Surface-Modified Drug Eluting Magnesium-Based Biodegradable Porous Scaffold for Treating Bone Defects

Magnesium(Mg)-based biodegradable porous scaffolds are gaining extensive attention as promising bone substitutes for treating bone defects. Porous scaffolds offer more suitable interconnection to surrounding bone tissues than solid implants. Assessing biodegradation, biocompatibility, and bone regeneration ability of Mg-based scaffolds is very crucial for validating their ability for bone regeneration. Inherent electrochemical active properties of Mg necessitate achieving an optimal in-service degradation rate to retain its mechanical integrity in a physiological environment. In this study, Mg–3Zn-based porous scaffolds have been fabricated via spark plasma sintering employing a salt leaching technique. Further, a hybrid layer coating was applied on a Mg–3Zn scaffold to enhance its degradation resistance and biofunctionality. The hybrid layer coating on Mg–3Zn scaffolds, incorporated with 1.5 wt % hydroxyapatite, enhanced compressive strength and toughness by ∼65% and ∼110%, respectively, as compared to the uncoated scaffold. Additionally, in vivo studies revealed a significant improvement in the bone regeneration ability of the coated scaffold after 28 days of implantation in rat models. Radiological examinations of implanted scaffolds confirmed a controlled degradation rate in vivo. Histological evaluations of harvested vital organs like liver, kidney, and heart showed no toxicity. The fabricated surface-modified scaffolds possess superior biomechanical and biodegradation (in vitro and in vivo), rendering them potentially helpful in treating bone defects.