Tensile-Spun Gelatin–Chitosan Composite Scaffolds with Tunable Structure–Property Relationships

Engineering fibrous scaffolds with anisotropic architecture, tunable mechanics, and hydrated stability is essential for constructing physiologically relevant muscle tissue models. Here, we introduce gelatin–chitosan (GC) composite scaffolds fabricated via a tensile spinning process, enabling the formation of continuously aligned fibers without toxic solvents. Systematic modulation of chitosan content governed precursor viscoelasticity, which translated into controlled fiber alignment, pore characteristics (20–26%), hydrated-state resilience, and stiffness spanning 3–87 kPa. Spectroscopic and surface-potential analyses revealed compositional regulation of intermolecular interactions and surface-accessible functional groups, establishing a direct link between the GC formulation and interfacial chemical properties. Intermediate formulations exhibited an optimal convergence of structural and interfacial attributes─moderate stiffness, sustained diffusivity, and accessible oxygen- and nitrogen-bearing functionalities─conditions that supported high myoblast adhesion, viability, and directional cytoskeletal alignment. Notably, GC 4.0 scaffolds promoted anisotropic myotube formation along the fiber axis, underscoring the requirement for co-optimized fiber alignment, hydrated mechanical integrity, and surface chemistry in functional myogenesis. By integrating compositional control with architectural and interfacial outcomes, this work establishes a unified formulation–structure–function relationship for gelatin–chitosan scaffolds. Rather than introducing a new material class, the findings reveal how incremental variation in the chitosan content within a toxic solvent-free spinning platform yields structurally aligned, compositionally responsive fibrous scaffolds capable of directing muscle cell organization, offering a refined design framework for next-generation muscle tissue engineering.