Adipose-Derived Stromal Cell-Based Therapies for Radiation-Induced Fibrosis

Significance: Half of all cancer patients receive radiation therapy as a component of their treatment regimen, and the most common resulting complication is radiation-induced fibrosis (RIF) of the skin and soft tissue. This thickening of the dermis paired with decreased vascularity results in functional limitations and esthetic concerns and poses unique challenges when considering surgical exploration or reconstruction. Existing therapeutic options for RIF of the skin are limited both in scope and efficacy. Cell-based therapies have emerged as a promising means of utilizing regenerative cell populations to improve both functional and esthetic outcomes, and even as prophylaxis for RIF. Recent Advances: As one of the leading areas of cell-based therapy research, adipose-derived stromal cells (ADSCs) demonstrate significant therapeutic potential in the treatment of RIF. The introduction of the ADSC-augmented fat graft has shown clinical utility. Recent research dedicated to characterizing specific ADSC subpopulations points toward further granularity in understanding of the mechanisms driving the well-established clinical outcomes seen with fat grafting therapy. Critical Issues: Various animal models of RIF demonstrated improved clinical outcomes following treatment with cell-based therapies, but the cellular and molecular basis underlying these effects remains poorly understood. Future Directions: Recent literature has focused on improving the efficacy of cell-based therapies, most notably through (1) augmentation of fat grafts with platelet-rich plasma and (2) the modification of expressed RNA through epitranscriptomics. For the latter, new and promising gene targets continue to be identified which have the potential to reverse the effects of fibrosis by increasing angiogenesis, decreasing inflammation, and promoting adipogenesis.

Application of adipose-derived stromal cells in fat grafting: Basic science and literature review

Autologous fat is considered the ideal material for soft-tissue augmentation in plastic and reconstructive surgery. The primary drawback of autologous fat grafting is the high resorption rate. The isolation of mesenchymal stem cells from adipose tissue inevitably led to research focusing on the study of combined transplantation of autologous fat and adipose derived stem cells (ADSCs) and introduced the theory of ‘cell-assisted lipotransfer’. Transplantation of ADSCs is a promising strategy, due to the high proliferative capacity of stem cells, their potential to induce paracrine signalling and ability to differentiate into adipocytes and vascular cells. The current study examined the literature for clinical and experimental studies on cell-assisted lipotransfer to assess the efficacy of this novel technique when compared with traditional fat grafting. A total of 30 studies were included in the present review. The current study demonstrates that cell-assisted lipotransfer has improved efficacy compared with conventional fat grafting. Despite relatively positive outcomes, further investigation is required to establish a consensus in cell-assisted lipotransfer.