Direct three-dimensional printing of a highly customized freestanding hyperelastic bioscaffold for complex craniomaxillofacial reconstruction

Abstract

Due to the anatomical and functional complexities, craniomaxillofacial defects are considered as one of the most intractable orthopedic challenges worldwide. Despite substantial attention given to the development of tissue-engineering biomaterials, poor customization, function, and clinical application of current artificially fabricated bone grafts remain, particularly undesirable mechanical properties and bioactivity to reproducibly regenerate new bone, and lack of surgical and clinical significance. To address these drawbacks, a freestanding 3D-printing bioscaffold with the biomimetic formulation and highly customized performance was developed. With the incorporation of urethane-based PEGylated poly(glycerol sebacate) (PEGSU) in ceramic bioinks, the resultant scaffolds can be printed with rapid self-prototyping in low temperature, exhibiting enhanced mechanical strength and hyperelasticity, and supporting cell proliferation and osteogenic differentiation. As indicated by in vivo experiments, the printed grid scaffolds can promote new bone formation in critical-sized cranial defects and thus providing instant protection for sensitive tissues after craniectomy. Furthermore, anatomically scaled craniomaxillofacial bone structures can be printed with high fidelity, and finite element analysis confirmed their routine functionalities after implantation. With these advantages, this self-standing 3D printed biomaterial shows great prospect of clinical application in craniomaxillofacial bone regeneration and provides new horizons for other complex reconstructions.