BIC - Biodegradable Metals for Interbody Cage: Biodegradation, Biocompatibility and Biomechanics

• Grant number: 25/02908-7
• Support Opportunities: Regular Research Grants
• Start date: August 01, 2025
• End date: July 31, 2027
• Field of knowledge: Engineering - Materials and Metallurgical Engineering
• Mobility Program: SPRINT - Projetos de pesquisa - Mobilidade
• Principal Investigator: Ana Paula Rosifini Alves
• Grantee: Ana Paula Rosifini Alves
• Principal researcher abroad: Marta María Multigner Domínguez
• Institution abroad: Universidad Rey Juan Carlos, Móstoles (URJC), Spain
• Host Institution: Faculdade de Engenharia (FEG). Universidade Estadual Paulista (UNESP). Campus de Guaratinguetá. Guaratinguetá , SP, Brazil
• Associated researchers: Pedro Yoshito Noritomi
• Associated research grant: 22/14790-2 - Biomimetic spine fusion implants for back pain (BioFusion), AP.TEM

Abstract

Orthopedic issues affect millions of people due to factors such as aging, diseases like osteoporosis, and accidental injuries. The materials commonly used for interbody fusion cages can be categorized into metallic and non-metallic types. The most frequently used interbody cages are made from non-absorbent materials, such as titanium (Ti) and poly-ether-ether-ketone (PEEK). However, titanium alloys may lead to implant subsidence and segmental instability due to their high elastic modulus, which causes stress shielding. On the other hand, the use of PEEK is limited by its poor biocompatibility, which can trigger chronic inflammatory responses. Absorbable materials include magnesium (Mg) and other polymer materials. With the mechanical strength weakening due to degradation, the materials may not be able to provide sufficient support, leading to interbody fusion failure. Despite recognizing their potential benefits, there are still limited choices of biodegradable materials, and researchers are continuously exploring new types of materials or improving the existing ones to achieve the desired functionality. Therefore, it is necessary to explore new materials that promote interbody fusion. Metals such as Zn and Fe and their alloys are the most widely studied degradable metallic biomaterials. Alongside exploring new biodegradable materials, biodegradable patient-specific implants can be developed using 3D printing technologies, such as binder/ink-jetting, material extrusion, and selective laser melting. These methods enable the creation of customized biodegradable scaffolds designed to address the specific needs of various treatment conditions. 3D printing is becoming a technology that can support the transition from a linear economy to a circular economy in the manufacturing sector. Most of the time, the processing of biomaterials is characterized by a linear economy, as is the case with permanent implants, for example, which are removed from the human body after the bone fracture has been fixed.On the other hand, the circular economy is a system designed to eliminate waste and promote the continuous use of resources. It is founded on three principles: reduce, reuse, and recycle. Notably, bioabsorbable implant biomaterials fully embrace the concepts of circular economy and sustainability, as they dissolve within the body at a predetermined rate. Consequently, the devices produced will stem from more sustainable manufacturing practices, aligning with SDGs 9 (Industry, Innovation, and Infrastructure) and 12 (Sustainable Consumption and Production), while focusing on SDG 3 (Health and Well-being). Our collaboration proposal aims to produce and compare biodegradable metallic cages made from Fe-Zn-based alloys using 3D printing techniques: Extrusion-based 3D Printing and SLM (Selective Laser Melting). (AU)