Formation of contractile 3D bovine muscle tissue for construction of millimetre-thick cultured steak

Abstract

Owing to the increase in the global demand of meat, cultured meat technology is being developed to circumvent a shortage of meat in the future. However, methods for construction of millimetre-thick bovine muscle tissues with highly aligned myotubes have not yet been established. Here, we propose a culture method for constructing 3D-cultured bovine muscle tissue containing myotubes aligned along its long-axial direction, which contracted in response to electrical stimulation. First, we optimised the composition of biomaterials used in the construction and the electrical stimulation applied to the tissue during culture. Subsequently, we fabricated millimetre-thick bovine muscle tissues containing highly aligned myotubes by accumulating bovine myoblast-laden hydrogel modules. The microbial content of the bovine muscle tissue cultured for 14 days was below the detection limit, indicating that the muscle tissues were sterile, unlike commercial meat. Therefore, the proposed construction method for bovine muscle tissues will be useful for the production of clean cultured steak meat simulating real meat.

Perfusable System Using Porous Collagen Gel Scaffold Actively Provides Fresh Culture Media to a Cultured 3D Tissue

“…It is expected that perfusion may affect the viability of tissues if other cell types with higher metabolism or cell tissues with more layered cell sheets are employed in this system. The fabrication of 3D cell tissue is a very common goal in tissue engineering, which is a basic technology for regenerative medicine, cell-based food, and drug screening assay models [1][2][3]. Furthermore, although the scaffold was made of native collagen gel, another type of biocompatible porous gel could be utilized.…”

“…In recent years, there has been a rapid increase in the number of bioengineering studies using cultured cell tissues, such as regenerative medicine, drug screening systems in vitro, and the fabrication of cell-based food [1][2][3][4]. As a common and important technology in such fields, culture technologies required to realize physiological conditions and to develop valuable cell tissues have been investigated, and the fabrication of three-dimensional (3D) cell tissues has attracted considerable attention [5][6][7].…”

Manufacturing of animal products by the assembly of microfabricated tissues

“…After the fabrication of muscle tissue, further maturation from 10 to 21 days were conducted to achieve functional and morphological characteristics of the muscle such as contractile force and striped patterns within the tissue (e.g. sarcomere) [100][101][102][103]. Since these presented examples are based on proof-of-concept, biomaterials such as fibrin, Matrigel, collagens, and serums are used to fabricate the in-vitro muscle tissue.…”

“…To mimic the densely packed structure of muscle which consists of fat and blood vessel, highly aligned structure of muscle in large scale is required. To overcome the current challenges, microtissue assembly methods are proposed to fabricate muscle tissue in large scale such as spinning [ 4 ], cell layering [ 100 , 101 ], 3D bioprinting [ 102 , 103 ] ( Figure 2 (D-i,ii)). Using spinning method, mass production of the fibrous gelatin was achieved that encourages adhesion of muscle cells to proliferate and align along the gelatin fiber [ 4 ].…”

“…Using spinning method, mass production of the fibrous gelatin was achieved that encourages adhesion of muscle cells to proliferate and align along the gelatin fiber [ 4 ]. Utilizing cell layering method, cell-laden hydrogel sheet with multilayered structure was fabricated fulfilling the functional characteristics of the muscle with contractile force [ 100 , 101 ] and similar breaking force (5.08 N) to that of the beef tenderloin (6.11 N) [ 101 ]. Through 3D bioprinting, muscle tissues with highly organized structure to guide cell alignments [ 105 ].…”