An alternative method for the isolation of mesenchymal stromal cells derived from lipoaspirate samples.

Background Aims: Since initial methods were developed for isolating cells from adipose tissue, little has been done to improve mesenchymal stromal cell (MSC) yield. The aim of the present study was to isolate a population of MSC from lipoaspirate samples without tissue digestion and to assess the possibility of cryopreserving the freshly isolated cells.

Methods: A population of MSC was isolated from 13 patients' lipoaspirate samples by mechanical dissociation. Mechanically processed lipoaspirate adipose tissue (MPLA) cells were characterized after in vitro cell expansion by morphologic analysis, expression of MSC surface markers and differentiation assays.

Results: Mechanical dissociation yielded a large quantity of adherent MSC both after standard and vibro-assisted liposuction. Preservation of lipoaspirate samples at 4 degrees C for 1 or 2 days until the mechanical procedure did not change the MPLA cell content. It was possible to store freshly isolated MPLA cells by cryopreservation without loss of the MSC population. Adherent MPLA cells were negative for CD45 and CD31 and positive for CD34, CD105, CD44 and CD90. They also showed adipogenic, osteogenic and chondrogenic potentials similar to MSC populations from other sources as already described in the literature.

Conclusions: MSC can be isolated from human lipoaspirate samples by the mechanical procedure described in this study with a significant reduction in time and cost. Together with cryopreservation of freshly isolated MPLA cells, this has made it easier to harvest and store MSC for therapeutic applications such as soft-tissue augmentation and tissue engineering.