Dual-Nozzle 3D Printed Nano-Hydroxyapatite Scaffold Loaded with Vancomycin Sustained-Release Microspheres for Enhancing Bone Regeneration

Jianyi Li,1,* Keke Li,2,* Yukun Du,1,* Xiaojie Tang,3,* Chenjing Liu,1 Shannan Cao,3 Baomeng Zhao,2 Hai Huang,3 Hongri Zhao,3 Weiqing Kong,1 Tongshuai Xu,3 Cheng Shao,1 Jiale Shao,1 Guodong Zhang,4 Hongbo Lan,5 Yongming Xi1 1Department of Orthopaedic Surgery, the Affiliated Hospital of Qingdao University, Qingdao, People’s Republic of China; 2Yantai Campus of Binzhou Medical University, Yantai, People’s Republic of China; 3Yantai Affiliated Hospital of Binzhou Medical University, Yantai, People’s Republic of China; 4Tengzhou Central People’s Hospital, Tengzhou, People’s Republic of China; 5Shandong Engineering Research Center for Additive Manufacturing Qingdao University of Technology, Qingdao, People’s Republic of China*These authors contributed equally to this workCorrespondence: Yongming Xi, Department of Orthopaedic Surgery, the Affiliated Hospital of Qingdao University, Qingdao, 266071, People’s Republic of China, Email xym700118@163.com Hongbo Lan, Shandong Engineering Research Center for Additive Manufacturing Qingdao University of Technology, Qingdao, 266520, People’s Republic of China, Email hblan99@126.comBackground: Successful treatment of infectious bone defect remains a major challenge in the orthopaedic field. At present, the conventional treatment for infectious bone defects is surgical debridement and long-term systemic antibiotic use. It is necessary to develop a new strategy to achieve effective bone regeneration and local anti-infection for infectious bone defects.Methods: Firstly, vancomycin / poly (lactic acid-glycolic acid) sustained release microspheres (VAN/PLGA-MS) were prepared. Then, through the dual-nozzle 3D printing technology, VAN/PLGA-MS was uniformly loaded into the pores of nano-hydroxyapatite (n-HA) and polylactic acid (PLA) scaffolds printed in a certain proportion, and a composite scaffold (VAN/MS-PLA/n-HA) was designed, which can not only promote bon