Biomaterial-Based Patterning-Driven Pseudo-3D Topological Alignments Regulate Mechanotransduction and Maturation in Muscle Tissue Engineering

Biomaterials used in muscle tissue engineering must account for the sensitivity of muscle tissue to mechanical stimuli, making it crucial to understand mechanotransduction pathways and their impact on muscle cell fate. Yes-associated protein 1 (YAP) translocates to the nucleus in response to mechanical cues, functioning as a pivotal regulator of phenotypic alterations in human smooth muscle cells (SMCs). However, the influence of biomaterial-driven topographical cues on YAP activity and the maturation processes of SMCs is not fully understood, leading to inconsistent findings across studies. This research investigates how different topographical patterns engineered into biomaterial substrates influence SMC mechanotransduction and maturation. Utilizing laser engraving techniques, we developed biomaterial scaffolds with line, cross, and curve patterns (300 µm width and 150 µm depth), replicating natural muscle tissue's structural characteristics, along with flat control regions. Results indicated that cross-patterned biomaterial substrates, coupled with cell-cell interactions, enhanced YAP-mediated mechanotransduction and promoted SMC maturation, particularly through calponin-related pathways. In contrast, at lower SMC densities, mechanotransduction associated with Lamin A was enhanced, though maturation was limited due to insufficient cell-cell communication. Inhibition assays revealed that YAP-mediated mechanotransduction, rather than focal adhesion signaling pathways, played a predominant role, particularly in calponin-linked maturation over α-SMA-linked contractile phenotype shifts, both in vitro and in vivo. These findings were consistent across dynamic environments, highlighting the role of topographical cues in guiding mechanotransduction and SMC maturation. The study underscores the importance of biomaterial-based patterning in scaffold design for muscle tissue engineering, offering insights into tailoring material properties to direct specific cellular responses.