In vitro and in vivo evaluation of novel biodegradable Mg‐Ag‐Y alloys for use as resorbable bone fixation implant

Abstract

Magnesium (Mg) alloy is gaining more interest because of its degradability and osteogenic potential. Still, it has some deficiencies, such as its rapid degradation rate, insufficient mechanical property. This research aimed to design a novel biodegradable Mg-argentum (Ag)-yttrium (Y) alloy, and Y was added to improve degradable and mechanical property. Mg-Ag-Y alloys were characterized for mechanical features, practicabilities in vitro and in vivo. The mechanical features results shown that this novel component was similar to native bone tissue in elastic moduli, tensile, and compressive stress. Then mesenchymal stem cells (MSCs) were seeded in alloys to assess cell toxicity in vitro. The results showed that its aqueous extract was suitable for MSCs adhesion and proliferation. Then the alloy was evaluated for biomedical applications in nonfractured distal femora of Sprague Dawley rats for 6 weeks, compared with those of pure-Mg and stainless steel groups. All rats survived, and hematological and histological evaluation showed no abnormal physiology 6 weeks postimplantation, and measurements of serum Mg concentration were within normal levels. X-ray scanning, microcomputed tomography, and histological examinations were performed to evaluate the degradability and osteogenic potential. The results indicated that the degradation rate of alloy was 0.91 mm per year, (range 0.77-1.22 mm), and pure-Mg 1.80 mm per year (1.43-2.26 mm). The new bone quantity was 3.18 mm (1.46-4.44 mm ) in Mg-Ag-Y alloys group, 1.39 mm (0.54-2.32 mm ) in pure-Mg group, and none in stainless steel group. These promising results suggest potential clinical application of Mg-Ag-Y alloys for use as resorbable bone fixation implant. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 2059-2069, 2018.

In vivo evaluation of bending strengths and degradation rates of different magnesium pin designs for oral stapler

“…11 The alkalinity induced by abundant hydroxides and hydrogen might also damage the surrounding tissue. 20 However, no obvious inflammation or systemic adverse reaction was observed in this study.…”

“…Magnesium matrix materials have been widely studied in many medical fields. 7,15–18 Mg implants have been made to evaluate the treatment of patients using Mg medical devices in bone and ligament healing, 19–21 gastrointestinal anastomosis, 22 biliary tract anastomosis, 16 cardiovascular stents, 17,18 laryngeal applications, 23 compressed sciatic nerves repair, 24 and so on. For example, in bone surgery, Han et al proved that a high-purity Mg screw showed good osseointegration and increased bone mineral density and thus has great potential for internal fixation devices in intra-articular fracture operations.…”

“…25 Yu et al suggested a potential clinical application of Mg–Ag–Y alloy rods for use as a resorbable bone fixation implant. 20 Magnesium wires have also been reported as being tried in bone fixation and nerves/muscle suture. 7,8 In cardiovascular surgery, Moravej and Mantovani showed that the role of stenting is temporary and limited to a period of 6–12 months after implantation, 17 and magnesium is a potential alternative material for the currently used permanent cardiovascular stents.…”

In vitro and in vivo biological performance of Mg-based bone implants

“…The use of REE as alloying elements is controversial from a medical point of view but elements such as Y, Nd, Gd can improve the strength, ductility and corrosion resistance of the material. Yu et al (2018) assessed the in vivo corrosion behaviour and osteogenic potential of a novel Mg-Ag-Y alloy and observed that the corrosion rate of the alloying system was significantly lower and more bone tissue was formed around the implant in comparison to pure Mg, mostly due to the presence of the Y element. Also, using Y as an alloying element, Chou et al (2019) evaluated the in vivo performance of a Mg-Y-Zn-Zr-Ca alloy and reported positive results regarding its biocompatibility but poor corrosion resistance due to the surrounding blood vessels and stress related corrosion that appeared at the osteotomy site of high mechanical loading.…”

Degradation Behaviour of Mg0.6Ca and Mg0.6Ca2Ag Alloys with Bioactive Plasma Electrolytic Oxidation Coatings

“…Regarding magnesium alloys containing Ag, their antibacterial effect has been reported for a wide range of the microbial spectrum [22]. However, problems of high corrosion rates [16] and cytotoxicity [23] have also been found, although the cytotoxicity can be decreased while maintaining the antimicrobial effect if a secondary element, such as calcium, is included in the alloy [19].…”