American Dental Association Science and Research Institute, Gaithersburg, MD 20899, United States of America.
Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, United States of America.
Biomed Mater. 2021 Mar 8;16(4). doi: 10.1088/1748-605X/abcf03.
Biofabrication has been adapted in engineering patient-specific biosynthetic grafts for bone regeneration. Herein, we developed a three-dimensional (3D) high-resolution, room-temperature printing approach to fabricate osteoconductive scaffolds using calcium phosphate cement (CPC). The non-aqueous CPC bioinks were composed of tetracalcium phosphate, dicalcium phosphate anhydrous, and Polyvinyl butyral (PVB) dissolved in either ethanol (EtOH) or tetrahydrofuran (THF). They were printed in an aqueous sodium phosphate bath, which performs as a hardening accelerator for hydroxyapatite formation and as a retainer for 3D microstructure. The PVB solvents, EtOH or THF, affected differently the slurry rheological properties, scaffold microstructure, mechanical properties, and osteoconductivity. Our proposed approach overcomes limitations of conventional fabrication methods, which require high-temperature (>50 °C), low-resolution (>400 μm) printing with an inadequate amount of large ceramic particles (>35 μm). This proof-of-concept study opens venues in engineering high-resolution, implantable, and osteoconductive scaffolds with predetermined properties for bone regeneration.
生物制造已被应用于工程特定患者的生物合成移植物，以促进骨再生。在此，我们开发了一种三维（3D）高分辨率、室温打印方法，使用磷酸钙水泥（CPC）制造骨传导支架。非水相 CPC 生物墨水由磷酸四钙、无水磷酸二钙和溶解在乙醇（EtOH）或四氢呋喃（THF）中的聚丁基乙烯（PVB）组成。它们在磷酸钠水溶液中打印，该溶液在促进羟基磷灰石形成和保留 3D 微观结构方面发挥着硬化加速剂的作用。PVB 溶剂，乙醇或四氢呋喃，对浆料流变性、支架微观结构、力学性能和骨传导性有不同的影响。我们提出的方法克服了传统制造方法的局限性，这些方法需要高温（>50°C）、低分辨率（>400μm）打印和大量大陶瓷颗粒（>35μm）的不足。这项概念验证研究为工程学提供了新的途径，可制造具有预定特性的高分辨率、可植入和骨传导性支架，以促进骨再生。
