Synergistic Effects of Ceramic Fillers and NaOH Treatment on Bioactivity of 3D-Printed Poly(ε-caprolactone) Scaffolds...

Porous scaffolds composed of poly-(ε-caprolactone) (PCL) and ceramic fillershydroxyapatite (HAp) and β-tricalcium phosphate (β-TCP)were fabricated via extrusion-based additive manufacturing for bone tissue engineering applications. The scaffolds exhibited interconnected pores (∼400 μm) in a 0°-90° deposition pattern and were subjected to alkaline surface treatment with 1 M NaOH to increase surface roughness and promote partial exposure of embedded ceramic particles. Characterization included rheological analysis to assess processability, thermal evaluation via thermogravimetric analysis and differential scanning calorimetry, and surface morphology using scanning electron microscopy, energy-dispersive spectroscopy, and atomic force microscopy. Filler particle size was characterized, confirming submicron dimensions favorable for bioactive interaction; however, distribution within the polymer matrix was not directly evaluated. Mechanical testing under uniaxial compression revealed that ceramic addition increased stiffness and compressive strength. Protein adsorption assays indicated a significant increase in surface bioactivity following NaOH treatment. In vitro assays with MC3T3-E1 preosteoblastic cells confirmed good cytocompatibility, cell adhesion, and proliferation. Collectively, these findings suggest that the combination of ceramic incorporation and surface modification enhances both mechanical and biological performance, supporting the potential application of PCL-based scaffolds in bone regeneration strategies.