Study On The Additive Manufacturing Process Of Artificial Bone Scaffolds Of Coral Imitation

Natural coral has a similar structure with human bone, and can be used to make artificial bones, which are known as important bone substitute materials. Natural coral has been used in clinical treatment for more than twenty years. But, the quality of the natural source of coral is very limited and has been banned from mining. Coral artificial bone has a slow biodegradation of the defects, hindering the growth of new bone. In order to explore the natural coral artificial bone substitute materials, this work proposed using 3D printing to fabricate natural calcium carbonate/biopolymer composite imitation coral porous structures, and then the surface of the 3D printing product was transformed into hydroxyapatite thin layer by heat exchange reaction. The hydroxyapatite thin layer was beneficial to the growth of cell attachment and the imitation coral artificial bone with the new bone metabolism rate.Selective Laser Sintering(SLS), belonging to 3D Printing(also termed as Additive Manufacturing) technology, uses a laser beam to sinter and stack powders layer by layer to form solid 3D products. SLS is capable of effectively controlling part structure and properties, and thus meeting the individual requirement of different patients. Therefore, it has been widely used in the biomedical field, such as manufacturing of tissue engineering scaffolds and medical implants. This work prepared cuttlebone/PLLA composites to simulate natural coral composition. The material system has good biological compatibility, in which cuttlebone is main ingredients for natural calcium carbonate and poly(L-lactic acid) is a biodegradable polymer material. SLS technology was used to manufacture the natural coral structures, and the calcium carbonate was partially converted to hydroxyapatite by hydrothermal reaction, and the degradation rate of the artificial bone was controlled by altering the degree of transformation. In the composites with the PLLA15 wt%, SLS process parameters including the laser power of 15 W, laser scanning speed of 1500 mm/s and 0.08 mm single layer thickness result in the better mechanical properties. Increasing the reaction temperature or prolonging the reaction time can increase the degree of hydrothermal reaction, and promote the transformation of calcium carbonate into hydroxyapatite.This work has the materials system innovation, and focuses on the study of the effects of the SLS and hydrothermal processes on the mechanical performance and the degree of hydroxylation. Then, the preparation process of imitation coral artificial bone preparation was optimized., Therefore, it shows scientific significance and engineering application value.