The results indicated that the degradation rate of the Mg specimen in the cell culture medium was significantly accelerated with increased surface roughness. Three representative scales of surface roughness were investigated in this study, including smooth (Sa 2.0 µm). Nevertheless, the most optimized surface roughness has been questionable, especially for Mg-based oral and maxillofacial implants. Appropriate surface roughness plays a critical role in the degradation behavior and the related cellular processes of biodegradable Mg-based metals. High-purity magnesium (Mg) is a promising biodegradable metal for oral and maxillofacial implants. This study showed that pure Zn porous scaffolds with customized structures fabricated using L-PBF represent a promising biodegradable solution for treating large bone defects. Moreover, the pure Zn porous scaffold showed good biocompatibility and osteogenic promotion ability in vivo. A benign host response was observed using hematoxylin and eosin (HE) staining of the heart, liver, spleen, lungs, and kidneys. The results showed that the pure Zn porous scaffolds had compressive strength and rigidity comparable to those of cancellous bone, as well as relatively suitable degradation rates for bone regeneration. The scaffolds were then implanted into the rabbit femur critical-size bone defect model for 24 weeks. First, the mechanical properties, corrosion behavior, and biocompatibility of the pure Zn porous scaffolds were characterized in vitro. In this study, pure Zn porous scaffolds with diamond structures were fabricated using customized laser powder bed fusion (L-PBF) technology. Biodegradable Zn metals are revolutionary materials for orthopedic implants. In addition, three in vivo implantation models were explored in rats: subcutaneous, aorta, and femoral implantations, to target the potential clinical applications of bioresorbable Zn implants.Īdditive manufacturing has received attention for the fabrication of medical implants that have customized and complicated structures. Our study showed the first evidence that blending with transition metals V, Cr, or Zr can improve Zn's properties as bioresorbable medical implants. Furthermore, the biosafety of these elements is of less concern as they all have been used as regulatory approved medical implants or a component of an implant such as Ti6Al4V, CoCr, or Zr-based dental implants. These selected transition metals have similar properties to Zn and thus are beneficial for the metallurgy process and mechanical property.

Hereby, we proposed to blend selective transition metals (i.e., vanadium-V, chromium-Cr, and zirconium-Zr) to improve Zn's properties. Still, the choice of alloying element is crucial to ensure the resulting alloy possesses sufficient mechanical strength, suitable degradation rate, and acceptable biocompatibility. Alloying is the most common/effective way to overcome this limitation.

However, pure Zn is not ideal for these applications due to its low mechanical strength and localized degradation behavior. Zinc (Zn) is a new class of bioresorbable metal that has potential for cardiovascular stent material, orthopedic implants, wound closure devices, etc.

Metal reactivity series