title: Three-dimensional printing akermanite porous scaffolds for load-bearing bone defect repair: An investigation of osteogenic capability and mechanical evolution.
abstract: Some Ca-Mg-silicate ceramics have been widely investigated to be highly bioactive and biodegradable, whereas their osteogenic potential and especially biomechanical response in the early stage in vivo are scarcely demonstrated. Herein, the osteogenesis capacity and mechanical evolution of the akermanite (Ca2MgSi2O7) porous materials manufactured by ceramic ink writing three-dimensional printing technique were investigated systematically in a critical size femur defect model, in comparison with the clinically available β-tricalcium phosphate porous bioceramic. Such three-dimensional printed akermanite scaffolds possess fully interconnected pores of ∼280 × 280 µm in size and over 50% porosity with appreciable compressive strength (∼71 MPa), that is 7-fold higher than that of the β-tricalcium phosphate porous bioceramics (∼10 MPa). After 6 weeks and 12 weeks of implantation, the percentage of newly formed bone and more new bone was observed in the akermanite group as compared with the β-tricalcium phosphate group (p < 0.01). Moreover, significant higher mRNA expressions of osteogenic genes were detected in the akermanite group by PCR analysis (p < 0.01). The in vivo mechanical strength decreased during the process of implantation, but maintained a relative high level (∼14 MPa) which was still higher than that of the host cancellous bone (5-10 MPa) at 12 weeks post-implantation. On the contrary, the β-tricalcium phosphate scaffold always exhibited a very low mechanical strength (∼8 MPa). These results suggest that the three-dimensional printed akermanite scaffolds are promising for the bone tissue regeneration and repair of load-bearing bone defects.
authors: Department of Orthopaedic Surgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
authors: An
authors: A
authors: Liu
authors: Department of Oral and Maxillofacial Surgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
authors: Miao
authors: M
authors: Sun
authors: Bio-nanomaterials and Regenerative Medicine Research Division, Zhejiang-California International Nanosystem Institute, Zhejiang University, Hangzhou, China.
authors: Xianyan
authors: X
authors: Yang
authors: Department of Orthopaedic Surgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
authors: Chiyuan
authors: C
authors: Ma
authors: Department of Oral and Maxillofacial Surgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
authors: Yanming
authors: Y
authors: Liu
authors: Department of Orthopaedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan, China.
authors: Xu
authors: X
authors: Yang
authors: Department of Orthopaedic Surgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China 11318143@zju.edu.cn.
authors: Shigui
authors: S
authors: Yan
authors: Bio-nanomaterials and Regenerative Medicine Research Division, Zhejiang-California International Nanosystem Institute, Zhejiang University, Hangzhou, China zhrgou@zju.edu.cn.
authors: Zhongru
authors: Z
authors: Gou
mesh_terms: D000818:Animals; D018786:Bone Substitutes / Q000138:chemical synthesis; D002130:Calcium Phosphates / Q000627:therapeutic use*; D002516:Ceramics / Q000737:chemistry*; D019245:Compressive Strength; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005264:Femoral Fractures / Q000473:pathology / Q000503:physiopathology* / Q000628:therapy*; D008297:Male; D008422:Materials Testing; D010012:Osteogenesis; D016062:Porosity; D011312:Pressure; D066330:Printing, Three-Dimensional; D011817:Rabbits; D013314:Stress, Mechanical; D054457:Tissue Scaffolds; D016474:Weight-Bearing
chemical_list: D018786:Bone Substitutes; D002130:Calcium Phosphates; C485817:beta-tricalcium phosphate; C023506:Glass ceramics
keywords: Akermanite; load-bearing bone defect; mechanical evolution; osteogenic capability; three-dimensional printing scaffold