Bone Response to Porous Alumina Implants Coated with Bioactive Materials, Observed Using Different Characterization Techniques

Abstract

Background Implants or implantable devices should integrate into the host tissue faster than fibrous capsule formation, in which the design of the interface is one of the biggest challenges. Generally, bioactive materials are not viable for load-bearing applications, so inert biomaterials are proposed. However, the surface must be modified through techniques such as coating with bioactive materials, roughness and sized pores. The aim of this research was to validate an approach for the evaluation of the tissue growth on implants of porous alumina coated with bioactive materials. Methods Porous alumina implants were coated with 45S5 Bioglass® (BG) and hydroxyapatite (HA) and implanted in rat tibiae for a period of 28 days. Ex vivo resections were performed to analyze osseointegration, along with histological analysis, Scanning Electron Microscopy with Energy Dispersive X-Ray spectroscopy (SEM-EDX) line scanning, radiography and biomechanical testing. Results Given that the process of implant integration needs with the bone tissue to be accelerated, it was then seen that BG acted to start the rapid integration, and HA acted to sustaining the process. Conclusions Inert materials coated with bioglass and HA present a potential for application as bone substitutes, preferably with pores of diameters between 100 μm and 400 μm and, restrict for smaller than 100 μm, because it prevents pores without organized tissue formation or vacant. Designed as functional gradient material, stand out for applications in bone tissue under load, where, being the porous surface responsible for the osseointegration and the inner material to bear and to transmit the loads.

Scaffold Structural Microenvironmental Cues to Guide Tissue Regeneration in Bone Tissue Applications

“…Scaffolds in tissue engineering ought to act as the temporary extracellular matrix to provide supports for cells and guide cell differentiation [ 16 , 17 , 18 ]. Porous bioactive materials are designed to mimic the properties of in vivo environment [ 19 ]. Their porosity and pore size are crucial in determining biological functions.…”

Modification of silicone elastomers with Bioglass 45S5® increases in ovo tissue biointegration

“…As for the vascularization of the CAM below the scaffolds, we found a higher vessel density for pure silicone as compared with the BG‐containing materials which were both similarly vascularized. It might be speculated whether the Bioglass or its transformation product hydroxyapatite decreased the angiogenic response toward the BG/silicone scaffolds—the two components have been reported to act differently toward neovascularization …”

Role of implants surface modification in osseointegration: A systematic review

“…It is also found to have an excellent combination of material toughness and yield strength, ductility, and hardness (Navarro, Michiardi, Castaño, & Planell, 2008). Cobalt increases the strength of alloy, whereas chromium is a component that enhances the corrosion resistance (Camilo et al, 2017). However, adding more than 30% chromium makes this alloy hard to cast and results in a brittle phase (Christian, Oliver, Paustenbach, Kreider, & Finley, 2014 but also found to be electrochemically equivalent after multiple castings (Viennot, Dalard, Lissac, & Grosgogeat, 2005).…”