Preparation of CaSiO3 porous scaffold via DLP 3D printing and its surface modification through in situ growth of HAp

Calcium silicate (CaSiO 3 , CS) bioceramic has received widespread attention in the field of bone repair due to its excellent bone conductivity, osteoinductivtiy, and degradability. In this study, the porous CS scaffold was firstly prepared by digital light processing (DLP) 3D printing. The effects of solid loading, pore size, and sintering temperature on the compressive strength, porosity and shrinkage of the CS scaffold were thoroughly investigated. When the solid loading is 35 vol.%, the pore size is 500 µm, and the sintering temperature is 1200°C, the prepared CS scaffold has high porosity (48.96 %) and high compressive strength (32.13 MPa). To solve the problems caused by the rapid degradation of CS, surface modification of the prepared CS scaffold was further conducted through in situ growth of hydroxyapatite (HAp) on its surface. A large amount of HAp nanorods homogeneously grow on the surface of the CS porous scaffold when the concentration of KH 2 PO 4 in hydrothermal solution is 0.01 mol/L. Moreover, the phase composition and morphology of HAp grown on the surface of the CS scaffold can be controlled through controlling the concentration of KH 2 PO 4 .