IADR Abstract Archives
Comparison of mechanical properties in four 3D printable scaffold-biocomposites
Objectives: Poly(L-lactic) Acid (PLLA) scaffold and the metal-oxide (i.e. silica (SiO2), zirconia (ZrO2) and hafnia (HfO2)) loaded scaffold-biocomposites have been 3D-printed successfully via electrospinning, and also previously shown a significant enhancement in the osteogenesis that might play important roles in various applications, such as tissue reconstruction, bone guidance and regeneration. To accommodate these application needs, this research was done to investigate the mechanical properties, in terms of microhardness and tensile strength, about these PLLA scaffold-biocomposites.
Methods: Four types of PLLA scaffold-biocomposites (PLLA, PLLA/SiO2, PLLA/ZrO2 and PLLA/HfO2), were prepared in sheets according to a previous report. Vickers hardness was tested (n=12-14) by applying indenter to sample with 0.245N for 10 seconds, and indentation was measured under optical microscope (Leica, Germany) with magnification ×50. For tensile strength, it was calculated by subjecting sample (n=5-6) to tensile force using Universal testing Machine (Instron 4444, USA), divided by the cross-sectional area (width × thickness) of each piece of sample. One-way ANOVA and Welch's t-test were used to compare the difference among four groups and between two groups, respectively, using Excel 2013 (Microsoft, USA) at α=0.05.
Results: Statistical significant difference (p~5.18x10-13) in average(±SD) Vickers hardness among the four different scaffold-biocomposites was recorded, with the order of PLLA/HfO2 (0.419±0.159HV) > PLLA/ZrO2 (0.144±0.042HV) = PLLA/SiO2 (0.121±0.060HV) > PLLA (0.069±0.013HV). Only the hardness between PLLA/ZrO2 and PLLA/SiO2 groups does not show a statistical significant difference (p=0.277). For average tensile strength, the order is PLLA/HfO2 (1.716±0.265MPa) > PLLA (1.287±0.314MPa) = PLLA/SiO2 (1.200±0.333MPa) = PLLA/ZrO2 (1.198±0.340MPa). PLLA/HfO2 has a statistically higher tensile strength than others (p<0.05), whilst no statistical difference (p>0.05) was found between PLLA, PLLA/SiO2 and PLLA/ZrO2.
Conclusions: Mechanical strength of scaffold-biocomposites could be modified successfully by the addition of metal oxides. Meanwhile, PLLA/HfO2 has the highest hardness and tensile strength when comparing to other scaffold-biocomposites.
Methods: Four types of PLLA scaffold-biocomposites (PLLA, PLLA/SiO2, PLLA/ZrO2 and PLLA/HfO2), were prepared in sheets according to a previous report. Vickers hardness was tested (n=12-14) by applying indenter to sample with 0.245N for 10 seconds, and indentation was measured under optical microscope (Leica, Germany) with magnification ×50. For tensile strength, it was calculated by subjecting sample (n=5-6) to tensile force using Universal testing Machine (Instron 4444, USA), divided by the cross-sectional area (width × thickness) of each piece of sample. One-way ANOVA and Welch's t-test were used to compare the difference among four groups and between two groups, respectively, using Excel 2013 (Microsoft, USA) at α=0.05.
Results: Statistical significant difference (p~5.18x10-13) in average(±SD) Vickers hardness among the four different scaffold-biocomposites was recorded, with the order of PLLA/HfO2 (0.419±0.159HV) > PLLA/ZrO2 (0.144±0.042HV) = PLLA/SiO2 (0.121±0.060HV) > PLLA (0.069±0.013HV). Only the hardness between PLLA/ZrO2 and PLLA/SiO2 groups does not show a statistical significant difference (p=0.277). For average tensile strength, the order is PLLA/HfO2 (1.716±0.265MPa) > PLLA (1.287±0.314MPa) = PLLA/SiO2 (1.200±0.333MPa) = PLLA/ZrO2 (1.198±0.340MPa). PLLA/HfO2 has a statistically higher tensile strength than others (p<0.05), whilst no statistical difference (p>0.05) was found between PLLA, PLLA/SiO2 and PLLA/ZrO2.
Conclusions: Mechanical strength of scaffold-biocomposites could be modified successfully by the addition of metal oxides. Meanwhile, PLLA/HfO2 has the highest hardness and tensile strength when comparing to other scaffold-biocomposites.