Key technology of 3D bio-printing and its application in orthopedics

Abstract

Bone defect repairing and reconstruction has been a hot research topic in orthopedics for a long time. Tissue engineering and stem cell technology have made a series of important achievements in promoting bone regeneration to treat bone defect. In recent years, 3D bio-printing, which combining with 3D printing, tissue engineering and stem cell technology, has significant advantages in optimizing the geometry, mechanical properties and biological functions of repairing tissue for bone defect by accurately controlling the shape and internal structure of scaffolds, and printing biomaterials, stem cells and (or) cells into three-dimensional biological functional structures. A series of important progress has been achieved. The common printing methods for bio-printing related to orthopedic include: Inkjet 3D bioprinting; microextrusion 3D bioprinting; laser-assisted 3D bioprinting; stereolithography; microvalve based 3D bioprinting. Various printing methods and principles are not the same, and each has advantages and disadvantages, and the applicable "bio ink" is also different. The key technologies of orthopedic bio-3D printing include: the methods of image data acquisition and 3D structure design; development and application of composite bio-scaffold materials suitable for 3D printing, tissue engineering and bone-enhancing effect; stem cell selection for ensuring graft biological performance and induced pluripotent stem cell technology; in vitro bioreactor technology for improving the maturity and biocharacterization of bioprinted tissues. The literature published in the field of biological 3D printing research has continued to grow at a high rate since 2008. Using the bibliometric analysis software VOSviewer to create a co-word matrix for high-frequency keywords and to draw a keyword co-occurrence network map analysis, biological 3D printing research hotspots are the use of tissue engineering methods to 3D printed tissue scaffolds, while studying cell survival and drug effects. The instruments and methods of bio-3D printing are also one of the research hotspots.