Three-dimensional printing of gyroid-structured composite bioceramic scaffolds with tuneable degradability

Highlights: • Fine gyriod-structure ceramic scaffolds are fabricated by Digital light processing. • Degradability of scaffolds can be tailored by 45S5 bioglass® content accurately. • The improved apatite-forming ability exhibit an excellent bioactivity of scaffolds. Customisation of bioactivity and degradability of porous bioceramic scaffolds is a formidable challenge in the field of regenerative medicine. In this study, we developed gyroid-structured ternary composite scaffolds (biphasic calcium phosphate (BCP) and 45S5 bioglass® (BG)) using digital light processing 3D printing technology based on material and structural design. Additionally, the mechanical strength, bioactivity, degradability, and biocompatibility of the composite ceramic scaffolds were evaluated. The results revealed that BG reacted with BCP to generate major active crystalline phases of CaSiO₃ and Na₃Ca₆(PO₄)₅. These active crystalline phases accelerated the exchange rate of Si⁴⁺, Ca²⁺, and PO₄³⁻ with HCO³⁻ in simulated body fluids and resulted in the rapid formation of carbonated hydroxyapatite (CHA), analogous to the formation of natural bone tissue. Interestingly, the precipitated CHA showed petal- and needle-like morphologies, which provided a large surface area to promote cell adhesion and proliferation. Furthermore, an increase in the BG content improved the degradability of ternary composite scaffolds after soaking in Tris-HCl solution. The tuneable degradability increased by three times at 30 wt% BG and sharply increased by 6.8 times at 40 wt% BG. This study provides a promising strategy to design scaffolds with improved bioactivity and tuneable degradability to assist a diverse population suffering from orthopedic conditions.