A Review of Cell-Based Strategies for Soft Tissue Reconstruction

Soft tissue reconstruction to restore volume to damaged or deficient tissue beneath the skin remains a challenging endeavor. Current techniques are centered around autologous fat transfer, or the use of synthetic substitutes, however, a great deal of scientific inquiry has been made into both the molecular mechanisms involved in, and limitations of, de novo adipogenesis, that is, the formation of new adipose tissue from precursor cells. To best comprehend these mechanisms, an understanding of defined markers for adipogenic differentiation, and knowledge of both commercially available and primary cell lines that enable in vitro and in vivo studies is necessary. We review the growth factors, proteins, cytokines, drugs, and molecular pathways that have shown promise in enhancing adipogenesis and vasculogenesis, in addition to the multitude of scaffolds that act as delivery vehicles to support these processes. While progress continues on these fronts, equally important is how researchers are optimizing clinically employed strategies such as autologous fat transfer through cell-based intervention, and the potential to augment this approach through isolation of preferentially adipogenic or angiogenic precursor subpopulations, which exists on the horizon. This review will highlight the novel molecular and synthetic modifications currently being studied for inducing adipose tissue regeneration on a cellular level, which will expand our arsenal of techniques for approaching soft tissue reconstruction.