Impact of the Different Preparation Methods to Obtain Human Adipose-Derived Stromal Vascular Fraction Cells (AD-SVFs) and Human Adipose-Derived Mesenchymal Stem Cells (AD-MSCs): Enzymatic Digestion Versus Mechanical Centrifugation

Autologous therapies using adipose-derived stromal vascular fraction (AD-SVFs)and adult adipose-derived mesenchymal stem cells (AD-MSCs) warrant carefulpreparation of the harvested adipose tissue. Currently, no standardized techniquefor this preparation exists. Processing quantitative standards (PQSs) definemanufacturing quantitative variables (such as time, volume, and pressure).Processing qualitative standards (PQLSs) define the quality of the materials and methods in manufacturing. The purpose of the review was to use PQSs and PQLSs to report the in vivo and in vitro results obtained by different processing kitsthat use different procedures (enzymatic vs. non-enzymatic) to isolate humanAD-SVFs/AD-MSCs. PQSs included the volume of fat tissue harvested and reagentsused, the time/gravity of centrifugation, and the time, temperature, and tiltlevel/speed of incubation and/or centrifugation. PQLSs included the use of acollagenase, a processing time of 30 min, kit weight, transparency of the kitcomponents, the maintenance of a closed sterile processing environment, and theuse of a small centrifuge and incubating rocker. Using a kit with the PQSs andPQLSs described in this study enables the isolation of AD-MSCs that meet theconsensus quality criteria. As the discovery of new critical quality attributes(CQAs) of AD-MSCs evolve with respect to purity and potency, adjustments to thesebenchmark PQSs and PQLs will hopefully isolate AD-MSCs of various CQAs withgreater reproducibility, quality, and safety. Confirmatory studies will no doubt need to be completed.