D. Atashroo1, E. Brett1, D. Duscher1, Z. N. Maan1, E. R. Zielins1, K. Paik1, A. Whittam1, M. Lin1, A. Luan1, A. McArdle1, C. Duldulao1, G. G. Walmsley1, M. S. Hu1, R. Tevlin1, D. C. Wan1, G. C. Gurtner1, M. T. Longaker1 1Stanford University,Hagey Laboratory For Pediatric Regenerative Medicine, Department Of Surgery, Plastic And Reconstructive Surgery Division,Palo Alto, CA, USA
Introduction: Human adipose derived stromal cells (ASCs) have emerged as a vital component in tissue engineering. Even though liposuction is the primary method of obtaining ASCs, little is known about the effects of different liposuction methods on the regenerative potential of harvested ASCs. Despite the growing popularity of ultrasound assisted liposuction (UAL) because it increase the ease, speed, and safety of harvest, a paucity of evidence exists regarding the adipogenic and osteogenic differentiation potential of cells obtained in this way. In this study, we evaluate the regenerative capacity of ASCs from third and fourth generation UAL compared to the industry standard suction assisted liposuction (SAL).
Methods: Lipoaspirate was obtained from paired elective surgery patients using UAL and SAL, and harvested for ASCs. A portion of the cells were then sorted using Fluorescence Activated Cell Sorting (FACS) based on an established progenitor surface marker profile (CD34+CD31-CD45-), and the yield of viable ASCs was compared. An MTT assay was performed on plated cells to compare their proliferation potential. Cultured cells were then differentiated towards adipogenic and osteogenic lineages. Oil Red O and Alkaline Phosphatase staining was performed at Day 7 of differentiation; Alizarin Red staining was performed at Day 14. RNA was harvested at Day 0, 7, and 14 for qRT-PCR analysis of gene expression. Paired full thickness wounds were placed on the dorsum of CD1 athymic nude mice and then a hydrogel scaffold alone or seeded with 250k SAL or UAL ASCSs was placed in the wounds. Tissue regeneration was assessed serially until complete wound closure.
Results: SAL and UAL demonstrated equivalent viable ASC yield on FACS and proliferative potential on MTT assay (*p > .05). There was no significant difference in adipogenic staining by Oil Red O, or osteogenic staining by Alkaline Phosphatase or Alizarin Red (*p > .05). Similarly qRT-PCR demonstrated non statistically significant expression of multiple osteogenic and adipogenic genes (*p > .05). Importantly, wound healing was significantly improved in both cell assisted groups compared to hydrogel alone (*p < .05); however, healing between SAL and UAL groups was equivalent (*p > .05).
Conclusion: UAL offers a similarly successful method compared to traditional SAL for obtaining ASCs for tissue engineering. Surgeons and scientists alike benefit from this additional, and arguably better, option for obtaining ASCs for cell based therapies in regenerative medicine.
