RESUMO
Magnesium (Mg) alloy-based porous bio-nanocomposite bone scaffolds were developed by powder metallurgy route. Selective alloying elements such as calcium (Ca), zinc (Zn) and strontium (Sr) were incorporated to tune the mechanical integrity while, bioactive fluorcanasite nano-particulates were introduced within the alloy system to enhance the bone tissue regeneration. Green compacts containing carbamide were fabricated and sintered using two-stage heat treatment process to achieve the targeted porosities. The microstructure of these fabricated magnesium alloy-based bio-nanocomposites was examined by Field emission scanning electron microscope (FE-SEM) and x-ray micro computed tomography (x-ray µCT), which revealed gradient porosities and distribution of alloying elements. X-ray diffraction (XRD) studies confirmed the presence of major crystalline phases in the fabricated samples and the evolution of the various combinations of intermetallic phases of Ca, Mg, Zn and Sr which were anticipated to enhance the mechanical properties. Further, XRD studies revealed the presence of apatite phase for the immersed samples, a conducive environment for bone regeneration. The fabricated samples were evaluated for their mechanical performance against uniaxial compression load. The tunability of compressive strengths and modulus values could be established with variation in porosities of fabricated samples. The retained compressive strength and Young's modulus of the samples following immersion in phosphate buffered saline (PBS) solution was found to be in line with that of natural human cancellous bone, thereby establishing the potential of the fabricated magnesium-alloy-based nanocomposite as a promising scaffold candidate for bone tissue engineering.
