Cell therapy for bone fracture repair: A comparative preclinical review of mesenchymal stromal cells from bone marrow and from adipose tissue

Abstract

Over the last decade, there has been an increasing interest among researchers for human mesenchymal stromal cells (MSC). Their regenerative properties, multilineage differentiation capacity and immunomodulatory properties make them promising candidates for treatment in various conditions. Emerging biotechnology companies specialized in cellular and regenerative therapies have been focusing their interest on MSC-based therapies, and their use in clinical trials has steadily increased. Notably, MSC are currently tested in clinical trials addressing unmet medical needs in the field of bone fracture repair and more specifically in non-union and delayed union fractures where the bone repair process is impaired. Although MSC can be isolated from various tissues, the most commonly studied sources are bone marrow (BM) and adipose tissue (Ad). In this article, we reviewed the literature directly comparing BM- and Ad-MSC for their in vitro characteristics and in vivo osteogenic potential to determine which source of MSC would be more appropriate for bone fracture repair. As considerable variations in experimental settings between studies were found, our review was based on studies meeting specific sets of criteria, notably regarding donors’ age and gender. This review of side-by-side comparisons suggests that while BM-and Ad-MSC share common general characteristics, BM-MSC have a higher intrinsic osteogenic capacity in vitro and bone repair potential in vivo.