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Porous degradable metallic biomaterials are attracting considerable attention as promising bone implant materials. Recently, the interest in developing new biomaterials with enhanced performance stimulates the widespread development of fabricating techniques for porous metals. In this work, the recent progress and novel trends on preparation methods of metallic foams for biomedicine were systematically reviewed. The common synthesis methods for porous Mg, Fe, Zn, and their alloys intended for orthopedic applications are comprehensively discussed and compared. The advantages and disadvantages of relevant manufacturing strategies are evaluated. While the modern techniques enable fabrication of complex porous structures and customized shapes, the cost-effective and easy controllable approach are major benefits of traditional methods. Main structural characteristics and properties of biomaterials fabricated using different routes are also presented. Furthermore, the future research directions and current challenges are mentioned. The ambition of this review article is to provide useful guidelines for researchers to choose suitable manufacturing technique to prepare materials with desired structural topology and mechanical, and degradation properties.

Zn-Fe alloys have been extensively investigated in this study with a view to their application as biodegradable bone implants. Biogenic element zinc is a very appropriate metal because of the ideal degradation rate compared to those of Mg and Fe. Studied alloys were made by compressing metallic powders in a content ratio of 100% Zn, Zn-1% Fe, Zn-2% Fe, Zn-5% Fe and Zn-10% Fe and sintering at 350 ​°C for 1 ​h. Prepared samples were examined by optical microscopy, SEM and XRD. Corrosion behavior, mechanical testing and hemocompatibility were observed subsequently. The electrochemical performance of such materials was studied in the simulated body fluids. The enhanced corrosion rate was observed for all samples after iron addition due to the micro-galvanic effect between the pure Zn and Zn11Fe intermetallic phase. The corrosion rate of the Zn-5% Fe alloyed sample was more than 20-times higher (2.89 mmpy) compared to the pure Zn. However, alloying with more than 5 ​wt % of iron diminished the mechanical performance of the material. Therefore, the performed mechanical and hemocompatibility tests showed acceptable biocompatibility of zinc and Zn-1% Fe and Zn-2% Fe samples.

Advances in biomedicine and development of modern technologies in the last century have fostered the improvement in human longevity and well-being. This progress simultaneously initiated the need for novel biomaterials. Recently, degradable metallic biomaterials have attracted serious attention in scientific and clinical research owing to their utilization in some specific applications. This work investigates the effect of the polyethylene glycol (PEG) coating of open-cell iron and phosphorus/iron foams on their microstructure and corrosion properties. The addition of phosphorus causes a slight increase in pore size and the deposition of a polymer coating results in a smoothened surface and a moderate decrease in pore diameter. The PEG coating leads to an increase in corrosion rates in both foams and potentially a more desirable product.