3D in vitro models of skeletal muscle: myopshere, myobundle and bioprinted muscle construct

Abstract

Typical two-dimensional (2D) culture models of skeletal muscle-derived cells cannot fully recapitulate the organization and function of living muscle tissues, restricting their usefulness in in-depth physiological studies. The development of functional 3D culture models offers a major opportunity to mimic the living tissues and to model muscle diseases. In this respect, this new type of in vitro model significantly increases our understanding of the involvement of the different cell types present in the formation of skeletal muscle and their interactions, as well as the modalities of response of a pathological muscle to new therapies. This second point could lead to the identification of effective treatments. Here, we report the significant progresses that have been made the last years to engineer muscle tissue-like structures, providing useful tools to investigate the behavior of resident cells. Specifically, we interest in the development of myopshere- and myobundle-based systems as well as the bioprinting constructs. The electrical/mechanical stimulation protocols and the co-culture systems developed to improve tissue maturation process and functionalities are presented. The formation of these biomimetic engineered muscle tissues represents a new platform to study skeletal muscle function and spatial organization in large number of physiological and pathological contexts.

Optimizing the Surface Structural and Morphological Properties of Silk Thin Films via Ultra-Short Laser Texturing for Creation of Muscle Cell Matrix Model

“…profilometer analysis, are presented in Table 1. As already mentioned, the specific patterning conditions were chosen in relation to the optimal dimensions and morphology of the patterns created by the laser in respect to the myoblast cells' suitable seeding conditions [65]. The obtained results are in accordance with the morphological findings acquired from the SEM analysis.…”

“…To promote the natural regeneration process, the distance between the microchannels was also precisely controlled to be optimized with respect to cellular dimensions and orientation inside the channels. According to the literature, widths of grooves and ridges promoting C2C12 alignment and differentiation vary between 20 µm and 100 µm [13,61,64,65]. All analyses of the fs structured samples that followed were averaged on ten separate measurements and performed in respect to the control, a laser non-treated SF scaffold.…”

“…A representative selection of 3D real-color images, obtained under variation of F and V in respect to a non-treated surface, is given in Figure 3; the corresponding Ra and Sa roughness parameters of all the groups of samples, measured during the optical profilometer analysis, are presented in Table 1. As already mentioned, the specific patterning conditions were chosen in relation to the optimal dimensions and morphology of the patterns created by the laser in respect to the myoblast cells' suitable seeding conditions [65].…”

“…There is no evidence of mechanical distortion of the biopolymer material. Based on a literature survey, the optimal dimensions for muscle cells vary between 20 µm and 100 µm, as during skeletal muscle formation or regeneration, myoblasts fuse into multi-nucleated tubes to form myofibers, the muscle's basic "building blocks", whose diameter ranges in this diapason, depending on the muscle location and function [13,64,65]. By tuning the applied laser parameters (F and V), the SF scaffolds morphology could maximally mimic the ECM of the muscle tissue and be "personally" designed in respect to the specific needs of the seeded cell line.…”

Use of animal models to understand titin physiology and pathology

“…3D cultures mimic the structure and the functionality of human muscle tissues. Although currently the physiological properties of the 3D cultures are not yet comparable with those found in vivo in tissues, they may soon become a very useful tool for muscle disease modelling 74 . Since each of these approaches presents issues that can compromise its effectiveness, their synergistic use could be optimal to understand how a specific titin mutation leads to the development of a given clinical phenotype.…”