Chapter 19 - Adipose stem cells for peripheral nerve engineering

Abstract

US healthcare expenditures remain in the hundreds of billions of dollars for treating peripheral nerve injury (PNI) every year, and therapies that advance the standard of care are critically necessary. Further, there is a profound socioeconomic impact resulting from PNI, as four of every 10 individuals experiencing these injuries do not return to work 1 year postoperatively owing to residual complications. As the prevalence and acceptance of clinical cellular therapies continue to increase, cell-based treatments that complement or augment current care for nerve injury are being introduced. The use of adipose-derived stem cells (ASCs) may be the ideal candidate for such investigation. ASCs are convenient to harvest relative to other stromal cells, have been shown to mediate injury-induced inflammation, and are able to be differentiated into phenotypes relevant to neural repair in vitro. Further, ASCs have shown in several studies their ability to secrete nerve-specific cytokines, including neural growth factor (NGF), glial cell line-derived neurotrophic factor (GDNF), and brain-derived neurotrophic factor (BDNF). In vivo studies have shown ASCs to be capable of regenerating neuromuscular function, increasing Schwann cell presence, and reducing scar formation, though the attempts to translate ASC therapies for PNI clinically have not been realized. While there are nearly 400 investigations registered on ClinicalTrials.gov related to ASC therapies, there are currently (as of late 2020) no studies seeking to utilize ASCs for PNI. Based on the myriad of promising preclinical data, however, the prospective utility of ASC therapies is seemingly soon to be realized.