Decoupling Bioactivity and Processability: RGD Click-Functionalized Coatings for a 3D-Printed PCL Scaffold

This study presents a modular surface functionalization method for 3D-printed poly(ε-caprolactone) (PCL) scaffolds using a clickable PCL derivative functionalized with maleimide groups (PCL-AE-L). The coating enables thiol–maleimide Michael addition with bioactive RGD peptides, improving cell adhesion and mineralization without altering bulk printability or mechanics. The PCL@RGD scaffolds exhibited enhanced wettability (contact angle reduced to 34°), increased surface roughness (Ra ≈ 46 µm), and supported greater SAOS-2 osteoblast adhesion and calcium deposition compared to unmodified scaffolds. This method decouples bioactivity enhancement from printing parameters, offering a tunable, post-processing strategy for bone tissue engineering.