3D Printing of PolyLactic Acid (PLA) Scaffold Combined with Injectable Bone Substitute (IBS) for Tuberculosis Drug Delivery

Abstract

Spinal tuberculosis is one of the infectious diseases which according to the World Health Organization (WHO), is a major cause of health problems and one of the top 10 causes of death worldwide. The aim of this study was to fabricate a 3D printing scaffold with the design of truncated hexahedron, then combined with Injectable Bone Substitute (IBS) paste as a method for drug delivery in the case of spinal tuberculosis. Injectable Bone Substitute (IBS) paste was synthesized by combining some materials including hydroxyapatite, gelatin, hydroxypropyl methylcellulose (HPMC), and streptomycin. The scaffold was characterized with IBS paste through the digital microscope and the mechanical test to determine the mechanical strength of the scaffold. The results of the 3D printing scaffold showed that the scaffold has interconnectivity between pores. After being injected with IBS, it was seen that the entire surface of the scaffold pores was covered by IBS paste evenly. Scanning Electron Microscope (SEM) tests showed that the surface of the scaffold has been covered by IBS paste, and proves that the pores are still formed. Energy Dispersive X-Ray (EDX) test results showed that the IBS paste containing a hydroxyapatite component consisting of Ca, P, and O elements. Mechanical tests showed that the scaffold for all pore sizes had a compressive strength of 1.49-3.97 MPa before IBS injection and increased to 3.45-4.77 MPa after IBS injection. Then the bending test showed that the scaffold had a bending strength of 16.76-36.09 MPa and increased to around 21.57-40.36 MPa after being injected with IBS. The drug release test showed that the 3D printing scaffold could release streptomycin by 4.944%-6.547%, which has met the percentage of drug release that is able to kill tuberculosis bacteria. It can be concluded that 3D printing scaffold combined with IBS paste can be applied as a drug carrier as well as a method of healing spinal tuberculosis.