaTiO were fully regenerated and they were also well integrated with the screws. An interfacial fibrous membrane layer, which was found in the HA coating group, was not noticeable between the bone tissues and CaTiO-coated screws. X-ray imaging analysis showed in the CaTiO coating group, there was a dense and tight binding between implants and the bone tissues; no radiation translucent zone was found surrounding the implants as well as no detachment of the coating and femoral condyle fracture. In contrast, uncoated screws exhibited a fibrous membrane layer, as evidenced by the detection of a radiation translucent zone between the implants and the bone tissues. Additionally, biomechanical testing revealed that the binding strength of CaTiO coating with bone tissues was significantly higher than that of uncoated titanium screws, and was comparable to that of HA coating. The study demonstrated that CaTiO coating in situ to titanium screws possesses great biocompatibility and osseointegration comparable to HA coating.

Implant‐bone‐interface: Reviewing the impact of titanium surface modifications on osteogenic processes in vitro and in vivo

“… 98 The results after 12 weeks of implantation were comparable to HAp‐coated and superior to uncoated implants. 98 Ca 2+ deposition in a nano‐porous Ti alloy equally resulted in improved osteoconductivity and overall bone formation at week four and eight after implantation in a rat femur compared to Na + incorporation. The divalent Ca 2+ incorporates deeper into the layer of the nano‐porous structure, enabling a consistent and sustained release over time, leading to a superior bioactivity and increased trabecular bone formation.…”

“…For example, the incorporation of calcium ions (Ca 2+ ) into the titanium surface enabled the conversion of passive oxide into a bioactive oxide (CaTiO 3 ), which is more favorable for biological interaction. Wang et al reported excellent biocompatibility and osteointegration effects of nano‐bioactive CaTiO 3 coated screws produced via treatment with NaOH and CaCl 2 98 . The results after 12 weeks of implantation were comparable to HAp‐coated and superior to uncoated implants 98 .…”

“…Wang et al reported excellent biocompatibility and osteointegration effects of nano‐bioactive CaTiO 3 coated screws produced via treatment with NaOH and CaCl 2 98 . The results after 12 weeks of implantation were comparable to HAp‐coated and superior to uncoated implants 98 . Ca 2+ deposition in a nano‐porous Ti alloy equally resulted in improved osteoconductivity and overall bone formation at week four and eight after implantation in a rat femur compared to Na + incorporation.…”

In Vitro and In Vivo Biocompatibility Studies of a Cast and Coated Titanium Alloy

“…In contrast to a coating with hydroxyapatite, which does not form an intimate connection with the titanium and shows delamination and unpredictable biodegradation [ 70 , 71 , 72 ], with the consequence of loose implants, the calcium titanate even preserves the surface architecture and roughness of the implant [ 73 ]. Several authors describe the benefit of a calcium titanate layer on titanium implants in cell culture experiments [ 31 , 74 , 75 , 76 , 77 ], in femoral condyle [ 77 , 78 ], and tibia [ 73 ] of rabbits. Unfortunately, we do not see any significant differences in our experiments between the coated and uncoated implants.…”

Prospect of Metal Ceramic (Titanium-Wollastonite) Composite as Permanent Bone Implants: A Narrative Review

“…Biocompatibility has been the gold standard for any type of implant be it metal, ceramic or even polymer. Another study using calcium titanate coating on titanium screws has also demonstrated the biocompatibility of the material such that it has excellent synergistic properties with osteoblastic cells [ 134 ]. Here we can summarise that knowing and identifying whether metal-ceramics are biocompatible represents a crucial first step for the material to be identified as a biomaterial.…”