Application of piezoelectric cells printing on three-dimensional porous bioceramic scaffold for bone regeneration

Abstract

In recent years, the additive manufacture was popularly used in tissue engineering, as the various technologies for this field of research can be used. The most common method is extrusion, which is commonly used in many bioprinting applications, such as skin. In this study, we combined the two printing techniques; first, we use the extrusion technology to form the ceramic scaffold. Then, the stem cells were printed directly on the surface of the ceramic scaffold through a piezoelectric nozzle. We also evaluated the effects of polydopamine (PDA)-coated ceramic scaffolds for cell attachment after printing on the surface of the scaffold. In addition, we used fluorescein isothiocyanate to simulate the cell adhered on the scaffold surface after ejected by a piezoelectric nozzle. Finally, the attachment, growth, and differentiation behaviors of stem cell after printing on calcium silicate/polycaprolactone (CS/PCL) and PDACS/PCL surfaces were also evaluated. The PDACS/PCL scaffold is more hydrophilic than the original CS/PCL scaffold that provided for better cellular adhesion and proliferation. Moreover, the cell printing technology using the piezoelectric nozzle, the different cells can be accurately printed on the surface of the scaffold that provided and analyzed more information of the interaction between different cells on the material. We believe that this method may serve as a useful and effective approach for the regeneration of defective complex hard tissues in deep bone structures.

Keywords: Bone tissue engineering; Calcium silicate; Drop-on-demand; Piezoelectric printing; Polycaprolactone; Polydopamine.

Figure 1

Schematic diagram of the bioprinting process. First, a framework was fabricated with calcium silicate/polycaprolactone (CS/PCL) and polydopamine CS/PCL composite to support scaffold stability. Second, the cells (or fluorescein isothiocyanate) were printed on the scaffold surface by the piezoelectric needle.

Figure 2

The water contact angle of calcium silicate/polycaprolactone (CS/PCL) and polydopamine CS/PCL scaffolds.

Figure 3

(A) The fluorescein isothiocyanate solution adsorbed on the calcium silicate/polycaprolactone (CS/PCL) or polydopamine CS/PCL surface after printing for 0 and 30 min. Scale bar: 400 µm. (B) The Col I and fibronectin adsorbed on scaffolds surface for 30 min. “*” indicates a significant difference (P<0.05) compared to CS/PCL.

Figure 4

(A) The cell adhered and (B) proliferated on calcium silicate/polycaprolactone (CS/PCL) or polydopamine CS/PCL scaffold after printing for different time-points. “*” indicates a significant difference (P<0.05) from CS/PCL. (C) The immunofluorescence of Wharton’s jelly mesenchymal stem cells cultured on CS/PCL or PDACS/PCL scaffolds for 3 days. Scale bar: 100 µm.

Figure 5

The alkaline phosphatase expression in the Wharton’s jelly mesenchymal stem cells was cultured on calcium silicate/polycaprolactone (CS/PCL) or polydopamine CS/PCL scaffolds after printing 3 and 7 days. “*” indicates a significant difference (P<0.05) compared to CS/PCL.

Figure 6

(A) The immunofluorescence image of RFP-cell and GFP-cell after printing on polydopamine calcium silicate/polycaprolactone scaffold surface. Scale bar: 400 µm. (B) The amounts of RFP-human umbilical vein endothelial cells and GFP-Wharton’s jelly mesenchymal stem cells cultured on scaffold for different time-point. “*” indicates a significant difference (P<0.05) compared to day-1. “#” indicates a significant difference (P<0.05) compared to day-3.