Tissue Engineering is an interdisciplinary field which applies the principles of engineering and the life sciences towards the development of biological substitutes that restore, maintain, or improve tissue function. Especially bone tissue is organized into cancellous or cortical bone. Cancellous bone (trabecular bone or spongy bone), is porous, providing structural support and organization for bone marrow interspersed inside. In contrast, cortical bone is the compact bone surrounding the marrow space, and confers mechanical strength to bone. In recent, bone tissue engineering has the focus on regeneration of the damaged bone tissue. So, the development of scaffold is an increasing for damage and disease bone tissue.
A Scaffold in tissue engineering serves as a temporary skeleton to accommodate and stimulate new tissue growth. The role of scaffold is to guide cell morphology, migration and proliferation. The scaffold for tissue regeneration application should be biocompatible, biodegradable and have an adequate mechanical characteristic. Also, scaffold should have pore of satisfactory quantity and interconnection. To fabricate 3D scaffold for tissue engineering, traditional fabrication methods have been developed. These methods include particulate leaching, gas forming, freeze drying, phase separation and so on. However, it is difficult to fabricate the scaffold with interconnected pore and complex geometry. Recently, scaffold fabrication technology using 3D printer based on rapid prototyping was developed for the damaged tissue regeneration such as stereolithography (SLA), selective laser sintering (SLS) and fused deposition modeling (FDM). These technologies permit researchers to control the parameters of scaffold such as pore size, porosity, and interconnectivity.
In this study, we used the polymer deposition system (PDS) based on rapid prototyping (RP) to fabricate the 3D scaffold and then fabricated dual pore on 3D scaffold by salt leaching method. The used materials were polycaprolactone (PCL) and sodium chloride (NaCl). The 3D dual pore scaffolds were fabricated according to blending ratio such as PCL (70 wt%)/NaCl 100 (30 wt%), PCL (50 wt%)/NaCl 100 (50 wt%), PCL (70 wt%)/NaCl 45 (30 wt%), and PCL (50 wt%)/NaCl 45 (50 wt%).
The 3D dual pore scaffold was observed by SEM-EDS (scanning electron microscope-energy dispersive spectroscopy). The results showed that 3D dual pore scaffolds had a deposition width of 500 μm and contained a pore size of 500 μm and below 100 μm. To evaluate the 3D dual pore scaffolds for bone tissue regeneration, we carried out the cell proliferation experiment using a CCK-8 and the mechanical strength test using a universal testing machine. In summary, the 3D dual pore scaffold was found to be suitable for human cancellous bone in accordance with the result of in-vitro and mechanical strength. Thus, 3D dual pore scaffold could be a promising approach for effective bone regeneration.