Abstract: Mechanical Processing of Emulsified Lipoaspirate Results in a Dose-Dependent Upregulation of Stem Cell Markers and Populations (Plastic Surgery The Meeting)

Saturday, September 24, 2016: 1:15 PM

Derek A. Banyard, MD, MBA , Plastic Surgery, University of California, Irvine, Orange, CA

Christos N. Sarantopoulos, BS , Plastic Surgery, University of California, Irvine, Orange, CA

Ryan S. Chiang, BS , Plastic Surgery, University of California, Irvine, Orange, CA

Anna A. Borovikova, MD , Plastic Surgery, University of California, Irvine, Orange, CA

Xiaolong Qiu, BS, MS , Biomedical Engineering, University of California, Irvine, Irvine, CA

Jered Haun, PhD , Biomedical Engineering, University of California, Irvine, Irvine, CA

Keyianoosh Z. Paydar, MD, FACS , Plastic Surgery, University of California, Irvine, Orange, CA

Garrett A. Wirth, MD, MS, FACS , Wirth Plastic Surgery, Newport Beach, CA

Gregory R.D. Evans, MD, FACS , Plastic Surgery, University of California Irvine, Orange, CA

Alan D. Widgerow, MBBCh, MMed, FCS, FACS , Plastic Surgery, University of California, Irvine, Orange, CA

Presentation PDF file

Introduction

Mechanical processing of lipoaspirate (LA) is a commonly employed technique prior to reinjection for the purposes of lipofilling and skin rejuvenation. Our group has previously demonstrated that one form of mechanical processing, ‘nanofat grafting,’ results in a significant upregulation of multipotent mesenchymal stem cell (MSC) markers, adipose-derived stem (ADSCs) and endothelial progenitor cell populations (EPCs) [1]. Recently, a pluripotent population termed multilineage stress-enduring (Muse) cells was described after subjecting lipoaspirate to various extreme stress conditions [2]. Based on these findings, we hypothesized that modulation of shear-stress alone would result in a correlative induction of markers associated with multipotency and/or pluripotency.

Methods

Two microfluidic devices were created from acrylics and methacrylic ester using laser etching and 3D printing. Each multichannel construct consists of expansion and constriction regions with maximum widths of 4 mm (v4) or 2 mm (v2) where the narrower the channel, the greater shear force generated. Standard LA (n = 4) was set aside as a control or processed as nanofat [3]. Subsequently, two nanofat samples were processed via microfluidic devices regulated by a syringe pump (12.5 ml/min for 10 passes). Finally, each sample was subjected to collagenase digestion and the resulting stromal vascular fraction (SVF) pellets were subjected to automated cell count and multicolor flow cytometry panels.

Results

On average, nanofat processing with or without microfluidic device yielded a four-fold decrease in nucleated cells when compared to control SVF. A dose-dependent pattern of stress-to-phenotype induction was observed for markers CD34, CD146 and CD13, as well as the subpopulations of Muse cells, EPCs and ADSCs. The upregulation of MSC and Muse cells was much greater in all mechanically emulsified groups when compared to control (p < 0.04). The induction of EPCs, ADSCs and pericytes also trended in a similar fashion with v2 stress resulting in the largest populations.

Conclusion

Mechanical shear stress results in a dose-dependent induction of mesenchymal stem cell markers as well as multipotent/pluripotent populations. A larger sample with more detailed in vitro and in vivo studies is currently being explored to determine the optimal stress needed to produce a potent progenitor mix for clinical applications.

29163 Mechanical Processing of Emulsified Lipoaspirate Results in a Dose-Dependent Upregulation of Stem Cell Markers and Populations