WE43 and WE43-T5 Mg alloys screws tested in-vitro cellular adhesion and differentiation assay and in-vivo histomorphologic analysis in an ovine model

Abstract

WE43 Mg alloy proved to be an ideal candidate for production of resorbable implants in both clinical and trial settings. In previous studies we tested biocompatibility and degradation properties of WE43 (as-cast) and artificially aged (WE43-T5) Mg alloys in a sheep model. Both alloys showed excellent biocompatibility with the as-cast, WE43, form showing increased degradability compared to the artificially aged, WE43-T5. In the present study, our group assessed the biological behavior and degradation pattern of the same alloys when implanted as endosteal implants in a sheep model. Twelve screws (3x15 mm) were evaluated, one screw per each composition was placed bi-cortically in the mandible of each animal with a titanium (2x12 mm) screw serving as an internal positive control. At 6 and 24 weeks histomorphological analysis was performed, at 6 weeks as cast, WE43, yielded a higher degradation rate, increased bone remodeling and osteolysis compared to the WE43-T5 alloy; however, at 24 weeks WE43-T5 showed higher degradation rate and increased bone remodeling than as-cast. In vitro assay of cell growth, adhesion and differentiation was also conducted to investigate possible mechanisms underlying the behavior expressed from the alloys in vivo. In conclusion WE43-T5 indicated bone/implant interaction properties that makes it more suitable for fabrication of endosteal bone screws.

Bioresorbable Magnesium-Based Alloys as Novel Biomaterials in Oral Bone Regeneration: General Review and Clinical Perspectives

“…The detailed pre-clinical studies of these alloys were summarized in Table 1. [52] pin Rat femoral bones 7 days 0.15 ± 0.03 mm/y 26 Mg enriched (>99 wt.%) [53] pin Rat femoral bones 4, 24, 52 weeks 16 ± 5 µm/y Pure Mg high pressure (99.98 Mg in wt.%) [54] disk Rat femoral bones 24 weeks 0.41 ± 0.02 mm/y WE43 (>92.0 Mg in wt.%) [55] plates and screw Dogs-LeFort I osteotomy 4, 12, and 24 weeks NA 1 WE43 (>92.0 Mg in wt.%) [56] screw Rabbit tibiae 4, 8, 12 and 16 weeks NA 1 WE43 (>92.0 Mg in wt.%) [57] pin Rat tibiae 52 weeks NA 1 WE43/WE43T5 (>92.0 Mg in wt.%) [58] screw Sheep mandibule 6 and 24 weeks NA 1 MgYREZr (>92.0 Mg in wt.%) [59] screw Rabbit femoral bones 1, 12, and 52 weeks NA 1 JDBM (>95.0 Mg in wt.%) [60] screw Rabbit mandible bones 1, 4, and 7 months 0.161 ± 0.025 mm/y (1 month), 00.218 ± 0.030 mm/y (7 months) NZK (>96.0 Mg in wt.%) [61] rod Rabbit femoral bones 28 and 56 days 0.66 mm/y (28 days) and 0.48 mm/y (56 days) Mg-Zn (94.0 Mg in wt.%) [62] rod Rabbit femoral bones 14 weeks 2.32 mm/y ZX00 (>99.0 Mg in wt.%) [63] pin Rat femoral bones and sheep tibiae 6, 12 and 24weeks 0.08 mm/y (rat) and 0.045 mm/y (sheep) ZX00 (>99.0 Mg in wt.%) [64] screw Sheep tibiae 3, 6 and 12 weeks NA 1…”

“…At 24 weeks, histomorphological analysis showed that WE43-T5 alloy had higher degradation rate and enhanced bone remodelling compared to WE43 (as-cast). Therefore, the developed WE43-T5 alloy is a suitable candidate as an endosteal bone screw [ 58 ]. Another in vivo study carried out by Byun et al concluded that extruded WE43 was suitable to be used for mid-facial application.…”

In Silico Biomechanical Evaluation of WE43 Magnesium Plates for Mandibular Fracture Fixation

“…Therefore, magnesium regained relevance for clinical use in load-bearing applications of reconstructive and trauma surgery. Several in vivo preclinical studies successfully observed new bone deposition around WE43 plates and screws (Schaller et al, 2016;Naujokat et al, 2017;Byun et al, 2020;Imwinkelried et al, 2020;On et al, 2020;Rendenbach et al, 2021;Torroni et al, 2021) and a preserved structural integrity in the first 12 weeks of the healing process (Marukawa et al, 2016;Levorova et al, 2018). However, to date, only Leonhardt et al (Leonhardt et al, 2017;Leonhardt et al, 2021) reported a clinical application of magnesium-based lag screws for mandibular condylar head fracture fixation.…”

Mimicking 3D bone microenvironment using a hybrid hydrogel-nanocomposite scaffold and human adipose-derived stem cells for bone differentiation and vascularization

“…This is in keeping with current trends in tissue engineering that use biomaterials to facilitate autologous tissue engineering in vivo. The use of bioceramic, alloy and nanomaterial implants to promote bone regeneration using the in vivo environment as a bioincubator has already shown promise in animal fracture repair models [84,85].…”