Fabrication of PCL Blended Highly Aligned Nanofiber Yarn from Dual-Nozzle Electrospinning System and Evaluation of the Influence on Introducing Collagen and Tropoelastin

Conventional electrospinning is a widely used method for creating nanofibrous structures that show promise in skin wound healing. However, the membranes generated through conventional electrospinning techniques lack reproducibility, scalability, and sufficient mechanical strength, ultimately limiting their potential for clinical applications. In this study, we present a new approach for fabricating biomimetic yarn using a dual-nozzle electrospinning system that collects nanofiber yarn from a rotating funnel. Polycaprolactone (PCL) was combined with collagen-I and tropoelastin in the electrospinning solution to provide relevant biochemical cues necessary for human dermal fibroblast (HDF) cells while maintaining structural integrity. The novel yarns exhibited a hierarchical structure akin to collagen fibers forming the dermal layer of the skin. Furthermore, these yarns demonstrated superior mechanical strength compared to conventional electrospun nanofiber webs. Live/dead fluorescence staining and alamarBlue assays revealed that yarns incorporating both collagen-I and tropoelastin supported significantly higher HDF attachment (18.55% at 24 h) and sustained proliferation, increasing 2.93-fold from Day 1 to Day 7, compared to the PCL-only control yarns (9.34% at 24 h; 2.68-fold increase). Scanning electron microscopy (SEM) observations confirmed that cells on protein-containing yarns formed a continuous, smooth cell layer with elongated, spindle-shaped morphology which was aligned along the yarn axis. This highlights the critical role of yarn architecture in guiding cell orientation and organization. The combined biochemical cues from collagen-I and tropoelastin, together with the aligned, twisted yarn architecture, produced scaffolds that not only enhanced cell adhesion and proliferation but also promoted native-like cell alignment and confluence. This synergistic integration of biochemical signaling and structural guidance underscores the potential of these electrospun yarns as advanced dermal scaffolds, offering both mechanical robustness and functional bioactivity for future wound healing and regenerative medicine applications.