Development of Functional Amine Coatings on <scp>3D</scp>‐Printed <scp>PCL</scp> Scaffolds via Nonthermal Atmospheric Pressure Plasma for Tissue Engineering Applications

ABSTRACT This study aims to enhance 3D‐printed poly‐ε‐caprolactone (PCL) scaffolds for bone tissue engineering. For this purpose, an amine‐rich coating was applied on the surface of the scaffold using nonthermal atmospheric plasma polymerization of allylamine. The applied potential (16, 18, and 20 kV) and flow rates (2, 4, and 6 lpm) were explored with respect to the surface properties of the plasma‐polymerized PCL scaffolds. A variety of characterization techniques were employed to examine the samples, including X‐ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), atomic force microscopy (AFM), and contact angle (CA) assessments. The findings from XPS indicated that elevated potentials enhanced the incorporation of amine functional groups. Images obtained via atomic force microscopy (AFM) and scanning electron microscopy (SEM) demonstrated a notable augmentation in surface roughness with increased discharge potentials. Contact angle measurements showed considerable improvement in hydrophilicity for the surface‐modified PCL scaffolds. Moreover, from in vitro investigation, it was found that the scaffolds modified with high retention of monomeric functionalities demonstrated significant cell‐compatible properties. Conclusively, this work establishes the fact that this new technique of plasma polymerization can improve the surface properties of PCL scaffolds, and by appropriate selection of operating parameters, amine coatings could be optimized to enhance the cytocompatibility of the PCL scaffolds.