Copper-modified mesoporous kaolin–loaded bioinks promote osteogenesis, angiogenesis, and antibacterial activity in 3D-bioprinted hydrogels

Despite advancements in vat-based three-dimensional (3D) bioprinting, there remains a critical shortage of suitable bioinks that combine osteogenic, angiogenic, and antimicrobial properties for bone tissue engineering. In this study, we developed a multi-biofunctional composite bioink by integrating copper-modified mesoporous kaolin (MKCu) into a pectin methacrylate (PMA) and silk fibroin methacrylate (SFMA) matrix. MKCu was synthesized via acid leaching and Cu 2+ ion exchange from native kaolin, followed by comprehensive physicochemical characterization. Nanocomposite hydrogels with varying MKCu content were then fabricated using high-resolution digital light processing (DLP) 3D printing. Our results demonstrate that MKCu incorporation enhances antimicrobial activity against both Gram-positive and Gram-negative bacteria. Furthermore, in vitro assays revealed that the MKCu-loaded scaffolds significantly enhanced the viability ( p < 0.001), proliferation, and osteogenesis ( p < 0.01) of pre-osteoblasts up to Day 21, while simultaneously stimulating the migration and network-forming ability of endothelial cells. These findings indicate that MKCu/SFMA-PMA composite bioinks provide a multifunctional platform for the fabrication of advanced bone regenerative constructs.