Biocompatibility property of 100% strontium‐substituted SiO₂–Al₂O₃–P₂O₅–CaO–CaF₂ glass ceramics over 26 weeks implantation in rabbit model: Histology and micro‐Computed Tomography analysis

Abstract

One of the desired properties for any new biomaterial composition is its long-term stability in a suitable animal model and such property cannot be appropriately assessed by performing short-term implantation studies. While hydroxyapatite (HA) or bioglass coated metallic biomaterials are being investigated for in vivo biocompatibility properties, such study is not extensively being pursued for bulk glass ceramics. In view of their inherent brittle nature, the implant stability as well as impact of long-term release of metallic ions on bone regeneration have been a major concern. In this perspective, the present article reports the results of the in vivo implantation experiments carried out using 100% strontium (Sr)-substituted glass ceramics with the nominal composition of 4.5 SiO2 -3Al2 O3 -1.5P2 O5 -3SrO-2SrF2 for 26 weeks in cylindrical bone defects in rabbit model. The combination of histological and micro-computed tomography analysis provided a qualitative and quantitative understanding of the bone regeneration around the glass ceramic implants in comparison to the highly bioactive HA bioglass implants (control). The sequential polychrome labeling of bone during in vivo osseointegration using three fluorochromes followed by fluorescence microscopy observation confirmed homogeneous bone formation around the test implants. The results of the present study unequivocally confirm the long-term implant stability as well as osteoconductive property of 100% Sr-substituted glass ceramics, which is comparable to that of a known bioactive implant, that is, HA-based bioglass.

Bone Regeneration by Novel Bioactive Glasses Containing Strontium and/or Magnesium: A Preliminary In-Vivo Study

“…The rabbit was selected since it is one of the most commonly used experimental animals. It is well known that the mid-diaphyseal bone is the preferred site for transcortical bulk implants by virtue of its mechanical and biological characteristics [23], whereas metaphyseal sites are preferred for analyzing spongy bone interactions with granular materials [18]. However, there are several reasons in our study for the choice of the mid-diaphyseal femur.…”

Micro-CT Analysis of Bone Healing in Rabbit Calvarial Critical-Sized Defects with Solid Bioactive Glass, Tricalcium Phosphate Granules or Autogenous Bone

“…Micro-computed tomography (micro-CT) serves as a new and accurate tool to analyze bone healing and to evaluate the bone formation on biomaterials such as TCP and BAG [ 20 , 21 ].…”

Influence of single and binary doping of strontium and lithium on in vivo biological properties of bioactive glass scaffolds

“…Moreover, Sr may enhance the ability of MSCs as well as pre-osteoblasts proliferation and differentiation into bone-forming osteoblasts59, through Wnt/b-catenin pathway by activating mitogenic signaling60. In a similar study using Sr doped HAp-based bioactive glasses implants, the sequential polychrome labeling of bone during in vivo osseointegration confirmed homogeneous bone formation around the test implants61.…”