Computed Post-analyses on the Morphology of Hydroxyapatite Coated Poly(lactic acid) Scaffolds

Adequate pore size of bone scaffold is crucial for cell migration. However, too small or too large pores might give negative effects on cell integration within the scaffold microstructure. Therefore, analysis on the influence of fabrication parameter/technique towards the pore size of bone scaffolds is necessary to be conducted. In this study, polylactic acid (PLA) was used as the base material to fabricate three-dimensional (3D) scaffold using 3D printing technique at different pore sizes and strut sizes (400:600, 400:900, 600:600 and 600:900). The usage of 3D printing grants the ability to develop porous scaffold structure. The scaffolds were then coated with bioactive hydroxyapatite (HA) for the enhancement of biological and mechanical properties. The morphology of the scaffold surfaces was visualized under field emission scanning electron microscope (FESEM). In this study, computed post-analyses on the FESEM morphology structure were conducted by analyzing the pore size, porosity and HA diameter using ImageJ and MATLAB software. The pore size of the scaffolds became smaller following the formation of HA nucleated coating layer. The 600:600 scaffolds have the highest porosity followed by the 600:900, 400:600 and 400:900 scaffolds. Increase in pore/strut size led to larger HA nucleation due to the decrement in number of pores which in turn decreased the surface area for coating formation. The largest HA nucleation size was found on the 600:900 scaffolds. Thus, the morphology and the size of the nucleated HA were affected by different pore and strut sizes of the 3D printed scaffolds.