Session Overview |
Friday, May 24 |
10:30 |
Characterization of biodegradable metals A perspective on the use of synchrotron radiation-based techniques
* Berit Zeller-Plumhoff, Helmholtz-Zentrum Hereon, Germany Biodegradable metals represent a critical opportunity in revolutionizing the implant market. To evaluate their desired functioning when tailoring their microstructure or similar, it is pivotal to utilize appropriate characterization techniques. While hydrogen evolution measurements and histology are certainly gold standards that will remain relevant throughout, correlative measurement techniques are becoming increasingly powerful and relevant. Synchrotron radiation (SR)-based imaging and characterization techniques for example present unique opportunities to study the peri-implant tissue morphology and structure in 3D. This talk will provide an overview of the current state of the art and a perspective for future directions in the characterization of biodegradable metals using SR-based techniques, as well as correlative methods. |
11:15 |
Biodegradable Metals for Transient Electronics
* Seung-Kyun Kang, Seoul National University, South Korea Biodegradable materials in implantable medical devices have the distinct advantage of not requiring removal after therapeutic use, thereby reducing the risks of infection or biofilm formation due to residual matter. This also minimizes the risks and discomfort associated with secondary surgeries needed for device removal. Recently, there has been active research in integrating flexible and stretchable ultrathin electronic devices with biotechnologies for diagnostic and therapeutic applications. An emerging concept in this field is "transient electronics," which are designed to perform diagnostic and therapeutic functions electronically within the body and then completely dissolve, similar to traditional biodegradable implants.[1-4] This study introduces the concept of biodegradable electronic devices through various application examples, including brain pressure sensors for diagnosing traumatic brain injury with latent periods[1] and wireless neurostimulators that accelerate regeneration for quicker neural recovery,[2] alongside drug delivery devices. We aim to highlight trends in research on biodegradable metals, extending beyond studies on biocompatibility and degradation rates to include electrical properties. Innovations in processing techniques for thin film formation and microstructure design for biodegradable metals will be discussed. This presentation will introduce studies on the use of amorphous alloys to improve the mechanical deformability of Mg metal-based systems and zinc alloying to enhance corrosion characteristics. |
11:45 |
Development of methodologies to improve tensile stress simulation and testing correlation of stents and other biomedical materials
* Marta Multigner, Universidad Rey Juan Carlos, Spain Daniel Valdés, Universidad Rey Juan Carlos, Spain Juan Manual García-Zapata, Universidad Rey Juan Carlos, Spain Irene Limón, Universidad Rey Juan Carlos, Spain Juan Manual García-Zapata, Universidad Rey Juan Carlos, Spain Juan Pablo Fernández-Hernán, Universidad Rey Juan Carlos, Spain Sandra Cifuentes, Universidad Rey Juan Carlos, Spain Marta Muñoz, Universidad Rey Juan Carlos, Spain Belén Torres, Universidad Rey Juan Carlos, Spain Joaquín Rams, Universidad Rey Juan Carlos, Spain Numerical testing of biomedical materials has gained significant interest to reduce the necessity of extensive experimental tests under a wide range of scenarios, facilitating more informed design decisions. However, the adequate feeding of mechanical properties is crucial for a precise simulation. It is important to ensure that simulation setups and results of mechanical characterization tests do not hide any important mechanism that could cause critical failure in in vivo experiments. For this reason, it is convenient that the simulation data are fed with realistic mechanical properties determined experimentally. This is particularly critical with complex manufacturing processes such as additive manufacturing (AM). AM of metals by the laser powder bed fusion (LPBF) has gained focus because it allows the manufacture of the personalized and intricate geometries that the biomedical industry demands. For instance, there is clear evidence that design of biomedical devices such as stents influences restenosis and clinical outcomes. There are a wide variety of stent designs available and AM has increasingly been considered for the development of biodegradable metallic cardiovascular stents. However, tensile, shear, and fracture properties of AM pieces depend on the direction considered, and all these parameters must be developed to feed the simulations. For orthopedic prostheses and stents, test specimens with specific geometries were defined to measure the mechanical properties along the principal orientations. For stents, one of the main concerns during characterization is the deformations and stress induced by the griping system of the testing equipment. To avoid this, the authors have come up with a solution in which pieces include stent, grips, and a transition zone that allows the strain transmission. This samples have been tested in tensile and compression, and in quasistatic or dynamic conditions. The results through simulation and tensile stress tests obtained in a conventional way and using the proposed specimens have been compared. |
12:00 |
Discussion on morning presentations
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