Pneumatic extrusion-based three-dimensional (3D) printing can be used to fabricate custom-made scaffolds to restore irregular bone defects. During the 3D printing process, therapeutic agents can be added to the scaffolds. This study aimed to develop a polycaprolactone (PCL) scaffold loaded with Ag3PO4 to prevent infections and lidocaine for pain relief by one-step 3D printing. We hypothesized that the drug release could be controlled by varying the filament diameter of the 3D printed scaffolds. To this end, PCL slurry mixed with different amounts of silver phosphate and lidocaine was printed via differently sized nozzles. The obtained cylindric scaffolds displayed a porous interconnected microstructure with high fidelity. The Ag3PO4 and lidocaine were distributed homogeneously. The lidocaine release could be controlled by adjusting the filament diameter while the silver release is correlated with the Ag3PO4 loading amount. The released medium from silver-loaded scaffolds exhibited an obvious inhibition zone against Staphylococcus aureus and Escherichia coli upon loading with 1% Ag3PO4 for up to 6 days and with 3% Ag3PO4 for at least 7 days. Cytotoxicity of all scaffolds was screened by cell assay. In conclusion, the pneumatic extrusion-based 3D printing provides a practical technique to fabricate drug-loaded scaffolds. The Ag3PO4 and lidocaine loaded PCL scaffolds showed the potential for infection prevention and pain relief.
Keywords: 3D printing; antibacterial; lidocaine; polycaprolactone; silver.