title: Lightweight Open-Cell Scaffolds from Sea Urchin Spines with Superior Material Properties for Bone Defect Repair.
abstract: Sea urchin spines (Heterocentrotus mammillatus), with a hierarchical open-cell structure similar to that of human trabecular bone and superior mechanical property (compressive strength ∼43.4 MPa) suitable for machining to shape, were explored for potential applications of bone defect repair. Finite element analyses reveal that the compressive stress concentrates along the dense growth rings and dissipates through strut structures of the stereoms, indicating that the exquisite mesostructures play an important role in high strength-to-weight ratios. The fracture strength of magnesium-substituted tricalcium phosphate (β-TCMP) scaffolds produced by hydrothermal conversion of urchin spines is about 9.3 MPa, comparable to that of human trabecular bone. New bone forms along outer surfaces of β-TCMP scaffolds after implantation in rabbit femoral defects for one month and grows into the majority of the inner open-cell spaces postoperation in three months, showing tight interface between the scaffold and regenerative bone tissue. Fusion of beagle lumbar facet joints using a Ti-6Al-4V cage and β-TCMP scaffold can be completed within seven months with obvious biodegradation of the β-TCMP scaffold, which is nearly completely degraded and replaced by newly formed bone ten months after implantation. Thus, sea urchin spines suitable for machining to shape have advantages for production of biodegradable artificial grafts for bone defect repair.
authors.affiliation: Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences , Shenyang, Liaoning 110016, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Cao
authors.affiliation: Department of Orthopedics, Xijing Hospital, The Fourth Military Medical University , Xi'an, Shaanxi 710032, China.
authors.forename: Xiaokang
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Orthopedics, The First Hospital of China Medical University , Shenyang, Liaoning 110001, China.
authors.forename: Xiaoshu
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Department of Orthopedics, Xijing Hospital, The Fourth Military Medical University , Xi'an, Shaanxi 710032, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Li
authors.affiliation: NanoEngineering Department, University of California, San Diego , La Jolla, California 92093, United States.
authors.forename: Kenneth S
authors.initials: KS
authors.lastname: Vecchio
authors.affiliation: Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences , Shenyang, Liaoning 110016, China.
authors.forename: Lina
authors.initials: L
authors.lastname: Yang
authors.affiliation: Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences , Shenyang, Liaoning 110016, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Cui
authors.affiliation: Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences , Shenyang, Liaoning 110016, China.|School of Materials Science, University of Science and Technology of China , Hefei, Anhui 230026, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Yang
authors.affiliation: Department of Orthopedics, The First Hospital of China Medical University , Shenyang, Liaoning 110001, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Department of Orthopedics, Xijing Hospital, The Fourth Military Medical University , Xi'an, Shaanxi 710032, China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Guo
authors.affiliation: Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences , Shenyang, Liaoning 110016, China.|School of Materials Science, University of Science and Technology of China , Hefei, Anhui 230026, China.
authors.forename: Xing
authors.identifier: http://orcid.org/0000-0002-6634-4338
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000818:Animals; D002130:Calcium Phosphates; D019245:Compressive Strength; D004285:Dogs; D006801:Humans; D010012:Osteogenesis; D016062:Porosity; D011817:Rabbits; D012617:Sea Urchins; D054457:Tissue Scaffolds
chemical_list: D002130:Calcium Phosphates
keywords: bone defect repair; finite element analysis; lightweight scaffolds; mechanical property; open-cell structure; sea urchin spines