Cerium dioxide nanoparticles reinforced 3D-printed BCP bioceramic scaffolds toward enhanced mechanical, antioxidant, and osteogenic activities

The repair of bone defects exceeding the natural regenerative capacity of bone remains a significant clinical challenge. Although various strategies have been explored, 3D-printed bioceramic scaffolds have emerged as a promising therapeutic solution. However, conventional bioceramics suitable for 3D printing often exhibit insufficient mechanical strength, limited antioxidant activity, and insufficient osteogenic activity. To overcome these limitations, three-dimensional (3D)-printed scaffolds were fabricated by incorporating cerium dioxide nanoparticles (CeO 2 NPs) into biphasic calcium phosphate (BCP) bioceramics containing 70 wt% hydroxyapatite (HA) and 30 wt% β-tricalcium phosphate (β-TCP). This composite approach aimed to enhance both antioxidant activity and osteogenic differentiation. The physicochemical properties, antioxidant capacity, in vitro cellular responses, and osteogenic potential of the scaffolds were systematically assessed. Results demonstrated that scaffolds containing 10 wt% CeO 2 NPs showed significantly improved mechanical and biological performance, particularly in antioxidant activity, compared to pure BCP scaffolds. Furthermore, a slight increase in microenvironmental pH induced by the BCP matrix may further enhance the antioxidant effects of CeO 2 NPs and promote osteogenesis. This study presents a BCP-CeO 2 composite scaffold with dual functions of antioxidant activity and osteogenic induction. It highlights that integrating CeO 2 NPs into BCP bioceramics via 3D printing technology holds promise for developing multifunctional scaffolds suitable for advanced bone tissue engineering applications.