Extrusion-based 3D Printing of PEG400-Plasticized HA/PCL Composite Scaffolds: A Study on Flexible Adaptation for Eyelid Defect Repair

Purpose This study developed extrusion-based 3D-printed PEG400-plasticized HA/PCL composite scaffolds for posterior lamellar eyelid reconstruction, optimizing material ratios to match native tarsal tissue properties. Methods Two scaffolds (70% vs 84% HA) were fabricated via pneumatic extrusion. Microstructure (SEM), porosity (Micro-CT), wettability (contact angle), and mechanical properties (tensile testing) were characterized. Statistical analysis used GraphPad Prism 8. Results The 84% HA scaffold achieved an elastic modulus of ​2.66 MPa, closely aligning with native tarsal tissue (1.73 ± 0.61 MPa). Hierarchical pores (macropores: ~570.7 µm; micropores: ~20.81 µm) and high porosity (91.66%​) were observed. Both scaffolds showed hydrophilicity (contact angles: ​80.63°​ for 70% HA; ​77.97°​ for 84% HA). Though the 84% HA group had lower tensile strength, its biomechanical compatibility surpassed the 70% HA scaffold. Conclusion The 84% HA/PCL scaffold exhibits optimal mechanical adaptation, porous architecture, and hydrophilicity for eyelid tarsal reconstruction. Its slow degradation profile supports clinical potential, pending in vitro cytocompatibility and in vivo validation.