The design of pores in PCL/HA-associated PLA scaffold with 3D printing method

Abstract

The 3D printing application in tissue engineering is developing rapidly in the era of Industrial Revolution 4.0 (IR 4.0). One of its applications is in producing architectural design of scaffold. This scaffold could be designed based on the bone defect cases, which could be caused by injury, bone cancer, skeletal tuberculosis, and other bone abnormalities. 3D printing could possibly be used for designing pore sizes and shapes that support space availability in bone cell regeneration. This study aimed to design the scaffold's geometry of pore unit and size, which was printed using 3D Printing FDM (Fused Deposition Modeling) with filament Polylactic Acid (PLA). Samples were made in 2 groups, 1st group was the group of PLA scaffolds without fillers with pore size designs of 300 µm, 500 µm, 700 µm. While, the 2nd group was the group of PLA scaffolds filled by polycaprolacton (PCL) / hydroxyapatite (HA) with pore size designs of 1000 µm, 1200 µm, and 1400 µm. The composition of the PCL / HA fillers used was (90:10)% wt. Sample characterization included pore size test using Scanning Electron Microscope (SEM), porosity, compressive strength and degradability. The characterizations were carried out to determine their suitability for the bone scaffold application. The pore size test of the 1st group showed that the 300 µm pore design could not be measured because it was too small. Meanwhile, the pore size designs of 500 µm and 700 µm were measured and resulted 476.64 µm, and 696.955 µm. The porosity test obtained the data of porosity respectively 2.625%, 3.375% and 3.875%. The results of compressive strength test of the scaffolds were between 65.902– 102.016 MPa. As for the 2nd group, the PLA-PCL / HA scaffolds samples were measured their pore sizes and resulted 658.85 µm, 1,080.00 µm and 1,230.54 µm respectively. Furthermore, the porosity test showed that the the porosity of the 2nd group was decreased if it was compared by the 1st group, i.e. 1,500%, 1.875% and 2.125%, respectively. The results of the compressive strength test were in the range of 86.840 – 162.379 MPa. The 1st and 2nd group showed the largest percentage of lost mass were 6.675% and 3.051% respectively, in 3 weeks. In conclusion, from all of the scaffold designs, the PLA-PCL / HA scaffolds with 1,000 µm pore design were the most suitable for mandibular cortical bone because of its characteristics, i.e. the 684.210 µm of pore size, degraded 3.051% in 21 days, compressive strength of 162.379 MPa and porosity of 1.500%.