Speaker
Description
Introduction. Achieving physiologically relevant maturation of engineered skeletal muscle in vitro remains a major challenge in tissue engineering (1, 2). Traditional stimulation approaches often fail to recapitulate the spatiotemporal precision of native neuromuscular activation (3, 4). In this context, light-responsive molecular transducers represent a promising tool to drive muscle excitation with high spatial and temporal resolution (5, 6). Here, we explore the use of intramembrane azobenzene-based photoswitches for the functional enhancement of 3D skeletal muscle constructs and investigate how photostimulation influences biological changes associated with muscle maturation.
Methods. Engineered skeletal muscle bundles were fabricated using a rotary wet-spinning technique with murine myoblasts embedded in hydrogel-based core-shell fibers. After differentiation, tissues were treated with Ziapin2 (7), a photoresponsive small molecule that integrates into the plasma membrane. Constructs were exposed to photostimulation protocols (variable frequency and duration), and contractile dynamics were evaluated through high-speed video analysis. Structural organization was assessed via confocal microscopy and quantified using maturation indexes. Tissues displaying the most mature phenotype were subjected to molecular characterization.
Results. Preliminary observations suggest that photostimulated muscle constructs may exhibit improved contractile behavior when compared to non-stimulated controls, including more regular contraction patterns and increased responsiveness. Structurally, a trend toward enhanced sarcomere organization and alignment was observed in stimulated samples. Early molecular analyses are being conducted to explore how photostimulation might influence the expression of muscle-specific markers and features linked to fiber-type specification. These investigations aim to identify potential molecular signatures and structural correlates of functional maturation in response to light-based activation.
Discussion. Initial data support the hypothesis that light-driven, non-genetic stimulation could promote both structural and functional maturation of engineered skeletal muscle constructs. This strategy may offer key advantages over conventional stimulation methods, particularly in terms of precision and adaptability. While further validation is ongoing, early results point to biological changes associated with photostimulation, involving molecular pathways related to contractile function and fiber-type differentiation. These findings highlight the potential of photostimulation as a tunable and non-invasive tool for advancing in vitro muscle modeling, with promising implications for applications in regenerative medicine.
References
1- Williamson A. et al., 2024; Bioreactors: A Regenerative Approach to Skeletal Muscle Engineering for Repair and Replacement.
2- Jiang Y. et al., 2022; Bioengineering human skeletal muscle models: Recent advances, current challenges and future perspectives.
3- Hu W. et al., 2020; Optogenetics sheds new light on tissue engineering and regenerative medicine.
4- Mueller C. et al., 2021; Effects of External Stimulators on Engineered Skeletal Muscle Tissue Maturation.
5- Florindi C. et al., 2024; Role of stretch-activated channels in light-generated action potentials mediated by an intramembrane molecular photoswitch.
6- Venturino I. et al., 2023; Skeletal muscle cells opto-stimulation by intramembrane molecular transducers.
7- Vurro V. et al., 2023; Membrane Order Effect on the Photoresponse of an Organic Transducer Membranes.
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