Selective Laser Sintering Process Optimization for Layered Manufacturing of CAPA® 6501 Polycaprolactone Bone Tissue Engineering Scaffolds

Abstract

Tissue engineering combines principles of the life sciences and engineering to replace and repair damaged human tissue. Present tissue engineering methods generally require the use of porous, bioresorbable scaffolds to serve as temporary three-dimensional templates to guide cell attachment, differentiation, proliferation, and subsequent regenerate tissue formation. Such scaffolds are anticipated to play an important role in allowing physicians to simultaneously reconstruct and regenerate damaged human tissues such as bone, cartilage, ligament, and tendon. Recent research strongly suggests that the choice of scaffold material and its internal porous architecture significantly influence regenerate tissue structure and function. However, a lack of versatile biomaterials processing and manufacturing methods capable of meeting the complex geometric and compositional requirements of tissue engineering scaffolds has slowed progress towards fully testing these promising findings. It is widely accepted that layered manufacturing methods such as selective laser sintering (SLS) have the potential to address these requirements. We have investigated SLS as a technique to fabricate tissue engineering scaffolds composed of polycaprolactone (PCL), one of the most widely investigated biocompatible, bioresorbable materials for tissue engineering applications. In this article, we report on our development of optimal SLS processing parameters for CAPA® 6501 PCL powder using systematic factorial design of experiments. Using the optimal parameters, we manufactured test scaffolds with designed porous channels and achieved dimensional accuracy to within 3%–8% of design specifications and densities approximately 94% relative to full density. Finally, using the optimal SLS process parameters, we demonstrated the successful fabrication of bone tissue engineering scaffolds based on actual minipig and human condyle scaffold designs.