Methodology for Evaluating Candidate Geometric Reference Scaffolds

Along with the ASTM Division IV subcommittee on Tissue Engineered Medical Products, the National Institute of Standards and Technology is developing a geometric reference scaffold. This paper describes the methodology applied to the three different types of candidate reference scaffolds to quantify their structure and rank them according to quality metrics. In this work, we detail this methodology using the candidate reference scaffold produced by stereolithography. We perform X-ray micro-computed tomography on three of the manufactured scaffolds and compute total porosity, pore size distribution, and pore length for each. We compare these quantities to those of the model scaffold using statistical measures of variational distance, relative uncertainty, and uniformity. Through this evaluation, we find that the scaffold produced by stereolithography agrees well with its model and merits further consideration as a reference scaffold.