Application of Three-Dimension Printing Nano-Carbonated-Hydroxylapatite to the Repair of Defects in Rabbit Bone

Abstract

Shujie Wang,1,2 Chunyan Shao,2 Xingkai Zhao,1 Yizhe Guo,1 Houhui Song,2 Lida Shen,3 Zhenlei Zhou,1 Zhen Li4,5 1College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, People’s Republic of China; 2College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang Agriculture and Forestry University, Hangzhou, Zhejiang, 311300, People’s Republic of China; 3College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, Jiangsu, 210016, People’s Republic of China; 4College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, People’s Republic of China; 5State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing, Jiangsu, 210008, People’s Republic of ChinaCorrespondence: Zhenlei Zhou, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, People’s Republic of China, Tel [phone], Email [email protected] Zhen Li, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, People’s Republic of China, Tel/Fax [phone], Email [email protected]: Hydroxylapatite (HAp) is a biodegradable bone graft material with high biocompatibility. However, the clinical application of HAp has been limited due to the poor absorption rate in vivo.Methods: In this study, carbonated hydroxylapatite (CHAp) with a chemical composition similar to natural bone was synthesized. HAp and CHAp scaffolds were fabricated by 3D printing. Each material was designed by two types of scaffold model with a maximum width of 8 mm and a thickness of 2 mm, ie, structure I (round shape) and structure II (grid shape). Then, the HAp scaffolds were loaded with lutein. These scaffolds were implanted into the 8 mm bone defect on the top of the rabbit skull within 3 hours in the morning. The curative effects of the scaffolds were assessed two months after implantation.Results: The 3D printed scaffolds did not cause severe inflammation or rejection after implantation. It showed that the porous structures allow bone cells to enter into the scaffolds. Furthermore, CHAp scaffolds were more biocompatible than HAp scaffolds, and showed a higher level of degradation and new bone formation after implantation. Structure II scaffolds with a smaller mineral content degraded faster than structure I, while structure I had better osteoconductive properties than structure II. Besides, the addition of lutein significantly enhanced the rate of new bone formation.Discussion: The uniqueness of this study lies in the synthesis of 3D printed CHAp scaffolds and the implantation of CHAp in rabbit bone defects. The incorporation of suitable carbonate and lutein into HAp can enhance the osteoinductivity of the graft, and CHAp has a faster degradation rate in vivo, all of which provide a new reference for the research and application of apatite-based composites.Keywords: bone, 3D printing, hydroxylapatite, lutein, repair

Keywords

• bone
• 3d printing
• hydroxylapatite
• lutein
• repair