Low-Temperature Additive Manufacturing of Biomimic Three-Dimensional Hydroxyapatite/Collagen Scaffolds for Bone Regeneration

• DOI: 10.1021/acsami.6b00815
• Publication Date: 2016-03-01T23:47:52Z
• Authors: Kai-Feng Lin; Shu He; Yue Song; Chun-Mei Wang; Yi Gao; Jun-Qin Li; Peng Tang; Zheng Wang; Long Bi; Guo-Xian Pei
• Keywords: Male; Bone Regeneration; Tissue Scaffolds; Bone Marrow Cells; 02 engineering and technology; Durapatite; Biomimetic Materials; Bone Substitutes; Animals; Cattle; Collagen; Femur; Rabbits; Stromal Cells; 0210 nano-technology; Cells, Cultured; Cell Proliferation

Low-temperature additive manufacturing (AM) holds promise for fabrication of three-dimensional (3D) scaffolds containing bioactive molecules and/or drugs. Due to the strict technical limitations of current approaches, few materials are suitable for printing at low temperature. Here, a low-temperature robocasting method was employed to print biomimic 3D scaffolds for bone regeneration using a routine collagen-hydroxyapatite (CHA) composite material, which is too viscous to be printed via normal 3D printing methods at low temperature. The CHA scaffolds had excellent 3D structure and maintained most raw material properties after printing. Compared to nonprinted scaffolds, printed scaffolds promoted bone marrow stromal cell proliferation and improved osteogenic outcome in vitro. In a rabbit femoral condyle defect model, the interconnecting pores within the printed scaffolds facilitated cell penetration and mineralization before the scaffolds degraded and enhanced repair, compared to nonprinted CHA scaffolds. Additionally, the optimal printing parameters for 3D CHA scaffolds were investigated; 600-μm-diameter rods were optimal in terms of moderate mechanical strength and better repair outcome in vivo. This low-temperature robocasting method could enable a variety of bioactive molecules to be incorporated into printed CHA materials and provides a method of bioprinting biomaterials without compromising their natural properties.