3D printing of Haversian bone-mimicking scaffolds for multicellular delivery in bone regeneration.

The integration of structure and function for tissue engineering scaffolds is of great importance in mimicking native bone tissue. However, the complexity of hierarchical structures, the requirement for mechanical properties, and the diversity of bone resident cells are the major challenges in constructing biomimetic bone tissue engineering scaffolds. Herein, a Haversian bone- mimicking scaffold with integrated hierarchical Haversian bone structure was successfully prepared via digital laser processing (DLP)-based 3D printing. The compressive strength and porosity of scaffolds could be well controlled by altering the parameters of the Haversian bone-mimicking structure. The Haversian bone-mimicking scaffolds showed great potential for multicellular delivery by inducing osteogenic, angiogenic, and neurogenic differentiation in vitro and accelerated the ingrowth of blood vessels and new bone formation in vivo. The work offers a new strategy for designing structured and functionalized biomaterials through mimicking native complex bone tissue for tissue regeneration.