粉末積層造形法を用いた人工骨成形法の提案成形骨の表面と内部の化学的組成

摘要

In this study, we proposed a powder-layered manufacturing process, a type of rapid prototypingtechnique, to produce desired bone shapes for transplants using biomaterial powder. In the experiments, we usedconventional inkjet-type equipment and orthopedic filling-paste powder (BIOPEX), mainly containing alpha-tribasic calcium phosphate as the forming material. To solidify the powder, we used a sodium chondroitin sulfate+ dibasic sodium succinate anhydride aqueous solution as the binder liquid. This paper discusses the results ofinvestigations on the internal and surface chemical characteristics of formed artificial bones, formed artificialbones hardened by immersion process, and paste type artificial bones used in clinical applications, to determinethe suitability of the immersion conditions. The bones were immersed for five hours in immersion fluid made ofwater and binder liquid at 90 C. To analyze the chemical constituent, X-ray diffraction and X-ray photoelectronspectroscopy were used. The results showed that the hydrate reaction caused by the application of the binderfluid during forming enhances hydroxyapatite (HA) concentration by about 6.5 times. With samples immersed inwater, HA was found internally as well as from the surface, the quantity of which was about 80%, 11 times morethan conventional paste type artificial bone. On the other hand, with the samples immersed in the binder fluid, noHA crystals were detected internally. The percentages of P and Ca present on the surface were minute. Given thehigh quantities of C, O, and Na present, the immersion process is thought to have formed a thin layer of binderfluid. These results from the experimental samples indicate that immersion in binder fluid which showed noproblems in terms of chemistry and strength is most appropriate for clinical applications.