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Table 1. Comparison of construction strategies and applications across multiple musculoskeletal system organoids
Construction Types of musculoskeletal system organoids
and Muscle organoid Bone organoid Tendon organoid Cartilage organoid Rotator cuff organoid
applications
Cell sources iPSCs; MSCs; TDSCs; BMSCs; BMSCs;
hPSCs; iPSCs; BMSCs; ADSCs; TDSCs;
human muscle-derived ESCs; human dermal iPSCs; ADSCs;
fibroblasts; PDCs fibroblasts PDCs hAMSCs
Matrix Matrigel; Matrigel; Matrigel; Matrigel; Matrigel;
materials hydrogel; natural hydrogel; dECM; hydrogel; hydrogel;
Matrigel with fibrin synthetic hydrogel; GelMA decellularized cartilage dECM;
collagen nanofiber
Construction CTM; Physical stimulus; 3D bioprinting; Microfluidics; Microfluidics;
techniques 3D bioprinting microfluidics; microfluidics 3D bioprinting 3D bioprinting;
3D bioprinting bioreactor
Applications Disease modeling; Bone modeling; Drug development; Cartilage repair; Rotator cuff simulation
drug screening; regeneration simulation; studies of research on pathological and repair
therapy test repair acceleration tenogenesis mechanism
Abbreviations: ADSCs: Adipose-derived stem cells; BMSCs: Bone marrow mesenchymal stem cells; CTM: Cascade tube microfluidics;
dECM: Decellularized extracellular matrix; ESCs: Embryonic stem cells; GelMA: Gelatin methacrylate; hAMSCs: Human amniotic membrane
mesenchymal stem cells; hPSC: Human pluripotent stem cells; iPSCs: Induced pluripotent stem cells; MSCs: Mesenchymal stem cells;
PDCs: Periosteum-derived cells; TDSCs: Tendon-derived stem cells; 3D: Three-dimensional.
cultivation methodologies share fundamental principles complexes that sterically block myosin cross-bridge binding
with traditional 2D cell culture yet exhibit critical sites. When electrical excitation is transmitted to the
distinctions in their capacity to recapitulate tissue-level myocyte through the transverse tubule system, the muscle
functional complexity. The fabrication of organoids completes its contractile movement through the excitation-
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relies on suitable cell types and sources, matrix materials, contraction coupling. As an important component of
biotechnology, and organoid construction strategies. 16,28 the locomotor system, skeletal muscle—along with bone,
Since the rotator cuff is a complex structure composed of connective tissue, and nerves—executes both fine motor
multiple tissues with structural and functional complexity, tasks and large movements such as grasping and walking,
rotator cuff organoid cultivation requires the integration of thus permitting the organism to accomplish daily life
multiple organoids, including skeletal muscle organoids, activities. In addition, skeletal muscle converts chemical
tendon organoids, bone organoids, and cartilage organoids. energy into mechanical energy through contraction and at
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In addition, a rigorous culture protocol is needed to ensure the same time, releases heat, acting as a thermoregulator.
the successful construction of the organoids, so that the Moreover, skeletal muscle modulates the systemic glucose
organoids can faithfully recapitulate the natural biological homeostasis through the synthesis and breakdown of
characteristics of rotator cuff tissues. glycogen. 25
2.1. Skeletal muscle organoids 2.1.2. Construction of skeletal muscle organoids

2.1.1. Physiological structure of skeletal muscle Common cell sources for skeletal muscle organoids
include induced pluripotent stem cells (iPSCs), human
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Skeletal muscle accounts for approximately 40% of the total pluripotent stem cells (hPSCs), and human muscle-
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body weight and is composed mainly of water, proteins, derived fibroblasts, with hPSCs being predominantly
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and other substances. Skeletal muscle is composed of employed in current protocols. These cells can give rise to
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myofibers; each myofiber is externally wrapped with cell lines such as myogenic progenitor cells and satellite
an endomysium. Many myofibers are wrapped by the cells through predefined cultivation strategies, which
perimysium to form muscle bundles, and multiple muscle ultimately coalesce into skeletal muscle organoids. In
bundles are further encapsulated by the epimysium to addition to the cell sources, optimized bioengineering
form muscles, which ultimately connect to the skeleton methodologies are equally crucial for the quality of skeletal
through tendons. Each myofiber consists of thousands of muscle organoids. In order to construct more responsive
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myofibrils, which in turn are composed of serially repeating organoids, researchers have explored the hanging drop
sarcomeres-the fundamental contractile units formed method, dynamic cell culture in spinner flasks, and culture
by myofilaments. The sarcomere is primarily composed in low attachment wells, rotating-wall vessels, and other
of thick myofilaments (myosin) and thin myofilaments techniques in the construction of skeletal organoids. Shin
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(actin). The actin is regulated by tropomyosin and troponin et al. implemented a stepwise, pre-patterned protocol to
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Volume 1 Issue 3 (2025) 3 doi: 10.36922/OR025320025