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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.

Biodegradable materials suitable for medical application with improved corrosion resistance and good biocompatibility along with enhanced mechanical properties are the need of the hour. Such properties in Mg-Zn-Ca glass forming alloy used as a metal matrix can be obtained through proper reinforcement. Hydroxyapatite (HA) which is a mineral constituent of natural bone has a wide range of medical applications because of its excellent biocompatibility and bioactivity. They promote bone cell adhesion and osteoblastic proliferation. In the present study, the influence of HA particle (HA p ) addition on the glass forming ability, corrosion resistance, mechanical behavior and cytocompatibility of Mg 66 Zn 30 Ca 4 alloy has been investigated. The addition of HA p decreases the glass forming ability of Mg 66 Zn 30 Ca 4 alloy. Significant improvement in corrosion resistance along with marginal improvement in mechanical properties is observed upon addition of HA p . Moreover, HA p incorporation into Mg 66 Zn 30 Ca 4 metallic glass has enhanced the cell viability and cell adhesion of human osteoblast-like cell (MG63) cells, complementing the excellent biocompatibility, bioactivity, osteoconductivity and osteoinductivity of hydroxyapatite mineral due to its biomimetic nature. HA reinforcement is not only a promising approach to improve the corrosion resistance, but also offers a biomimitic interface to enhance osseointegration and overall competence of orthopedic implants.

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