Multi-functional variational porosity in bone tissue scaffolds

Commonly used homogeneous scaffolds do not capture the intricate spatial material concentration presented in bone internal architecture. On the other hand gradient in porosity along the internal scaffold architecture might contribute for performing diverse mechanical, biological and chemical functions of scaffold. Thus the need for reproducible and fabricatable scaffold design with interconnected and continuous pore and controllable gradient in porosity for tissue regeneration is obvious but is thwarted by design and fabrication limitations. In this work, a novel heterogeneous scaffold modeling approach has been proposed targeting the bio-mimetic porosity design. First, an optimum filament deposition angle has been determined in slices based on the contour geometry of targeted region. And the internal region has been discritized considering the homogeneity factor along the deposition angle. Finally, an area weight based approach has been used to generate the spatial porosity function that determines the filament deposition location for desired bio-mimetic porosity. The proposed methodology has been implemented an illustrative examples using computer simulation. A comparison result of effective porosity has been presented between proposed design model and conventional fixed filament distance scaffolds respectively. The result shows a significant error reduction towards the achieving bio-mimetic scaffold design concept and provides more control over the desired porosity level. Moreover, the resultant model can easily be fabricated with simple SFF processes.