The development of biomimetic and mechanically functional constructs remains a major challenge in skeletal muscle tissue engineering. In this study, we present a multi-component 3D bioprinted platform integrating a polycaprolactone (PCL) support for mechanical stimulation, a sacrificial gelatin (GE) matrix for controlled bioink deposition, and collagen-based bioinks laden with Rattus norvegicus L6 skeletal muscle cells. The influence of PCL architecture, GE concentration (0.75, 1.5 and 3 wt%), and bioink composition—collagen (C), collagen–Matrigel (CM), and extracellular matrix-based (ECM)—was systematically evaluated. Rheological characterization demonstrated that all bioinks exhibited shear-thinning behavior and suitable viscoelastic properties for extrusion-based bioprinting, with sufficient mechanical stability to withstand dynamic bioreactor conditions. Microstructural analysis revealed highly interconnected porous networks, particularly in ECM-based scaffolds. While no statistically significant differences were observed, the ECM-based bioinks showed the highest cell viability and improved structural organization. Overall, this work demonstrates a versatile bioprinting strategy that combines mechanical support and biomimetic environments, highlighting the potential of ECM-based bioinks for the fabrication of functional skeletal muscle constructs.

Injection molding is a plastic material processing technique used in the polymer industry. Because it is a complex process that requires injection cycles to achieve the desired aesthetic quality in the molded parts, it is essential to evaluate and configure all process parameters to predict and reduce defects, thereby decreasing the processing time and energy consumption. This study presents the results of tests performed on molded HDPE parts, including modeling and simulation using ANSYS^® (2025 R1), a design of experiments (DOE), and 3D scanning of the molded parts. The study compares the behavior of defects (warpages and sink-marks) in molded parts using 3D scanning with the results obtained from coupled thermal-structural field finite element simulations. These simulations were performed using software to assess the residual thermal stress of the ejection phase. The results visually display information that helps designers and engineers in the polymer processing sector evaluate molding-process failures using different software.