A non-enzymatic method for isolating human adipose tissue-derived stromal stem cells

Background aimsThe isolation of human adipose stromal/stem cells (ASCs) currently relies on the use of the enzyme collagenase, which digests the triple helix region of peptide bonds in the collagen of adipose tissue. Collagenase is an expensive reagent derived from a bacterial source, and its use in isolating ASCs is a time-consuming procedure. This experiment evaluated the extraction of ASCs without an enzymatic digest.MethodsWe used a simple method of washing adipose tissue to isolate and characterize the cells and compared this method with the enzymatic procedure in terms of processing time, stem cell yield, differentiation potential and immunophenotype.ResultsBased on fluorescence activated cell sorting analysis, the stromal vascular fractions isolated with the washing method displayed a distinct and potentially favorable immunophenotype relative to the collagenase digestion. This difference may reflect the absence of chemical alteration of the cells by collagenase digestion. Independent of the isolation procedure, the resulting passaged ASCs were comparable based on immunophenotype and adipogenic and osteogenic differentiation potential.ConclusionsAlthough using collagenase substantially increases cell yield, the two methods yield a similar cell product.