Xenofree Enzymatic Products for the Isolation of Human Adipose-Derived Stromal/Stem Cells

Human adipose-derived stromal/stem cells (ASCs) are an abundant, readily available population of adult stem cells that reside in adipose tissue and that have a great potential utility for tissue engineering and regenerative medicine therapeutic applications. Several preclinical studies have shown that ASCs have therapeutic applicability, but a standardized isolation and expansion methodology for clinical cell therapy has yet to be established. ASC are typically isolated and expanded using reagents with xenogenic components and this may pose certain risks and safety issues, such as exposure to infectious agents and immune reactions, creating further obstacles to the translation of ASC-based therapies to clinical scenarios. The objective of this study was to determine the suitability and efficacy of various alternative enzymatic products, CLS1 (Worthington), CLSAFA (Worthington), NB4 (SERVA), and Liberase (Roche), for the digestion of adipose tissue and subsequent isolation of ASCs, assessing cell functionality concerning their proliferation and differentiation ability. Results show that there are no statistically significant differences on yield and proliferation of cells isolated after enzymatic digestion with any of the studied products. The differentiation potential of the cells was not affected, and cell surface marker expression was similar among all products. We concluded that clinical grade products can replace current research-grade products effectively in our cell isolation protocols without any negative effect in the yield or function of human ASCs.