Andrea Torroni1, Chongchen Xiang2, Lukasz Witek3, Eduardo D Rodriguez4, Paulo G Coelho5, Nikhil Gupta2. 1. Hansjörg Wyss Department of Plastic Surgery, New York University School of Medicine, New York, NY 10010, USA. Electronic address: andrea.torroni@nyumc.org. 2. Composite Materials and Mechanics Laboratory, Mechanical and Aerospace Engineering Department, New York University, Tandon School of Engineering, 6 MetroTech Center, Brooklyn, NY 11201, USA. 3. Department of Biomaterials, College of Dentistry, New York University, 433 1(st) Avenue, New York, NY 10010, USA. 4. Hansjörg Wyss Department of Plastic Surgery, New York University School of Medicine, New York, NY 10010, USA. 5. Hansjörg Wyss Department of Plastic Surgery, New York University School of Medicine, New York, NY 10010, USA; Department of Biomaterials, College of Dentistry, New York University, 433 1(st) Avenue, New York, NY 10010, USA.
Abstract
PURPOSE: Orthopedic and maxillofacial bone fractures are routinely treated by titanium internal fixation, which may be prone to exposure, infection or intolerance. Magnesium (Mg) and its alloys represent promising alternatives to produce biodegradable osteosynthesis devices, with biocompatibility and, specifically, hydrogen gas production during the degradation process, being the main drawback. Aim of this study is to test and compare biocompatibility, degradation rate and physiscochemical properties of two Mg-alloys to identify which one possesses the most suitable characteristics to be used as resorbable hardware in load-bearing fracture sites. MATERIALS AND METHODS: As-cast (WE43) and T5 Mg-alloys were tested for biocompatibility, physical, mechanical and degradation properties. Microstructure was assessed by optical microscopy, scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS); mechanical properties were tested utilizing quasi-static compression and failure analysis. Locoregional biocompatibility was tested by sub-periosteal implantation on the fronto-nasal region of large-animal model (sheep): regional immunoreaction and metal accumulation was analyzed by LA-ICP of tributary lymph-nodes, local reactions were analyzed through histological preparation including bone, implant and surrounding soft tissue. RESULTS: Mechanically, T5 alloy showed improvement in strength compared to the as-cast. Lymph-node Mg accumulation depicted no differences between control (no implant) and study animals. Both alloys showed good biocompatibility and osteogenesis-promoting properties. CONCLUSION: This study demonstrated excellent biocompatibility and osteogenesis-promoting capabilities of the tested alloys, providing a platform for further studies to test them in a maxillofacial fracture setting. T-5 alloy displayed more stability and decreased degradation rate than the as-cast.
PURPOSE: Orthopedic and maxillofacial bone fractures are routinely treated by titanium internal fixation, which may be prone to exposure, infection or intolerance. Magnesium (Mg) and its alloys represent promising alternatives to produce biodegradable osteosynthesis devices, with biocompatibility and, specifically, hydrogen gas production during the degradation process, being the main drawback. Aim of this study is to test and compare biocompatibility, degradation rate and physiscochemical properties of two Mg-alloys to identify which one possesses the most suitable characteristics to be used as resorbable hardware in load-bearing fracture sites. MATERIALS AND METHODS: As-cast (WE43) and T5 Mg-alloys were tested for biocompatibility, physical, mechanical and degradation properties. Microstructure was assessed by optical microscopy, scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS); mechanical properties were tested utilizing quasi-static compression and failure analysis. Locoregional biocompatibility was tested by sub-periosteal implantation on the fronto-nasal region of large-animal model (sheep): regional immunoreaction and metal accumulation was analyzed by LA-ICP of tributary lymph-nodes, local reactions were analyzed through histological preparation including bone, implant and surrounding soft tissue. RESULTS: Mechanically, T5 alloy showed improvement in strength compared to the as-cast. Lymph-node Mg accumulation depicted no differences between control (no implant) and study animals. Both alloys showed good biocompatibility and osteogenesis-promoting properties. CONCLUSION: This study demonstrated excellent biocompatibility and osteogenesis-promoting capabilities of the tested alloys, providing a platform for further studies to test them in a maxillofacial fracture setting. T-5 alloy displayed more stability and decreased degradation rate than the as-cast.
Authors: Matthew S Dargusch; Nagasivamuni Balasubramani; Nan Yang; Sean Johnston; Yahia Ali; Gui Wang; Jeffrey Venezuela; Jiwon Carluccio; Cora Lau; Rachel Allavena; Daniel Liang; Karine Mardon; Qingsong Ye Journal: Bioact Mater Date: 2021-10-23