Workshop on the characterization of fiber-based scaffolds: Challenges, progress, and future directions.

A critical component of many tissue-engineered medical products (TEMPs) is the scaffold or biomaterial. The industry's understanding of scaffold properties and their influence on cell behavior has advanced, but our technical capability to reliably characterize scaffolds requires improvement, especially to enable large-scale manufacturing. In response to the key findings from the 2013 ASTM International Workshop of Standards and Measurements for Tissue Engineering Scaffolds, the National Institute of Standards and Technology (NIST), ASTM International, BiofabUSA, and the Standards Coordinating Body (SCB) organized a workshop in 2018 titled, "Characterization of Fiber-Based Scaffolds". The goal was to convene a group of 40 key industry stakeholders to identify major roadblocks in measurements of fiber-based scaffold properties. This report provides an overview of the findings from this collaborative workshop. The four major consensus findings were that (a) there is need for a documentary standard guide that would aid developers in the selection of test methods for characterizing fiber-based scaffolds; (b) there is a need for a strategy to assess the quality of porosity and pore size measurements, which could potentially be ameliorated by the development of a reference material; (b) there are challenges with the lexicon used to describe and assess scaffolds; and (d) the vast array of product applications makes it challenging to identify consensus test methods. As a result of these findings, a working group was formed to develop an ASTM Standard Guide for Characterizing Fiber-Based Constructs that will provide developers guidance on selecting measurements for characterizing fiber-based scaffolds.