A Simple Method to Determine the Purity of Adipose-Derived Stem Cell-Based Cell Therapies.

: It is important to standardize methods to quantify the purity of adipose tissue-derived cells for regenerative medicine. We developed a simple and robust tool to discriminate fibroblasts and adipose stem cells (ASCs) by testing release of specific growth factors. ASCs and dermal fibroblasts (DFs) were isolated from human donors (n = 8). At passage 4, cultures were prepared with progressive ASC/DF ratios of 100%/0%, 75%/25%, 50%/50%, 25%/75%, and 0%/100% for each donor and incubated in hypoxic chambers at 0.1% and 5% O SIGNIFICANCE: In order to provide direction to academia, industry, and regulatory authorities regarding purity assessment for adipose tissue-derived cells, this report describes a simple tool to facilitate development of international standards based on reproducible parameters and endpoints that may systematize cellular products across boundaries and accelerate the delivery of safe and effective adipose stem cell (ASC)-based tools to the medical community and the patients it serves. This tool (a) can discriminate specifically fibroblasts and ASCs and (b) can be rapidly implemented and performed before the release of the ASC-based therapy (a response within 24 hours).