Natural loofah sponge inspired 3D printed bionic scaffolds promote personalized bone defect regeneration

Critical-sized bone defects pose serious health concerns for patients. Clinically, the use of functionalized bone implants has emerged as an effective solution. However, the rapid advancement in drug and biomaterials has led to an increasing design cost, triggering discussions in the field about how to efficiently create customized functional bone implants. Inspired by the unique structure of natural loofah sponges that effectively deliver nutrients to seeds, we designed a functionalized bone implant emulating this structure. Drug-release gradients were achieved through the application of different concentrations of hydrogels within the composite scaffold. This approach allowed active substances to be released outwardly during the early stage of bone repair, sustaining a local drug micro-environment within the implant scaffold that promotes angiogenesis and osteogenic differentiation in damaged areas. In vivo experiments showed that our loofah sponge bionic scaffold outperformed traditional hydroxyapatite scaffolds by promoting both bone and vascular regeneration. We expect the design of loofah sponge bionic scaffold could potentially deliver an effective strategy in the development of functionalized bone implants.