Ferrofluid-Based Bioink for 3D Printed Skeletal Muscle Tissues with Enhanced Force and Magnetic Response

Abstract

3D printing has emerged as a transformative technology in several manufacturing processes, being of particular interest in biomedical research for allowing the creation of 3D structures that mimic native tissues. The process of tissue 3D printing entails the construction of functional, 3D tissue structures. In this article, the integration of ferrofluid consisting of iron oxide nanoparticles into muscle cell-laden bioink is presented to obtain a 3D printed magnetically responsive muscle tissue, i.e., the ferromuscle. Using extrusion-based methods, the seamless integration of biocompatible ferrofluids are achieved to cell-laden hydrogels. The resulting ferromuscle tissue exhibits improved tissue differentiation demonstrated by the increased force output upon electrical stimulation compared to muscle tissue prepared without ferrofluid. Moreover, the magnetic component originating from the iron oxide nanoparticles allows magnetic guidance, as well as good cytocompatibility and biodegradability in cell culture. These findings offer a new versatile fabrication approach to integrate magnetic components into living constructs, with potential applications as bioactuators and for future integration in smart, functional muscle implants.