Biomimetic 3D printing of photocrosslinkable biodegradable elastomers-modified hybrid scaffolds as instructive platforms for bone tissue regeneration

3D printing is regarded as an ideal method for large-scale bone defect repair. A rapid curing rate and strong mechanical properties throughout the product's shelf life are key development goals in 3D-printed bone repair biomaterials. To achieve this goal, we developed a 3D-printable organic/inorganic composite ink featuring rapid curing and highly customizable properties. After 3D printing, the nanocomposite ink of poly (glyceryl sebacate)-2-chlorocinnamoyl chloride/β-tricalcium phosphate (PGS-CC/β-TCP) undergoes short-term light crosslinking to form a biomimetic network of inorganic-organic composite materials. The resulting bone repair scaffold possesses excellent mechanical properties, significantly promotes cell adhesion and proliferation, and demonstrates good in vitro osteogenic activity, angiogenic performance, and mineralization capability. Moreover, the PGS-CC/β-TCP 3D-printed scaffold exhibits good degradation performance, retaining its mechanical properties even after four weeks of degradation. The PGS-CC(1:2)/β-TCP composite scaffold can effectively repair severe cranial bone defects in rats, showing optimal in vivo osteogenic and degradation performance at 6 and 12 weeks. With these advantages, this innovative 3D-printed biomaterial has great clinical application prospects for large segment bone repair and provides new opportunities for other complex reconstructions.