Bioceramic hydroxyapatite (HAp) has been extensively used as an additive to enhance hydrophilicity, osteoconductivity, and degradation rate of PCL. However, PCL has low adhesion due to its hydrophobic nature, which results in poor osteo-conduction properties and slow degradation. Polycaprolactone (PCL) is a widely used synthetic polymer in fabricating scaffolds because of its biocompatibility, high printability, and fast solidification after being extruded. For scaffold fabrication, appropriate material selection, architectural design, controlled chemistry, and interconnected porosity are key factors in achieving mechanical integrity, proper cellular activity, nutrient delivery/waste removal, bone ingrowth, and vascularization for the specific site of application. For BTE, biomedical scaffolds are a key component to provide a temporary environment for extracellular matrix formation, cellular activity, as well as mechanical support. īone tissue engineering (BTE), based on three-dimensional (3D) printing technology, has received increasing attention as a potential remedy to repair bone defects unable to be repaired on their own. However, the clinical usage of traditional treatments has been restricted due to associated drawbacks such as limited donor supply and donor sites, additional surgery, the potential risk of disease transmission, and immune response after implantation. Current treatments are mainly based on the use of traditional bone grafts such as autografts, allografts, and xenografts. Related, traumatic incidents in pelvic bone can be fatal. For instance, repairing a CSD in anatomical sites such as pelvis is important given it mainly consists of low-density trabecular bone covered by a thin layer of high-density cortical bone. Approximately two million bone grafts are annually implanted worldwide to repair bone defects. However, management of critical-sized defects (CSDs), which result from disease or a trauma, remains a substantial orthopedic challenge given that they cannot be spontaneously healed by the patient’s body and their repair needs surgical intervention. This study identified the effect of porosity and internal structure on scaffold mechanical properties and provided suggestions for developing scaffolds with mechanical properties for substituting trabecular bone.īone is a resilient tissue with self-healing capacity. Taken together, this study demonstrates that scaffolds printed from PCL/30% (wt.) nHAp with lattice and staggered structure offer promise for treating trabecular bone defects. Mechanical testing results also indicated elastic moduli and yield strength properties comparable to trabecular bone (elastic moduli: 14–165 MPa yield strength: 0.9–10 MPa). The lattice structure exhibited higher yield strength at all porosities. For elastic moduli, the two relationships intersected (porosity = 55%) such that the lattice structure exhibited higher moduli with porosity values greater than the intersection point vice versa for the staggered structure. Resultsĭifferent relationships between mechanical properties and porosities were noted for the staggered and lattice structures. Linear regression was used to evaluate mechanical properties as a function of scaffold porosity. Mechanical compressive testing was performed to determine scaffold elastic modulus and yield strength. Scaffolds with various porosities were designed and fabricated with and without an interlayer offset, termed as staggered and lattice structure, respectively. We fabricated composite scaffolds (which aimed to replicate trabecular bone) from polycaprolactone (PCL) reinforced with 30% (wt.) nano-hydroxyapatite (nHAp) by extrusion printing. The objective of this study was to investigate the influence of porosity and internal structure on the mechanical properties of scaffolds. Bone tissue engineering, based on three-dimensional (3D) printing technology, has emerged as a promising approach to treat bone defects using scaffolds.
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