Cell-Enriched Lipotransfer (CELT) Improves Tissue Regeneration and Rejuvenation without Substantial Manipulation of the Adipose Tissue Graft

Abstract

The good availability and the large content of adult stem cells in adipose tissue has made it one of the most interesting tissues in regenerative medicine. Although lipofilling is one of the most frequent procedures in plastic surgery, the method still struggles with high absorption rates and volume losses of up to 70%. Therefore, many efforts have been made to optimize liposuction and to process the harvested tissue in order to increase fat graft retention. Because of their immunomodulatory properties, their cytokine secretory activity, and their differentiation potential, enrichment with adipose tissue-derived stem cells was identified as a promising tool to promote transplant survival. Here, we review the important parameters for lipofilling optimization. Finally, we present a new method for the enrichment of lipoaspirate with adipose tissue-derived stem cells and discuss the parameters that contribute to fat graft survival.

Keywords: adipose tissue-derived stem cells; fat grafting; lipofilling; mesenchymal stem cells; reconstructive surgery; regeneration; regenerative medicine.

Figure 1

Schematic illustration of macroscopic lipoaspirate morphology after each of the four major steps for tissue processing with the CELT protocol. (A) After it is allowed to sediment under gravitational forces, a syringe is filled with lipoaspirate (illustrated in orange). (B) After the first centrifugation, a large aqueous phase settles at the bottom of the syringe (illustrated in red) and a small oily phase separates at the top of the syringe (illustrated in yellow). The size of the aqueous phase varies depending on the time the tissue is allowed to sediment. The size of the oily phase varies depending on the shear stress the harvesting method has exerted. (C) After the aqueous and oily phases have been discarded, shear-force mechanical processing via intersyringe processing can occur. (D) After mechanical processing and a second centrifugation, a small aqueous and a large oily phases separate from the tissue at the syringe’s top and bottom, respectively. (E) After the aqueous and oily phases have been discarded, a stem cell-enriched lipograft tissue is ready for clinical application.