Engineered bone scaffolds with Dielectrophoresis-based patterning using 3D printing.

Patterning of cells into a specific pattern is an important procedure in tissue engineering to facilitate tissue culture and ingrowth. In this paper, a new type of 3D-printed scaffold utilizing dielectrophoresis (DEP) for active cell seeding and patterning was proposed. This scaffold adopted a concentric-ring design that is similar to native bone tissues. The scaffold was fabricated with a commercial three-dimensional (3D) printer. Polylactic Acid (PLA) was selected as the material for the printer and the fabricated scaffold was coated with gold to enhance the conductivity for DEP manipulation. Simulation from COMSOL confirmed that non-uniform electric fields were successfully generated under a voltage input. The properties of the scaffold were first characterized through a series of experiments. Then, preosteoblast MC3T3-E1 cells were seeded onto the coated scaffold and multiple cellular rings were observed under the microscope. The biocompatibility of the material was also examined and mineralized bone nodules were detected using Alizarin Red S Staining after 28 days of culture. The proposed scaffold design can enable formation of multiple ring patterns via DEP and the properties of the scaffold are suitable for bone tissue culture. This new type of 3D-printed scaffold with cell seeding mechanism offers a new and rapid approach for fabricating engineered scaffolds that can arrange cells into different patterns for various tissue engineering applications.