Fabrication of customized open-cell titanium foams by direct foaming for biomedical applications

Carolina Oliver-Urrutia, Mariano Casas-Luna, Zuzana Sumbalova Koledova, Karel Slámečka, Tomas Zikmund, Jozef Kaiser, Ladislav Čelko, Edgar B. Montufar, Fabrication of customized open-cell titanium foams by direct foaming for biomedical applications, Journal of Materials Research and Technology, Volume 33, 2024, Pages 1704-1714, ISSN 2238-7854, https://doi.org/10.1016/j.jmrt.2024.09.136.

Abstract

Titanium (Ti) foams offer a promising alternative for bone reconstruction and repair due to their high porosity and lower stiffness compared to solid metals, which improves in vivo osseointegration by reducing the stress shielding effect and allowing bone ingrowth. In this work, customized Ti foams were successfully fabricated for the first time at room temperature using a direct foaming method. Ti powder suspension with a water-soluble surfactant and environmentally friendly thickener was foamed by mechanical stirring. Then, 3D-printed moulds were utilized to achieve near-net shape foams, which were subsequently consolidated by sintering, thus avoiding the need for complex processing of molten Ti. The resulting Ti foams exhibited a cancellous-like open-cell structure, high porosity (> 80%), and a five times higher effective surface area than a 3D Ti mesh with a primitive cubic-based cell fabricated by additive manufacturing. In addition, the Ti foams exhibited similar mechanical properties to cancellous bone and facilitated the adhesion, proliferation, and maturation of human osteoblasts in vitro.

Keywords: Titanium; Metallic foam; Scaffold; Direct foaming; Robocasting; Osteoblast

   https://doi.org/10.1016/j.jmrt.2024.09.136