Internal Scaffold Architecture Designs using Lindenmayer Systems

Scaffolds with designed interior pore architecture, predefined porosity and a well interconnected predetermined channel network has been the favored design approach for tissue engineering applications. Solid freeform fabrication (SFF) technologies have provided the capability to fabricate scaffolds with desired design characteristics due to its integration with CAD enabled tools. However, currently the interior macro pore design of scaffolds have been limited to simple regular shapes of either squares or circles due to inadequate CAD capability. In this paper we seek to enhance the design of the scaffold architecture by the use of rewriting schemas such as Lindenmayer systems (Lsystems) which provide a powerful method to create complex branched networks. We have presented several exploratory case examples to show the applicability of using such rewriting systems to model nutrient delivery networks within hydrogel scaffolds without an overwhelming need for expensive computer hardware. Feasibility studies applying these systems to the fabrication of samples using an extrusion based SFF system is presented. The paper concludes by future research prospects in extending the concept of L-system design theory to newer applications.