Fabrication of 8-TCP/ Akermanite composite scaffold via DLP and in-situ modification of micro-nano surface morphology for bone repair

Although 8-TCP bioceramics possess favorable biocompatibility and bioactivity, their inherent brittleness restricts further applications. In this study, we aimed to enhance the mechanical performance and biocompatibility of 8-TCP by incorporating 15% Akermanite (AK) into the structure. The fabrication process involved the use of digital light processing (DLP) technology to fabricate ceramic green bodies, followed by high-temperature debinding and sintering to obtain the ceramic scaffold. Subsequently, we employed an in-situ growth technique to create micro/nano surface topography on the scaffolds, facilitating synergistic regulation of cell behavior in conjunction with the controlled release of bioactive agents. Scanning electron microscopy (SEM) revealed that the addition of AK enlarged the grain size and reduced the number of micropores in the composite scaffold. Furthermore, after the in-situ growth treatment, a significant increase in micro/nano surface features was observed. Mechanical testing demonstrated that the incorporation of AK effectively improved the mechanical properties of the composite scaffold, resulting in an increase in strength of approximately 20%. Cell experiments indicated that AK supplementation further enhanced the material's cell compatibility, and the presence of micro/nano structures effectively promoted cell adhesion, proliferation, and expression of osteogenic genes. Consequently, we propose a strategy for fabricating porous bioceramics that stimulate bone growth, exhibit high strength, and ameliorate the degradation microenvironment. This approach opens up promising avenues for future applications in bone tissue engineering.