There are two important factors to overcome spinal tuberculosis, i.e. killing and preventing the Mycobacterium tuberculosis to spread, also replacing and reconstructing the damaged bone. A study of biomaterial field has already invented a bone graft which could also take a role as an antibiotic drug delivering system to the bacteria, called Injectable Bone Substitute (IBS). This product offers an effective treatment because it could fill and adjust the space left by the infected bone along with delivering the drug needed. On the other side, the tissue engineering field keeps developing a scaffold for a biodegradable artificial supporting structure that could stimulate new bone tissue regeneration. For a fast, easy, cheap but satisfying result of the scaffold fabrication, in recent years, researchers start to utilize the 3D printing technology. This technology enables to produce an accurate custom bone scaffold by design.

 

This study focused on an innovation to overcome the spinal tuberculosis problem by combining the IBS and 3D printed bone scaffold. This innovation could provide a local drug delivery system along with tissue regeneration and bone reconstruction. In this study, 5 pore size variations of 3D printed bone scaffold which have been injected with IBS were tested. The bone scaffold was fabricated from Polylactide acid (PLA) filament using FDM method through an ordinary commercial 3D printer. The IBS was synthesized from nanohydroxyapatite, gelatin, streptomycin, and HPMC. The physical characterization performed in this study were functional group test, porosity test, degradation test and morphology test.

 

The 3D printed bone scaffold was tested by using FTIR to observe the specific functional group of PLA. There was significant C-O bond at 131.78 until 1041.74 cm^-1 and C=O bond at 1744.57 cm^-1. After IBS injection, the bone scaffold was also tested by using FTIR. The data showed that there were specific functional groups of each constituent material. The ether functional group from streptomycin was found at 1078.22 and 1038.28 cm^-1. There were also specific functional groups for nano hydroxyapatite, gelatin and HPMC. The 3D printed bone scaffold’s morphology could be observed macroscopically. The pores have satisfactorily printed as if the design which has been made. The size of the pore designed would influence the porosity of the scaffold. The data indicated a positive trend correlation between the pore size and the porosity of scaffold. The scaffold was meant to be a biodegradable material. The degradation test has proven that the PLA based- scaffold could be degraded in Phosphate Buffer Saline (PBS), which represented the body fluid, exhibited by its decreasing pH value.

In conclusion, 3D printing technology could be potentially utilized in medical area, especially to overcome spina. The IBS associated- 3D printed bone scaffold is a potential alternative regarding to this case. For future study, there is still a need to develop this research to know whether the scaffold could really control the drug release by its pore size and design.