The essential roles of human adipose tissue: Metabolic, thermoregulatory, cellular, and paracrine effects

Introduction: Over the past decade, human adipose-derived mesenchymal stem/signaling/stromal cell (ADSC) therapies have become increasingly popular as a biologic treatment for a variety of orthopedic conditions. ADSCs represent a source of stromal cells with biologic properties that allow for paracrine and immunomodulatory functions and the ability to differentiate into various downstream cellular tissues. Before considering the use of adipose tissue as a cellular source, it is imperative to understand its anatomy and physiology and its roles in the human body. Objectives: To review the current literature regarding the anatomy, physiology, and various roles of human adipose tissue, as well as harvesting techniques and its role in biologic therapy. Methods: A comprehensive literature review that included searches of PubMed, medline, EMBASE, and Google Scholar database(s), including both preclinical and clinical studies, was performed. Results: This manuscript represents an updated understanding of adipose tissue, including its anatomy, functions in the human body, and role as a perivascular cellular source for tissue renewal, in addition to its role in providing cushioning and support to various structures. Conclusion: Adipose tissue is widespread throughout the body and serves multiple physiologic functions. It can be harvested through several techniques and is an abundant source of bioactive molecules and ADSCs. Research in orthopedic surgery has begun using adipose tissue as a source of homologous and non-homologous cell and tissue applications. Future study will continue to investigate optimal sources of adipose-derived cells and tissues, and its therapeutic applications in orthopedics.